The requirements in paragraph (e), including those regarding biosafety cabinets, are derived primarily from the CDC/NIH recommendations found in "Biosafety in Microbiological and Biomedical Laboratories" (Ex. 7-72). Only those provisions that relate to the health and safety of employees are required by the standard. The provisions in paragraph (e) are a minimal program, and OSHA anticipates that employers affected by this paragraph will continue to follow any other appropriate portions of the above recommendations in addition to the requirements of this standard. In addition, the employer is responsible for following this entire standard (e.g. training employees, medical surveillance).

Paragraph (e) applies to two types of facilities that OSHA has designated as "clinical laboratories" and "research laboratories." For the purpose of this standard a clinical laboratory is a laboratory or area of a facility that conducts routine and repetitive operations for the diagnosis of TB, such as preparing acid-fast smears and culturing sputa or other clinical specimens for identification, typing or susceptibility testing. A research laboratory is a laboratory that propagates and manipulates cultures of M. tuberculosis in large volumes or high concentrations that exceed those used for the identification and typing activities common to clinical laboratories.

The proposed standard requires, in paragraphs (e)(2)(i)(A) through (D), that both clinical and research laboratories follow several standard microbiological practices. All procedures are to be performed in a manner that minimizes the creation of aerosols. In view of the mode of transmission of M. tuberculosis, that is, through inhalation of airborne organisms, this provision is extremely important in eliminating or minimizing employee exposure. It is the responsibility of the employer to evaluate laboratory tasks and institute the measures necessary to minimize the creation of aerosols.

OSHA also proposes to adopt the good laboratory and infection control practice of prohibiting pipetting or suctioning by mouth. The use of cotton plugs or other barriers does little to reduce the hazards of mouth pipetting. Even a technician who is skilled in mouth pipetting may inadvertently suck fluids containing M. tuberculosis into the mouth. In addition to producing M. tuberculosis-containing aerosols when the fluid is expelled, these fluids may also contain bloodborne pathogens that would have contacted the employee's mucous membranes (i.e., the mouth) as well as any blisters, cuts, or other lesions in the mouth or on the lips.

Work surfaces and laboratory equipment must be decontaminated at the end of each shift and after any spill of viable material. This is recognized as good laboratory practice in minimizing the spread of contamination.

Finally, the proposed standard requires that all cultures, stocks, and other wastes contaminated with M. tuberculosis be decontaminated before disposal by a decontamination method, such as autoclaving, known to effectively destroy M. tuberculosis. Materials to be decontaminated outside of the immediate laboratory are to be placed in a durable leakproof container, closed to prevent leakage for transport from the laboratory, and labeled or color coded in accordance with paragraph (h)(1)(ii) of this section. Decontamination before disposal helps assure that other employees are not inadvertently exposed to the bacterium.

Although the proposed standard requires proper containerization of laboratory wastes, it includes no such requirement for wastes originating from the provision of care or services to individuals with suspected or confirmed infectious TB (e.g., facial tissues that the individual has used). The reason for this is that items, such as facial tissues, capture and contain the liquids generated by the individual. Once captured, the liquid is not readily aerosolized. In their guidelines, the CDC states:

Disposable items contaminated with respiratory secretions are not associated with transmission of M. tuberculosis. (Ex. 4B)

In the laboratory, however, the liquids containing M. tuberculosis are generally not captured or contained on an item but exist as an individual specimen or culture. Also, in some instances, the bacilli have been concentrated. The possibility, therefore, for formation of droplet nuclei from these wastes is increased. Consequently, it is necessary to properly containerize and label laboratory wastes to assist in preventing droplet nuclei formation and possible infection. Proper containerization and labeling of wastes to be decontaminated outside a laboratory not only help prevent employee exposure but also warn employees who come in contact with this waste of the hazard within the container.

Paragraphs (e)(2)(ii)(A) through (E) describe special practices to be followed in clinical and research laboratories, such as limiting access to the laboratory to authorized personnel, preparing and maintaining a biosafety manual, properly containerizing materials contaminated with M. tuberculosis, immediately containerizing and cleaning up all spills potentially contaminated with M. tuberculosis, and posting a sign with the universal biohazard symbol on access doors when materials containing or animals infected with M. tuberculosis are present. Limiting access to these laboratories assures that unauthorized individuals are not placed at risk, and that they do not distract or otherwise interfere with the activity of the authorized employees. This provision works in concert with the requirement for signs in paragraph (h)(2)(iv) and ensures that only employees who meet the special requirements set forth by the laboratory director, which will include training, personal protective equipment, and other requirements, could enter the area.

The requirement for a biosafety manual helps assure that any additional procedures are developed to address situations that are unique to a particular facility and to provide appropriate protection to exposed employees. The manual must be reviewed as necessary and at least annually. The manual must also be updated as necessary to reflect changes in the work setting. The phrase "as necessary" has been used to indicate that updating of the manual to reflect work setting changes is to be done as soon as possible and is not to be postponed until the annual review. Employees are required to read the biosafety manual's sections on potential hazards and practices and procedures.

The requirement that contaminated material removed from the work area be placed in a container that prevents leakage during collection, handling, processing, storage, transport, or shipping is to assure that there are no accidental spills or other contamination that may place other employees at risk.

Paragraph (e)(2)(ii)(D) requires that spills be cleaned up immediately by employees trained and equipped to work with potentially concentrated M. tuberculosis. Because M. tuberculosis can become aerosolized during cleanup procedures, the task cannot be done by someone who is not skilled and properly equipped. In addition, exposure incidents must be reported so that the post-exposure management and follow-up required by paragraph (g) can be initiated and the circumstances surrounding the exposure incidents can be investigated.

Paragraph (e)(2)(ii)(E) requires that, when materials or animals infected with M. tuberculosis are present in the laboratory, a hazard warning sign, in accordance with paragraph (h)(2)(iv) of Communication of Hazards and Training, incorporating the universal biohazard symbol, shall be posted on all laboratory and animal room access doors. Because M. tuberculosis is present in the materials listed above, it is necessary to warn individuals who may enter this area of the hazards that are present so that they can take proper precautions to guard themselves against exposure.

The requirements of paragraph (e)(2)(iii)(A) stipulate that whenever activities with the potential for generating aerosols of M. tuberculosis are conducted, and whenever high concentrations or volumes of M. tuberculosis are used, a certified Class 2 biological safety cabinet must be used. Such materials may be centrifuged in the open laboratory, i.e., outside of a biosafety cabinet, if sealed rotor heads or centrifuge safety cups are used. These requirements protect employees from exposure during the performance of procedures by assuring that aerosolized M. tuberculosis will be contained and kept away from the worker's breathing zone.

Paragraph (e)(2)(iii)(B) requires that biological safety cabinets shall be certified when they are installed, annually thereafter, whenever they are moved, and whenever filters are changed. Biological safety cabinets must be certified to ensure that they will provide the proper protection. The National Sanitation Foundation (NSF) Standard 49 describes design, construction, and performance criteria for biosafety cabinets. (Ex. 7-135) Moreover, this NSF standard is subject to periodic review by the NSF in order to keep the requirements consistent with new technology. OSHA has incorporated the current NSF Standard 49 performance criteria into the OSHA standard. For example, Standard 49 states:

* * * that each cabinet be tested and performance evaluated on site, assuring that all physical containment criteria are met at the time of installation, prior to use, and periodically thereafter. (Ex. 7-135)

NSF Standard 49 also calls for recertification of cabinets at least annually, when HEPA filters are changed, and after maintenance repairs or relocation of a cabinet. Therefore, OSHA believes that the requirements in the proposed standard are appropriate and that cabinets that are certified by the manufacturer as Class 2 or 3 will provide adequate protection to employees.

Paragraph (e)(2)(iv) requires that a method for decontamination of wastes contaminated with M. tuberculosis (e.g., autoclave, chemical disinfection, incinerator, or other approved decontamination system known to effectively destroy M. tuberculosis) must be available within or as near as feasible to the work area. The availability of such methods of decontamination is required for inactivating or destroying M. tuberculosis in or on a variety of media, including culture fluids, plastic ware, and equipment. These materials must be decontaminated to prevent potential aerosolization of M. tuberculosis and inadvertent exposure of employees outside of the laboratory.

Research laboratories working with M. tuberculosis are held to several additional requirements. Paragraph (e)(3)(i)(A) requires that research facilities keep laboratory doors closed when working with M. tuberculosis. Paragraph (e)(3)(i)(B) requires that access to the work area be limited to persons who comply with specified entry and exit requirements. These provisions are adopted from the CDC/NIH recommendations for "Biosafety in Microbiological and Biomedical Laboratories" (Ex. 7-72). In addition, paragraph (e)(3)(i)(C) requires that respiratory protection shall be worn in research laboratories when aerosols cannot be safely contained (e.g., when aerosols are generated outside a biological safety cabinet). As stated previously, research laboratories are working with larger volumes and higher concentrations of M. tuberculosis than clinical laboratories. As such, the risk to employees from aerosolized bacilli is increased, necessitating that these employees be protected whenever lapses in containment occur. An example of when aerosols would be generated would be when a flask containing M. tuberculosis is dropped and broken outside of the biosafety cabinet. Another example would be centrifugation of M. tuberculosis-containing cultures in an open centrifuge without aerosol-proof centrifuge safety containers, or utilizing such containers but then opening them outside of the biosafety cabinet (Ex. 7-134).

Paragraph (e)(3)(ii) requires employers to ensure that employees manipulating cultures and clinical or environmental materials that may generate M. tuberculosis-containing aerosols, challenging animals with M. tuberculosis aerosols, harvesting tissues or fluids from infected animals, or performing necropsies on infected animals use the appropriate containment equipment and/or devices when performing these activities. Such equipment and devices include Class 2 or 3 biosafety cabinets, or appropriate combinations of personal protective equipment and physical containment devices (such as respirators, centrifuge safety cups, sealed centrifuge rotors, and containment caging for animals). This requirement, like the others in this paragraph, is intended to ensure that employees are protected during the performance of these potentially high-hazard procedures.

Research laboratories are also held to additional requirements with regard to facility construction. Paragraph (e)(3)(iii)(A) requires that the laboratory be separated from areas that are open to unrestricted traffic flow within the building. Passage through two sets of self-closing doors is the requirement for entry into the work area from access corridors or other contiguous areas. This type of entrance reduces the likelihood of untrained employees accidentally entering the work area, since such entry necessitates deliberate action on the part of the individual.

Paragraph (e)(3)(iii)(B) requires that windows in the laboratory be closed and sealed. This helps assure containment of any aerosols and helps maintain proper operation of biosafety cabinets through minimization of cross drafts.

Paragraph (e)(3)(iii)(C) requires that a ducted exhaust air ventilation system shall be provided which creates directional airflow that draws air from clean areas into the laboratory toward contaminated areas. The proper direction of the airflow shall be verified (i.e., into the work area) by the employer at least every six months. The exhaust air shall not be recirculated to any other area of the building, shall be discharged to the outside, and shall be dispersed away from occupied areas and air intakes. The requirement that research laboratories have verified directional airflow into the work area is to assure that air is drawn into the laboratory toward contaminated areas to assist in maintaining containment of aerosols within the laboratory.

Paragraph (e)(3)(iii)(D) requires that the HEPA-filtered exhaust from Class 2 or 3 biosafety cabinets is to be discharged to the outside of the building or through the building exhaust system. If it is discharged through the building exhaust system, it must be connected to this system in a manner that avoids any interference with the air balance of the cabinets or the building exhaust system. This is required to assure that biosafety cabinets and the building exhaust system continue to function as intended.

Paragraph (e)(3)(iii)(E) requires that continuous flow centrifuges or other equipment that may produce aerosols must be contained in devices that exhaust air through a HEPA filter before discharge into the laboratory. This assures that any aerosols which may contain M. tuberculosis are effectively filtered from the exhaust air before discharge into the laboratory, thereby protecting employees against inadvertent exposure.

All of the requirements discussed above were derived directly from the CDC/NIH's "Biosafety in Microbiological and Biomedical Laboratories." OSHA requests comment on the applicability and OSHA's application of CDC/NIH's guidelines for their use in laboratories which handle M. tuberculosis.

Paragraph (f) Respiratory Protection

Respirators serve as supplemental protection to reduce employee exposures when engineering and work practice controls are not sufficient to provide adequate protection against airborne contaminants.

At the opening of the public hearings for the revision of OSHA's General Industry Respiratory Standard, 29 CFR 1910.134, the Agency stated that all aspects of respirator use for protection against tuberculosis would be addressed in the rulemaking for Occupational Exposure to Tuberculosis. Consequently, the respiratory protection portion of this proposal contains all of the respiratory protection provisions that have been preliminarily determined to be applicable to respirator use for TB. In the past, OSHA standards have referred to the Respirator Standard (29 CFR 1910.134) for the general requirements for respirator use (e.g., written respiratory protection program; respirator maintenance) and have included only the respirator provisions specific to the hazard addressed by the standard. OSHA's approach in this proposal, however, is to include provisions relative to all aspects of respirator use for tuberculosis. This will provide interested parties with the opportunity to review and comment on these aspects. To assure consistency across OSHA respiratory protection standards, however, OSHA is considering including in the final TB rule cross-referencing to the general requirements of the Respiratory Protection Standard (29 CFR 1910.134) and retaining in the final TB rule only those provisions specific to respirator use for TB. OSHA seeks comment on this intended approach in the final standard for TB.

Paragraph (f)(1)(i) states that each employer must provide a respirator to each employee who: (A) enters an AFB isolation room or area in use for TB isolation; (B) is present during performance of procedures or services for an individual with suspected or confirmed infectious TB who is not masked; (C) transports an individual with suspected or confirmed infectious TB in an enclosed vehicle or who transports an individual with suspected or confirmed infectious TB within the facility whenever that individual is not masked; (D) repairs, replaces, or maintains air systems or equipment that may reasonably be anticipated to contain aerosolized M. tuberculosis; (E) is working in an area where an unmasked individual with suspected or confirmed infectious TB has been segregated or otherwise confined (e.g., while awaiting transfer), and (F) is working in a residence where an individual with suspected or confirmed infectious TB is known to be present. In addition, paragraph (f)(1)(ii) requires that each employer who operates a research laboratory provide a respirator to each employee who is present when aerosols of M. tuberculosis cannot be safely contained.

In discussing the use of respiratory protection in their guidelines, CDC states:

Personal respiratory protection should be used by (a) persons entering rooms where patients with known or suspected infectious TB are being isolated, (b) persons present during cough-inducing or aerosol-generating procedures performed on such patients, and (c) persons in other settings where administrative and engineering controls are not likely to protect them from inhaling infectious airborne droplet nuclei. These other settings include transporting patients who may have infectious TB in emergency transport vehicles and providing urgent surgical or dental care to patients who may have infectious TB before a determination has been made that the patient is noninfectious. (Ex. 4B)

The guidelines also state that respiratory protection should be worn by personnel who are performing maintenance and testing procedures on HEPA filtration systems (Ex. 4B). Furthermore, the CDC/NIH document "Biosafety in Microbiological and Biomedical Laboratories" recommends that respiratory protection be worn whenever aerosols of organisms such as M. tuberculosis cannot be safely contained (Ex. 7-72). Consequently, employees who may need to wear respirators could include not only health care providers but also employees such as housekeepers, dietary personnel, laboratory technicians, employees in intake areas, maintenance personnel, social workers, and so forth. It is the employer's responsibility to determine which occupationally exposed employees would be covered under this provision and, therefore, would need to wear a respirator.

With regard to utilization of respiratory protection when entering an AFB isolation room or area, the reader is referred to the definition of "AFB isolation room or area" in paragraph (j), Definitions. This definition clarifies that the requirement refers not only to situations such as entering a patient room occupied by an individual with suspected or confirmed infectious TB but also refers to entering any area where high-hazard procedures are being performed and entering an autopsy room where M. tuberculosis may be aerosolized.

Paragraph (f)(1)(i)(B) requires respirator use when an employee is present during performance of procedures or services for an unmasked individual with suspected or confirmed infectious TB. This provision is intended to cover those situations in which a procedure or service is performed outside of an AFB isolation room or area. For example, a facility may not have a portable X-ray and may, therefore, perform this procedure in a standard X-ray room. If the individual is not masked in such a situation, all employees present (i.e., the X-ray technician and any other employees in the room) must utilize respiratory protection.

As stated previously under discussion of Scope, employees rendering emergency medical services may spend time in very close proximity to individuals with suspected or confirmed infectious TB within an enclosed vehicle. Even though the individual may be masked, droplet nuclei that escape capture in the mask are contained within the vehicle, thereby increasing the likelihood that employees will breathe droplet nuclei generated when the patient coughs or speaks. In addition, under paragraph (f)(1)(i)(D), employees who repair, replace, on maintain air systems or equipment that may reasonably be anticipated to contain aerosolized M. tuberculosis are at risk of occupational exposure as a result of exposure to air that could contain aerosolized bacilli. Therefore, respirator use would be required in this situation.

As discussed under Scope, aerosolized M. tuberculosis is a recognized hazard to laboratory personnel. When aerosols of M. tuberculosis cannot be safely contained, such as during a spill, the employer is required to provide a respirator to each employee who is present during this time. This is consistent with CDC/NIH recommendations regarding respirator use in research laboratories (Ex. 7-72).

Unlike some other airborne contaminants, the quantity of M. tuberculosis that, when inhaled, will result in infection (i.e., infectious dose) has not been determined conclusively. The number of droplet nuclei expelled into a room by an infectious individual or aerosol-producing procedure and the concentration of droplet nuclei in a room or area are unknown. Consequently, there is no basis to judge the effectiveness of other control measures present even though they may be operating as intended. OSHA therefore agrees with the CDC that, in the above situations, other controls that may be in place cannot be assumed to adequately protect employees against exposure to airborne TB droplet nuclei and therefore that the use of respiratory protection is necessary.

While OSHA agrees with and has adopted most of the CDC's recommendations regarding when respiratory protection is necessary, the Agency has extended respirator use to two additional situations. More specifically, when an individual with suspected or confirmed infectious TB is not masked and is transported within a facility, the employee transporting the individual must wear a respirator. While CDC recommends masking individuals with suspected or confirmed infectious TB prior to transporting them, there may be special circumstances in which the individual may not be masked (e.g., individual is combative and will not wear a mask). The employee transporting the individual would most likely spend an extended period of time in close proximity to the individual, either walking beside or behind (e.g., pushing a wheelchair) the individual. The employee would, therefore, be walking directly through the airspace into which the individual would be expelling droplet nuclei, receiving exposure each time the individual coughed, resulting in multiple relatively concentrated exposures. In view of this, the latter portion of paragraph (f)(1)(i)(C) addresses the Agency's belief that it is necessary and justified that respiratory protection be worn by the employee to protect against occupational exposure if the individual is not masked.

The second situation, under paragraph (f)(1)(i)(E), requires respirator use by an employee when working in an area where an unmasked individual with suspected or confirmed infectious TB has been segregated or otherwise confined, for example while awaiting transfer. As discussed above, it is assumed that such individuals would normally be masked. Here again, however, there may be circumstances that preclude the individual from being masked (e.g., the individual is combative). Therefore, employees who must work in the area where these unmasked individuals are located, whether working directly with the individual or performing other duties, must wear a respirator to protect against possible tuberculosis infection.

Paragraph (f)(1)(i)(F) requires that a respirator be worn by an employee who is working in a residence where an individual with suspected or confirmed infectious TB is known to be present. In this situation, whether the individual is masked or unmasked does not trigger respirator use since the individual has been releasing droplet nuclei into the residence airspace. The CDC refers to this type of situation in its discussion of the provision of home health care and states:

Health care workers who provide medical services in the homes of patients who have suspected or confirmed infectious TB should instruct such patients to cover their mouths and noses with a tissue when coughing or sneezing. Until such patients are no longer infectious, HCWs should wear respiratory protection when entering these patients' homes. (Ex. 4B)

In addition to home health care and home-based hospice care workers, other employees, such as social workers who are entering these residences, would come under this provision. It is the Agency's intent that a respirator be used by an employee in these situations for the time that the employee is in the residence and that respirator use continue until the individual is noninfectious.

The proposed standard, in paragraphs (f)(1)(iii) and (f)(1)(iv), places several general responsibilities upon the employer regarding respiratory protection. Paragraph (f)(1)(iii) states that where respirators are required by the standard, the employer shall provide them at no cost to the employee and assure that they are used in accordance with the requirements of the standard. Paragraph (f)(1)(iv) stipulates further that the employer must assure that the employee dons a respirator before entering the work settings or performing the tasks set forth in paragraphs (f)(1)i and (f)(1)(ii) above and uses it until leaving the work setting or completing the task, regardless of other control measures in place.

It has been OSHA's long-standing policy to hold the employer responsible for controlling exposure to hazards in his or her workplace and to fulfill this responsibility at no cost to the employee. Therefore, the financial burden for purchasing and providing personal protective equipment, including respirators, rests upon the employer just as it does for all other control measures (e.g., engineering controls). OSHA believes that in order to assure that employees are adequately protected, the employer has the responsibility not only to provide respiratory protection, but also to assure that it is utilized when necessary. Furthermore, respiratory protection must be donned prior to entering the above work settings or performing the tasks, for the period of time that the employee remains in these work settings, and must not be removed until the employee leaves the work setting or completes the tasks. In this way, the employee is protected for the entire period of occupational exposure.

It is not OSHA's intent that each employee be monitored constantly for compliance; however, the Agency does believe that the employer has the power to assure that employees follow specific rules. For example, most employers have requirements that they require employees to follow, such as reporting to work on time, working a minimum number of hours per day, notifying the employer when the individual is unable to report for work, and taking certain precautions to prevent nosocomial infections. Following these requirements is not left to the employee's discretion, and employers generally have some process to ensure conformance with these procedures. Therefore, the Agency believes that the employer has not only the responsibility, but also the ability, to assure that respiratory protection is used in accordance with the requirements of this section.

Paragraph (f)(2)(i) requires that each employer who has any employee whose occupational exposure is based on entering any of the work settings or performing any of the tasks described in paragraph (f)(1) must establish and implement a written respiratory protection program that assures that respirators are properly selected, fitted, used, and maintained. The program must include the following elements: (A) Procedures for selecting respirators for use in the work setting; (B) a determination of each employee's ability to wear a respirator, as required under paragraph (g)(3)(ii), Medical Surveillance, for each employee required to wear a respirator; (C) procedures for the proper use of respirators; (D) fit testing procedures for tight-fitting respirators; (E) procedures and schedules for cleaning, disinfecting, storing, inspecting, repairing, or otherwise maintaining respirators; (F) training of employees to assure the proper use and maintenance of the respirators as required under paragraph (h), Communication of Hazards and Training; and (G) procedures for periodically evaluating the effectiveness of the program. Written standard operating procedures are essential to an effective respiratory protection program. Developing and writing down standard operating procedures require employers to think through how all of the requirements pertaining to respirators will be met in their workplace. In addition, this provision assures that the employer establishes standardized procedures for selecting, using, and maintaining respirators in the workplace. OSHA's long-standing position has been that a systematic respiratory protection program is necessary to provide for consistency in protection. Guidance that has been developed by an outside party (e.g., a respirator manufacturer) on the general use of a particular respirator would not address the site-specific aspects of the employer's work setting and would not be an appropriate substitute for a respiratory protection program.

Paragraph (f)(2)(ii) requires the employer to designate a person qualified by appropriate training or experience to be responsible for the administration of the respiratory protection program and for conducting the required periodic evaluations of its effectiveness. To assure that the integrity of the respiratory protection program is maintained through the continuous oversight of one responsible individual, OSHA is proposing that a qualified person be designated as responsible for the administration of the program. That individual can work with a committee or assign responsibility for portions of the program to other personnel, but the overall responsibility for the operation of the program remains with the designated person. This approach ensures coordination of all facets of the program. The level of training or experience necessary for a designated person has been left performance oriented since this will vary with the complexity of the respirator program. However, the person chosen would need to have sufficient knowledge of respiratory protection and the workplace to properly supervise the program.

Employers are required, in paragraph (f)(2)(iii), to review and update the written program as necessary to reflect current workplace conditions and respirator use. Reviewing and updating will assure that the program addresses current conditions. The reason OSHA has not set a schedule for reviewing the program is because conditions may change frequently in some work settings while remaining relatively stable in others. Thus, the employer determines the frequency of the review. However, when an employer is aware of changes in the workplace or respirator use which could necessitate changes in the written program, it is not appropriate to delay revising the written program. OSHA's use of the phrase "as necessary" in the requirement is intended to assure that such changes are incorporated into the written program expeditiously. As the workplace situation or respirator use changes, the program is to be revised. In addition, paragraph (f)(2)(iv) requires that employers, upon request, make the written respiratory protection program available to affected employees, their designated representatives, the Assistant Secretary, and the Director. This provision also requires that a copy of the program be submitted to the Assistant Secretary and/or the Director, if requested.

Paragraph (f)(3) sets out the respirator characteristics that must be satisfied in order to provide employees with a respirator that will protect them against aerosolized M. tuberculosis. These criteria are presented in performance-oriented language to provide flexibility in choice of respirators and have been drawn from CDC recommendations (Ex. 4B). CDC has based these criteria on currently available information relative to respirators that includes:

* * * (a) data on the effectiveness of respiratory protection against noninfectious hazardous material in workplaces other than health-care settings and on an interpretation of how these data can be applied to respiratory protection against M. tuberculosis; (b) data on the efficiency of respirator filters in filtering biological aerosols; (c) data on face-seal leakage; and (d) data on the characteristics of respirators that were used in conjunction with administrative and engineering controls in outbreak settings where transmission to HCWs and patients was terminated (Ex. 4B).

The CDC Guidelines go on to state:

Available data suggest that infectious droplet nuclei range in size from 1 [micron] to 5 [microns]; therefore, respirators used in health-care settings should be able to efficiently filter the smallest particle in this range. Fifty liters per minute is a reasonable estimate of the highest airflow rate an HCW is likely to achieve during breathing, even while performing strenuous work activities (Ex. 4B).

In their 1994 TB guidelines, the CDC states:

Respiratory protective devices used in health-care settings for protection against M. tuberculosis should meet the following standard performance criteria:

1. The ability to filter particles 1 um in size in the unloaded state with a filter efficiency of < 95 % (i.e., filter leakage of < 5 %), given flow rates of up to 50 L per minute.

2. The ability to be qualitatively or quantitatively fit tested in a reliable way to obtain a face-seal leakage of < 10 %.

3. The ability to fit different facial sizes and characteristics of HCWs [health care workers], which can usually be met by making the respirators available in at least three sizes.

4. The ability to be checked for facepiece fit, in accordance with standards established by the Occupational Safety and Health Administration (OSHA) and good industrial hygiene practice, by HCWs each time they put on their respirators. (Ex. 4B)

The various respirator provisions that OSHA is proposing rely heavily on the CDC's aforementioned respirator performance criteria. The second, third, and fourth CDC criteria are addressed by paragraphs (f)(3)(i) (A) and (B) and paragraph (f)(5)(ii). Paragraph (f)(3)(i) requires the employer to select and provide properly fitted negative pressure or more protective respirators. Negative pressure respirators must be capable of being: (A) Qualitatively or quantitatively fit tested in a reliable way to verify a face-seal leakage of no more than 10 %; and (B) fit checked by the employee each time the respirator is donned. Paragraph (f)(5)(ii) requires that employers assure that each employee who must wear a tight-fitting respirator is fit tested and passes the fit test. All of these provisions deal with the ability of the respirator to achieve a good face seal with a particular employee.

Good face fit is critical in assuring proper performance of respiratory protection. When an employee inhales through a respirator that does not fit properly, contaminated workplace air can enter the respirator through gaps and leaks in the seal between the face and the facepiece. OSHA is requiring the employer to provide each employee who must wear a respirator with one that fits. To do so, the employer will have to consider the facial sizes and characteristics in his or her workplace. It is not necessary for the employer to have respirators of different sizes of characteristics unless the employees need them. In other words, an employer may need only one or two styles and sizes. However, in workplaces where employees have different facial sizes and characteristics, obtaining proper respirator fit for each employee may require the fit testing of different mask sizes, possibly from several manufacturers. Proper respirator fit reduces inhalation leakage through the face-to-facepiece seal to a minimum.

Once a respirator has been selected based on its ability to achieve an adequate face-to-facepiece seal, the employee must be able to check that the respirator is properly seated and sealed to his or her face each time it is donned. The respirator, therefore, must be able to be fit checked by the employee. This is a procedure in which the employee covers the filter surface of the respirator and inhales (negative fit check) and exhales (positive fit check). If the respirator has an exhalation valve, this valve must be covered during the positive fit check. A respirator that is properly sealed will firmly adhere to the wearer's face upon inhalation due to the negative pressure created inside the mask. Upon exhalation, the mask should lift slightly off of the wearer's face to allow air to escape around the face seal. Employers should be aware that a problem could exist with fit checking some disposable negative pressure respirators. That is, it is difficult to cover the entire filter surface, thereby hindering the employee's ability to perform a proper fit check. At least one respirator manufacturer has developed a "fit-check cup" that covers the filter surface of their disposable respirator, thereby permitting the user to more easily perform a fit check. Reusable elastomeric facepiece respirators utilize filter cartridges that can be covered for performing a fit check.

CDC's first criteria, regarding filter efficiency, is addressed under paragraph (f)(3)(ii) of the standard. This provision requires the employer to select a respirator that will function effectively in the conditions of the work setting. In addition to meeting the criteria in paragraph (f)(3)(i) above, the respirator shall be, at a minimum, either a High Efficiency Particulate Air (HEPA) respirator selected from among those jointly approved as acceptable by the Mine Safety and Health Administration (MSHA) and by the National Institute for Occupational Safety and Health (NIOSH) under the provisions of 30 CFR part 11, or an N95 respirator certified by NIOSH under the provisions of 42 CFR part 84.

NIOSH and MSHA are the government agencies charged with testing and certifying respiratory protective devices. It has always been OSHA's policy that respiratory protection must be certified by these agencies before being deemed acceptable. Until recently, HEPA respirators were the only NIOSH certified negative pressure respirators that met the CDC's filter efficiency criteria. However, on July 10, 1995, NIOSH's original respirator certification procedures for air-purifying particulate respirators, 30 CFR part 11, were replaced by revised procedures, 42 CFR part 84 (Ex. 7-261). Under the new procedures, all nonpowered air-purifying particulate respirators are challenged with a 0.3 micron particle (the most penetrating size) at a flow rate of 85 liters per minute. At the conclusion of the test, those respirators that pass are placed into one of nine classes of filters (three levels of filter efficiency, with three categories of resistance to filter efficiency degradation). The three levels of filter efficiency are 99.97 %, 99 %, and 95 %. The three categories of resistance to filter efficiency degradation are labeled N (not resistant to oil), R (resistant to oil), and P (oil proof). Given these categories, a type N95 respirator would meet or exceed the filter efficiency performance criteria set forth in the CDC guidelines which state that a respirator appropriate for use in protecting against transmission of tuberculosis must be able to filter particles 1 micron in size in the unloaded state with a filter efficiency of ?95 %, given flow rates up to 50 liters per minute (Ex. 4B). The underlying reasoning for the acceptability of type N95 respirators is that their filter efficiency of >95 % for a 0.3 micron particle will exceed 95 % filtering efficiency for a particle three times as large (i.e., 1 micron). Also, the Agency assumes that oil aerosols are not likely to be found in the work settings covered by the standard, and therefore, that the use of a category N respirator would be sufficient. However, if oil aerosols are present, the employer would be expected to consider this when selecting the category of respirator to be used in his or her workplace.

OSHA is permitting the employer to select either a HEPA respirator certified under 30 CFR part 11 or a respirator certified under 42 CFR part 84, since particulate respirators certified under both of these regulations are currently on the market. HEPA respirators are the only nonpowered particulate respirators certified under 30 CFR part 11 that meet the CDC guidelines filtration criteria. However, applications for certification of nonpowered particulate respirators under 30 CFR part 11 are no longer being accepted by NIOSH. Therefore, dwindling stocks of HEPA respirators certified under that regulation will eventually lead to their unavailability, and employers will of necessity be selecting respirators from those approved under 42 CFR part 84.

Paragraph (f)(4)(i) states that the employer shall not permit any respirator that depends on a tight face-to-facepiece seal for effectiveness to be worn by employees having any conditions that prevent such a seal. Examples of these conditions include, but are not limited to, facial hair that comes between the sealing surface of the facepiece and the face or facial hair that interferes with valve function, absence of normally worn dentures, facial scars, or headgear that projects under the facepiece seal. Paragraph (f)(4)(ii) requires the employer to assure that each employee who wears corrective glasses or goggles wears them in such a manner that they do not interfere with the seal of the facepiece to the face of the wearer. Tight-fitting facepiece respirators rely on a good face-to-facepiece seal in order to achieve effective protection. Therefore, the employer must not allow employees to wear such respirators with conditions that prevent such a seal. Several studies support the prohibition of facial hair that comes between the sealing surface of the facepiece and the face (Exs. 7-243, 7-242, 7-182). A study by Skretvedt and Loschiavo found that bearded subjects wearing half-mask respirators had a median face seal leakage 246 times greater than clean shaven subjects. They go on to state:

Even though a number of bearded individuals did obtain fit factors above OSHA's minimum requirement for half-mask respirators, they all failed the qualitative fit test. No relationship was found between the length, shape, density and texture of beards and the amount of face seal leakage. Therefore, the only way to identify bearded negative-pressure respirator wearers obtaining fit factors above OSHA's minimum requirements would be by performing a quantitative fit test on them. However, even if quantitative fit tests are performed on all bearded individuals, another problem must be faced. The drop in the fit factor experienced when a beard is present is of such magnitude that no confidence can be placed in the protection the respirator will provide in the workplace or in future donnings. All respirator users experience variability from one donning to the next. This fit variability from donning to donning occurs due to changes in strap tension, positioning on the face, and a host of other variables. Donning-to-donning fit variability for bearded individuals will be even greater since additional variables will be introduced. A beard is a dynamically changing thing. The hair length constantly changes as well as the orientation of the hair in the sealing surface. Beards also accumulate moisture, natural oils, and debris from the workplace. Even though a percentage of bearded respirator wearers obtain fit factors slightly above OSHA's minimum requirements, the tremendous drop in fit factor resulting from the presence of a beard is such that the safety factor necessary to accommodate the variability of fit no longer exists. In summary, although bearded individuals may be able to achieve fit factors above OSHA's minimum requirements during a specific quantitative fit test, the drop in protection caused by a beard coupled with the large fit variability from donning to donning makes it quite likely that the individual will not obtain the minimum required protection in the workplace. (Ex. 7-243)

Therefore, while a bearded respirator wearer may be able to obtain a satisfactory fit on a particular occasion, one cannot assume that the individual can reliably be expected to achieve that same protection level each time the respirator is used. Beards grow and change daily. Each time a respirator is donned there is fit variability. Such variability in face seal is greatly increased for bearded workers. This large variability in fit means that a reliable seal cannot be reasonably expected. This provision should not be construed as a blanket prohibition on beards among respirator wearers. There are other types of respiratory equipment such as hoods, helmets and suits that can be worn by employees with beards, since they do not rely upon a tight facepiece fit. In addition, this provision refers to facial hair that interferes with the facepiece seal rather than simply growth of beard or sideburns. It is the interference with the facepiece seal that is the concern, not the presence of facial hair. Other conditions such as the absence of normally worn dentures, facial scarring and cosmetic surgery change the geometry of the face, thereby changing the ability of the respirator wearer to achieve a facepiece seal. Facepiece seal may also be compromised when headgear, temple pieces and nose pieces of glasses, the edges of goggles and so forth project underneath the respirator's sealing surface. Both of the above provisions are intended to eliminate or minimize conditions that jeopardize face-to-facepiece seal and could permit leakage of outside air into the facepiece.

Paragraph (f)(4)(iii) states that disposable respirators must be discarded when excessive resistance, physical damage, or any other condition renders the respirator unsuitable for use. It is not expected that the filter media of respiratory protective devices would become occluded with particulates in the work settings covered by this standard. However, if excessive resistance is noted, the respirator must be discarded. Also, such respirators must be structurally sound in order to provide a proper face seal and maintain their effectiveness. Whenever physical damage occurs (e.g., the respirator is crumpled or torn; the flexible face seal is damaged; a head strap is broken), effective functioning cannot be assured and the respirator must be replaced. In addition, other conditions may render the respirator unsuitable for use (e.g., the respirator may become contaminated with blood), thereby requiring discard.

In view of the types of activities carried out and the environmental conditions encountered in the work settings covered by this standard, OSHA is proposing to allow the multiple use of disposable respirators. However, this action should in no way be construed as setting a precedent for the use of disposable respirators in any other OSHA standards or in how OSHA views multiple use of disposable respirators in other work settings. OSHA requests comment on the approach taken in this proposal toward the reuse of disposable respirators.

Paragraph (f)(4)(iv) requires the employer to assure that each employee, upon donning a tight-fitting respirator, performs a facepiece fit check prior to entering a work area where respirators are required. In performing the fit check, the procedures in Appendix B or other procedures recommended by the respirator manufacturer that provide equivalent protection to the procedures in Appendix B must be used. This provision is supported by a recent study by Meyers et al. that concluded:

* * * for wearers of respirators that have been properly fit by a recognized fit test, conducting fit checks according to the manufacturer's instructions can be a useful tool for more consistently maintaining the quality of respirator donning. (Ex. 7-233)

The use of such seal checks are a way of helping to assure that attention is paid to obtaining an adequate facepiece seal each time a respirator is used.

The standard requires, under paragraph (f)(4)(v), that respirators be immediately repaired, or discarded and replaced when they are no longer in proper working condition. Examples of these changes in condition would be that a strap has broken, the respirator has lost its shape, or the face seal can no longer be maintained. As discussed above, respirators must be in good working condition in order to function effectively. Therefore, it is imperative that they not be used if they have been impaired in any way. The respirator manufacturers can supply replacement parts for damaged portions of their elastomeric respirators. Disposable respirators cannot be repaired and must be discarded when damaged.

Paragraph (f)(4)(vi) stipulates that the employer shall permit each employee to leave the respirator use area as soon as practical to: (A) change the filter elements or replace the respirator whenever the ability of the respirator to function effectively is compromised or the employee detects a change in breathing resistance; or (B) wash his or her face and respirator facepiece as necessary to prevent skin irritation associated with respirator use. This provision encourages and facilitates the proper use of respirators by employees by authorizing employees to take specific actions to assure the effective functioning of their respirators. This provision is consistent with requirements in other health standards (e.g., Lead, 29 CFR 1910.1025; Cadmium, 29 CFR 1910.1027).

Considering the health problems that may be exacerbated with respirator use and their associated detrimental effects on an employee, the proposal states in paragraph (f)(4)(vii) that each employee required to wear a respirator under this section shall be evaluated in accordance with paragraph (g), Medical Surveillance, of this section to determine whether any health conditions exist that could affect the employee's ability to wear a respirator. In addition, paragraph (f)(4)(viii) states that no employee shall be assigned a task requiring the use of a respirator if, based upon the employee's most recent evaluation, the physician or other licensed health care professional, as appropriate, determines that the employee will be unable to continue to function adequately while wearing a respirator. If the physician or other licensed health care professional, as appropriate, determines that the employee's job activities must be limited, or that the employee must be removed from the employee's current job because of the employee's inability to wear a respirator, the limitation or removal shall be in accordance with paragraph (g)(5)(iii) under Medical Removal Protection of this section.

Common health problems that could interfere with respirator use include claustrophobia (an intolerance of feeling enclosed and a subjective feeling of breathing difficulty), chronic rhinitis, nasal allergies that would necessitate frequent removal of the respirator to deal with nasal discharges, and chronic sinusitis. In addition, difficulties with the use of respirators may arise in employees with respiratory or cardiac diseases. Respiratory diseases include chronic obstructive pulmonary disease, emphysema, asthma, and moderate to severe pneumoconiosis. Cardiac or cardiorespiratory diseases that may affect respirator wear include any type of congestive heart disease, other ischemic heart diseases, and hypertension.

As discussed further under paragraph (g)(5)(iv), Medical Surveillance, of this section, employees who are removed from work due to the inability to wear a respirator are afforded certain medical removal protection relative to retention of earnings, seniority, rights and benefits. The Agency believes that these provisions will encourage all employees, including those experiencing difficulty with respirator use, to participate in the Medical Surveillance Program and will minimize an employee's fear of losing his or her job due to the possible inability to wear a respirator.

Paragraph (f)(5)(i) requires the employer to perform either quantitative or qualitative face fit tests in accordance with the procedures outlined in Appendix B of this section.

Quantitative fit testing is an assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the facepiece. One method of accomplishing this assessment utilizes a procedure whereby the level of penetration of a test agent of a known concentration is measured inside the facepiece of the respirator. In this quantitative fit test procedure, the respirator is worn in a stable test atmosphere containing a suitable challenge agent. The adequacy of fit is determined by measuring the actual levels of the challenge agent, both outside and inside the facepiece of the respirator. This provides a quantitative assessment of the fit (the fit factor). Fit testing allows the employer to continue testing different facepieces until a properly fitting respirator is identified and selected for the employee. Quantitative fit testing requires the use of moderately sophisticated testing equipment and is more expensive to perform than qualitative fit testing, which may reduce its availability in some work sites. Also, testing services may not be available in all parts of the country to provide quantitative fit testing services for small businesses.

Qualitative fit testing does not provide a numerical measure of the quality of the fit but simply determines whether a respirator fits or not. The outcome of the test is simply a pass or fail result. Qualitative fit testing involves the detection of a gas, vapor, or aerosol challenge agent through subjective means such as odor, taste, or nasal irritation. If the challenge agent's presence is detected, the respirator fit is considered to be inadequate. Qualitative fit testing is more subjective than quantitative testing because it depends on the individual's ability to detect the test agent.

OSHA believes that while quantitative fit testing has some advantages, qualitative fit testing conducted in accordance with the protocols described in Appendix B of this section can generally accomplish the intent of the standard, which is to assure that each employee is assigned and wears a respirator that provides a proper fit.

Paragraph (f)(5)(ii) states that the employer shall assure that each employee who must wear tight-fitting respirator passes a fit test: (A) at the time of initial fitting; (B) whenever changes occur in the employee's facial characteristics that affect the fit of the respirator; (C) whenever a different size or make of respirator is used; and (D) at least annually thereafter unless the annual determination required under paragraph (g)(3)(ii)(A), Medical Surveillance, indicates that the annual fit test of the employee is not necessary. This frequency of fit testing is necessary to assure that factors that may affect the proper fit of a respirator are detected and necessary adjustments are performed to assure the integrity of the faceseal. For example, the fit of respirators is not standardized among manufacturers. Fit testing would be required, therefore, whenever a different size or make of respirator is used. In addition, a change in an employee's facial structure can compromise a respirator's faceseal. Examples of such changes include loss of weight, cosmetic surgery, facial scarring, and the installation of dentures or the absence of dentures that are normally worn by the individual. Therefore, fit testing is required when any facial changes, such as those mentioned above, occur.

Requiring annual fit testing, unless the annual determination by the physician or other licensed health care professional indicates that the annual fit test is not necessary, assures that factors that could affect respirator fit are detected and the employee's respirator is adjusted or replaced as necessary. It is OSHA's intent in this provision that each employee be evaluated annually for respirator fit. This can be accomplished through either an actual fit test or through a person-to-person evaluation consisting of a questionnaire and personal observation by the evaluator carried out under paragraph (g)(3)(ii)(A), Medical Surveillance, of this section. It should be noted that an annual determination of respirator fit is required, either through fit testing or the person-to-person evaluation. The employer may use the determination of the need for the annual fit test in lieu of an annual fit test if that determination indicates that a fit test is not necessary.

One of the criteria that must be satisfied when selecting respirators is a faceseal leakage of 10 % or less. OSHA considers any respirator that passes a qualitative fit test to meet this criteria. However, quantitative fit testing necessitates that a particular numerical value be achieved. Therefore, paragraph (f)(5)(iii) requires that when quantitative fit testing is performed, the employer shall not permit an employee to wear a tight-fitting respirator unless a minimum fit factor of one hundred (100) is obtained in the test chamber. This value corresponds to a faceseal leakage of 10 % or less.

In order to assure that continuing protection is achieved by reusable and powered air purifying respiratory protective devices, it is necessary to establish and implement proper maintenance and care procedures. A lax attitude toward this part of the respiratory protection program will negate successful selection and fit because the devices will not deliver the assumed protection unless they are kept in proper working order. A basic program for assuring proper respirator function would contain procedures for cleaning, inspection, repair, and replacement of respirators used in the workplace.

Paragraph (f)(6)(i) requires that the employer clean and disinfect the respirators using the manufacturer's recommended procedures at the following intervals: (A) as necessary for respirators issued for the exclusive use of an employee; and (B) after each use for respirators issued to more than one employee. Respirators that are not cleaned and disinfected can cause skin irritation and dermatitis. When more than one employee uses the same respirator, cleaning and disinfecting after each use provides the additional benefit of minimizing the respirator's role as a vehicle for spreading infections (e.g., skin, respiratory) between employees.

In order to assure continued respirator reliability, they must be inspected on a regular basis. Therefore, paragraph (f)(6)(ii) requires that respirators be inspected before each use and during cleaning after each use. As stipulated in paragraph (f)(6)(iii), such inspections must include: (A) a check of respirator function, tightness of connections and condition of the facepiece, head straps, valves, connecting tube, and cartridges, canisters, or filters; and (B) a check of the rubber or elastomer parts for pliability and signs of deterioration. In this way, the employer can assure that the respirator is functioning as intended, is able to be adjusted by the user, will not allow leakage through cracks or breaks in the respirator, and is pliable enough to achieve a proper faceseal.

The standard also contains provisions regarding those respirators that are found to be deficient upon inspection. Paragraph (f)(6)(iv) states that respirators that fail to pass inspection must be removed from service and repaired or adjusted in accordance with the following: (A) repairs or adjustments to respirators are only to be made with NIOSH-approved parts designed for the respirator by the respirator manufacturer and by persons appropriately trained to perform such operations; (B) only repairs of the type and extent covered by the manufacturer's recommendations may be performed; and (C) reducing or admission valves or regulators shall be returned to the manufacturer or given to an appropriately trained technician for adjustment or repair. It is self-evident that repairs to respirators should only be performed by trained individuals, using parts designed for the specific respirator under repair (not all respirator designs are identical), and that the individual should not attempt repairs that he or she is not qualified to undertake or which are not recommended by the manufacturer.

Another important aspect of assuring appropriate respirator function is proper storage. Therefore, paragraph (f)(6)(v) stipulates that the employer assure that respirators are stored in a manner that protects them from contamination, damage, dust, sunlight, extreme temperatures, excessive moisture, damaging chemicals and that prevents deformation of the facepiece or exhalation valve. Proper storage, of both new respirators and those already in service, assists in maintaining appropriate respirator function by minimizing conditions that may cause deterioration of the respirator or filter, interfere with filter efficiency, change faceseal geometry, and prevent sealing of valves against inhalation of contaminated air.

As discussed previously, OSHA accepts those respirators certified by MSHA and NIOSH. Therefore, paragraph (f)(7)(i) requires that filters, cartridges, and canisters used in the workplace are properly labeled and color-coded with the NIOSH approval label as required by 30 CFR part 11 or 42 CFR part 84, whichever is applicable, before they are placed into service. The employer must assure that the existing NIOSH approval label on a filter, cartridge, or canister is not intentionally removed, obscured, or defaced while it is in service in the workplace, as required by paragraph (f)(7)(ii) of this section.

Paragraph (f)(8) requires the employer to review the overall respiratory protection program at least annually, and conduct inspections of the workplace as necessary to assure that the provisions of the program are being properly implemented for all affected employees. The reason an employer must conduct an annual review and inspections as necessary is because respirators are utilized as supplemental and, in some instances, sole protection to prevent transmission of infectious TB. Therefore, it is of primary importance to assure proper implementation of the program. The review of the program must include an assessment of each element required under paragraph (f)(2) of this section. Once the respiratory protection program is implemented, the employer retains responsibility for detecting and addressing problems that arise. While the written respiratory protection program is required to be reviewed and updated under paragraph (f)(2)(iii) of the standard, the overall review requires that the employer evaluate actual implementation in the workplace. Consequently, this provision stipulates inspections of the workplace and an assessment of each element required under paragraph (f)(2) of this section to assure proper implementation of the program.

OSHA believes that the proposed provisions regarding respirators are both appropriate and justified. OSHA seeks comments and data on all aspects of the proposed respirator requirements.

Paragraph (g) Medical Surveillance

(1) General

The purpose of this section is early detection and prevention of disease through employee medical histories and physical examinations, TB skin testing, medical management and follow-up of exposure incidents and skin test conversions, and medical removal of employees with suspected or confirmed infectious TB. These requirements are designed to ensure early detection of TB infections and disease by providing appropriate medical examinations to enable identification of infection or disease and to minimize the spread of TB to other employees in the workplace. Additionally, there are requirements in this section to assure that employees required to wear respiratory protection are evaluated to determine their ability to wear a respirator and advised about the need for annual fit testing. The needs of employees who have health conditions that might require special attention are also addressed (e.g., anergy testing, more frequent screening, or further medical examinations to diagnose TB).

Paragraph (g)(1) calls for medical surveillance to be provided for each employee who has occupational exposure, as defined in this standard. Occupational exposure may result in TB infection and the subsequent development of TB disease. Paragraphs (c)(1)(i, ii), (exposure determination) require the employer to identify employees with occupational exposure in the facility. These employees must be offered medical surveillance.

OSHA believes that early detection and management of exposed employees helps prevent severe illness and death. According to CDC's 1994 edition of the Core Curriculum on Tuberculosis (Ex. 7-93), approximately ten percent of the persons infected will develop active TB disease at some point in their lives (Exs. 4B, 7-50, 7-93). Five per cent of those infected develop disease within the first two years following infection and another five percent develop disease later in their lives. Immunosuppressed persons are at a considerably greater risk of developing active disease following a TB infection. For example, individuals infected with HIV and TB have been estimated to have a 8-10 % risk per year of developing active disease (Ex. 7-50). However, according to the American Thoracic Society:

Clinical trials have shown that daily isoniazid preventive therapy for 12 months will reduce the risk of developing tuberculosis in infected persons by about 70 percent and in over 90 percent of patients who are compliant in taking the medications. (Ex. 5-80)

Most infected people have a positive reaction to the TB skin test within 2-10 weeks after exposure. Consequently, early detection of newly infected workers is critical as it permits early initiation of appropriate therapy and results in a decrease in morbidity and mortality.

Paragraph (g)(1)(ii) requires that information about the signs and symptoms of pulmonary tuberculosis disease, a medical history, a physical examination, TB skin testing, medical management and follow-up, and if indicated, other related tests and procedures and medical removal protection if the employee develops infectious TB, be provided to each employee in work settings described in paragraph (a) Scope who sustains an "exposure incident." This provision is applicable when the employee has not been categorized as having occupational exposure in the employer's Exposure Control Plan. OSHA recognizes that there may be times when employees who are not "reasonably anticipated" to have occupational exposure to TB may be exposed, (e.g., if engineering controls break down or an individual with infectious tuberculosis is unidentified during intake procedures). Employees exposed under such circumstances incur the risk of TB infection and subsequent disease (Ex. 7-93) as a result of their work duties. OSHA includes this provision so that these employees are provided protection.

Paragraph (g)(1)(iii)(A) requires the employer to provide all medical surveillance at no cost to the employee. This is consistent with OSHA policy. Providing services at no cost to the employee is an important factor in successful workplace health and safety programs because it encourages employee participation in medical surveillance programs.

Paragraph (g)(1)(iii)(B) requires that all medical surveillance be provided at a reasonable time and place for the employee. Convenience of these procedures increases the likelihood of employee participation in the program. This helps assure that employees receive the full benefits provided by the standard. OSHA recognizes the need for this provision and has included it in other standards (e.g., Ethylene Oxide, 29 CFR 1910.1047; Asbestos, 29 CFR 1910.1001; and Bloodborne Pathogens 29 CFR 1910.1030).

Paragraph (g)(1)(iii)(C) states that all medical surveillance is required to be performed by or under the supervision of a physician or other licensed health care professional, as appropriate. OSHA has included in paragraph (j) Definitions, a description of the licensed health care professional. Such an individual is a physician or other health care professional who holds a license enabling her or him to independently provide or be delegated the responsibilities to provide some or all of the health care services required by this paragraph. In several states, nurse practitioners may be licensed to independently perform or supervise the evaluations and procedures required by this paragraph. In such cases, the requirements of this standard can be accomplished by those practitioners. In addition, where registered nurses are licensed to perform or supervise some of the requirements of this standard, those requirements can be accomplished by those professionals.

Paragraph (g)(1)(iii)(D) requires that medical surveillance procedures be provided according to recommendations of the CDC, current at the time these procedures are performed, except as specified by this paragraph (g). In other words, employers must comply with paragraph (g), and with the most current CDC recommendations in providing medical surveillance. OSHA has set forth what an employer must do to prevent or minimize occupational exposure in the employer's workplace. However, CDC, an agency of the U.S. Public Health Service (USPHS), follows the epidemiology of M. tuberculosis and periodically revises and updates its guidelines and recommendations to reflect changes in the diagnosis and treatment of TB. OSHA believes that in addition to meeting the requirements of paragraph (g), it is appropriate to follow CDC recommendations, which address screening, medical evaluations, TB skin test procedures and follow-up (e.g., the administration and interpretation of skin tests).

OSHA recognizes the dynamic nature of medical knowledge relating to tuberculosis and notes that CDC recommendations current at the time of the standard's publication may differ from recommendations at some future time when an employee evaluation takes place. Knowledge about tuberculosis is expanding. For example, the medical response to HIV/AIDS as related to tuberculosis continues to evolve. These are the reasons why OSHA has not simply required the employer to comply with a particular CDC guideline. OSHA believes that incorporating the CDC recommendations into the standard by reference enhances the quality of medical surveillance. This assures that employees are provided the most current and effective evaluation and treatment. Furthermore, the CDC recommendations provide consistency with regularly updated medical science and health care practice. A similar provision was included in the Bloodborne Pathogens standard 29 CFR 1910.1030 and met with widespread acceptance from the regulated community. The CDC recommendations cover the specific details of the medical protocols.

Paragraph (g)(1)(iv) requires that all laboratory tests be performed by an accredited laboratory. Accreditation by a national accrediting body or its state equivalent means that the laboratory has participated in a recognized quality assurance program. (For an explanation of "accredited laboratory" see paragraph (j) Definitions below). This accreditation process is required to assure a measure of quality control so that employees receive accurate information concerning their laboratory tests. The accreditation requirement assures long-term stability and consistency among laboratory test procedures and interpretations of results. OSHA recognizes the need for this requirement and has included it in other standards (e.g., Benzene, 29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030).

(2) Explanation of Terms

This paragraph explains the terms used in paragraph (g) Medical Surveillance. Paragraphs (g)(2)(i) to (g)(2)(vii) include explanations of the "medical history", the "physical examination (with emphasis on the pulmonary system, signs and symptoms of infectious tuberculosis, and factors affecting immunocompetence)", "TB skin testing", the "face-to-face determination of ability to wear a respirator and need to be re-fit tested", "medical management and follow-up", "other related procedures or tests determined to be necessary", and "Medical Removal Protection". The applications section, paragraph (g)(3), describes what must be provided and at what time.

Paragraph (g)(2)(i) describes a medical history, during which the examiner questions the employee in order to gather information on the employee's pulmonary system, TB exposure, vaccination, testing and disease status and factors affecting immunocompetence. A medical history questionnaire may be used as a starting point for this discussion. OSHA believes that a medical history is essential for interpreting the TB skin test results, which are also required by this paragraph (g). The CDC Core Curriculum states:

TB skin testing is a useful tool, but is not perfect. Several factors can affect the skin test reaction: for example, infection with mycobacteria other than M. tuberculosis and vaccination with BCG. These factors can lead to false-positive reactions * * * Other factors, such as anergy, can lead to false-negative reactions. (Ex. 7-93).

Therefore, the medical history is used to assist in interpreting the TB skin test results. The medical history also provides information regarding the employee's potential for increased risk if exposed to tuberculosis. Based on this information, discussions between the employee and the examiner regarding the employee's increased risk can assist the employee in decision-making.

Paragraph (g)(2)(ii) describes the physical examination. The physical examination is to emphasize the pulmonary system, signs and symptoms of active TB disease, and factors affecting immunocompetence. Such an examination assists the examiner in detecting evidence of active disease (e.g., rales), differentiating TB disease from other causes of cough or other signs/symptoms associated with TB disease, and ascertaining whether signs are present that are compatible with an immunocompromising health condition. The physical examination is also required when an employee has signs or symptoms of TB or after a TB skin test conversion and at other times, if indicated.

That the pulmonary system is emphasized in both the medical history and physical examination assures that the employee is evaluated with specific attention to the most common site of infectious TB. Although extrapulmonary tuberculosis can occur (e.g., in bone, meninges of the brain, and draining abscesses), it is not usually a source of infection for others. The language "with emphasis on the pulmonary system" is used to indicate that while the history and physical examinations evaluate the health of the patient as a whole, particular emphasis should be placed on the pulmonary system.

Paragraph (g)(2)(iii) explains the required TB skin testing. TB skin testing is the cornerstone for early detection of TB transmission among exposed workers. The American Thoracic Society notes that:

Although currently available TB skin tests are substantially less than 100 % sensitive and specific for detection of infection with M. tuberculosis, no better diagnostic methods have yet been devised. (Ex. 5-4)

The TB skin test is an important tool that is useful in identifying employees who may be eligible for appropriate, early treatment; initiating contact investigations; and evaluating the effectiveness of the facility's control program. The requirement for TB skin testing is supported by AHA (Exs. 7-61, 7-29 ), APIC (Ex. 7-30), AIHA (Ex. 7-170) and the CDC 1994 Core Curriculum which states, "TB screening should be done in groups for which rates of TB are substantially higher than the general population." [Ex. 7-93]. In this document, CDC specifically mentions screening for health care workers, staff of long term care facilities, correctional facilities, hospices, drug treatment centers, and nursing homes.

Paragraph (g)(2)(iii) describes the requirement for TB skin testing. TB skin testing, which only applies to employees whose TB skin test status is not known to be positive, includes anergy testing if indicated, and consists of an initial 2-step protocol for each employee who has not been previously skin tested and/or for whom a negative test in the past 12 months cannot be documented. If the employer has documentation that the employee has had a negative TB skin test within the past 12 months, that test may be used to fulfill the skin testing portion of the initial medical surveillance requirements. For example, if an employer has a new or existing employee for whom: (1) a TB skin test has not previously been performed, or (2) a negative skin test result within the past 12 months that cannot be documented, the employer is required to provide an initial two-step skin test for the employee. Conversely, if the employer can document a negative skin test result from a test performed on the employee within the past 12 months, that test can be used to fulfill the initial skin testing requirement of this section. Subsequent periodic retesting of the employee is to be performed in accordance with paragraph (g)(3), as discussed below.

It is important for the employer to determine the current TB skin test status of employees prior to their initial assignment to a job with occupational exposure. This "baseline" status can then be used to evaluate changes in the employees' TB skin test.

In their 1992 guidelines, the American Thoracic Society recommended the following:

Individuals at high risk for TB should have a TB skin test at least once to assess their need for preventive therapy and to alert the health care providers of those with positive skin tests of this medical problem. In institutional settings, baseline information on the TB skin test status of staff and residents is a means of identifying candidates for preventive therapy as well as determining whether transmission of TB is occurring in the facility. For this reason, TB skin testing upon employment or upon entry should be mandatory for staff and residents * * * (Ex. 5-80)

Previous BCG vaccination is not a contraindication for skin testing. In its 1994 guidelines, the CDC states:

During the pre-employment physical or when applying for hospital privileges, HCWs who have the potential for exposure to M. tuberculosis [sic], including those with a history of BCG vaccination, should have baseline PPD skin testing performed * * *

BCG vaccination may produce a PPD reaction that cannot be distinguished reliably from a reaction caused by infection with M. tuberculosis. For a person who was vaccinated with BCG, the probability that a PPD test reaction results from infection with M. tuberculosis increases (a) as the size of the reaction increases, (b) when the person is a contact of a person with TB, (c) when the person's country of origin has a high prevalence of TB, and (d) as the length of time between vaccination and PPD testing increases. For example, a PPD test reaction of >10 mm probably can be attributed to M. tuberculosis in an adult who was vaccinated with BCG as a child and who is from a country with a high prevalence of TB. (Ex. 4B)

CDC does not state that BCG vaccination negates the need for baseline and periodic skin testing but does state that skin tests on vaccinated individuals need to be interpreted carefully. OSHA's proposed rule is consistent with the CDC Guidelines on this point. PPD testing is thus not contraindicated for BCG vaccinated employees; however, such prior vaccination does mean that other factors, such as the age of the employee and the extent of induration, must be considered in interpreting the results.

The purpose of performing a two-step test is to correctly identify the baseline TB skin test status of those employees who are infected with TB but whose sensitivity to the tuberculin testing material may have waned over the years. This procedure enhances the proper interpretation of subsequent positive TB skin test results and is based upon current CDC and American Thoracic Society recommendations (Exs. 5-80, 6-15, 7-52, 7-93, 7-169).

Two-step testing requires an employee to be tested initially and, if the test results are negative, to be tested again within 1-3 weeks. This second test stimulates or "boosts" the body's response to the testing material and results in a more valid reaction. For example, an employee who has not been recently tested but who is infected with TB from an earlier exposure may fail to respond to this current test because his or her immune response has waned over time. However, a second test of this employee will produce a positive TB skin test that more accurately reflects his or her true TB skin test status. Thus, the initial use of a two-step testing procedure ensures that the baseline TB skin test is an accurate reflection of the employee's TB status and will reduce the likelihood of misinterpreting a "boosted" reaction on subsequent tests as a conversion. Two-step testing is also appropriate for individuals who have been BCG vaccinated, since these individuals can exhibit a boosted reaction. Therefore, two-step testing of BCG vaccinated individuals can be used to determine their baseline status, although the skin test results must be interpreted in light of their previous BCG vaccination.

The two-step testing procedure does not identify those persons who are truly anergic and, therefore, are not capable of mounting a typical immune response to the test material. Evaluation of adequate immune response, when determined to be necessary by the physician or other licensed health care professional, as appropriate, is determined through anergy testing, and this is provided for in the explanation of TB skin testing in paragraph (g)(2)(iii).

The CDC recommendations are the guiding documents for TB skin test protocols. By referring the employer to these recommendations in Paragraph (g)(1)(iii)(D), OSHA allows for future changes in protocols and procedures that result from continuing research. Consistent with the CDC guidelines (Exs. 3-33, 3-35, 3-32, 6-15), the American Thoracic Society recommends:

The Mantoux test with 5 Tuberculin Units (TU) of PPD may be used as a diagnostic aid to detect tuberculous infection and to determine the prevalence of infection in groups of people. (Ex. 5-4)

Proper administration of a TB skin test results in a reaction described as a classic example of a delayed (cellular) hypersensitivity reaction. This reaction indicates infection with mycobacterium, most commonly M. tuberculosis. The reaction characteristically begins in 5-6 hours, is maximal at 48-72 hours, and subsides over a period of days (Ex. 5-4).

Proper administration and interpretation of the test is critical and can be complex. In 1990, the American Thoracic Society revised the criteria for interpreting the TB skin test (Ex. 5-4). Information such as the health status of the tested employee, history of BCG vaccination, recent close contact with persons with active TB, chest x-ray results, and other factors must be considered when interpreting the TB skin test results. CDC has established criteria for a TB skin test conversion; that is, when an employee's TB skin test results change from negative to positive, indicating a recent TB infection (Ex. 4-B).

Because of the complexity in properly administering and interpreting TB skin tests, it is essential that only trained individuals perform this function. For this reason, TB skin testing is to be administered and interpreted by or under the supervision of a physician or other licensed health care professional as appropriate and according to CDC recommendations. This language allows employers to chose from a variety of health care professionals who can administer and interpret TB skin tests. OSHA is aware that in some worksites, employees have been allowed to read and interpret their own skin test results. A surveillance system that allows self-reading and interpretation of TB skin tests can be problematic. With regard to interpretation of TB skin test results, the American Thoracic Society states:

Intelligent interpretation of skin test results requires a knowledge of the antigen used (tuberculin), the immunologic basis for the reaction to the antigen, the technique(s) of administering and reading the test, and the results of epidemiologic and clinical experience with the test. (Ex. 5-4)

In its 1994 Core Curriculum on Tuberculosis (Ex. 7-93), CDC describes the complexities of interpreting the induration resulting from TB skin testing. A number of factors can affect the size of a TB skin test induration relative to whether or not the test should be interpreted as being positive. For example, induration of 5 mm or more is classified as positive for persons with known or suspected HIV infection, while an induration must be 10 mm to be classified as positive in persons who are foreign-born in high prevalence countries. An induration of 15 mm or more is classified as positive in certain other situations. In addition, TB skin testing can result in both false positive and false negative results.

Clearly, interpreting TB skin test results requires professional expertise and must be performed by or under the supervision of a physician or other licensed health care professional, as appropriate, by an individual with training and experience in performing the test and interpreting the result. Proper use of the TB skin test as a medical surveillance tool will require two visits to the health care professional: one to receive the test and one to read/interpret the test results. However, considering the critical importance of this element, OSHA believes that allowing employees to read and interpret their own tests or allowing their peers to do so (unless they meet the criteria discussed above) compromises the quality and accuracy of the testing procedure.
Paragraph (g)(2)(iv) describes the determination of each employee's ability to wear a respirator and of his or her need for re-fit testing for employees required to wear a respirator. This face-to-face determination includes a verbal exchange between the employee and the examiner regarding the employee's health factors such as illness or injuries, that may impact his or her ability to wear a respirator (e.g. vascular or heart disease, asthma, claustrophobia, facial structure defects, certain skin conditions, etc.) (Ex.7-64). Based on this history and the observation of the employee, the need for further testing or physical examinations for the ability to wear a respirator can be determined. In addition, assessment of the need for re-fit testing is to be performed, which assures that the examiner consider whether re-fit testing is needed. OSHA has included a note stating that the determination of the need for re-fit testing may only be performed after the required initial fit test of the employee and cannot be used in lieu of any other required fit tests, as, for example, when a different size or make of respirator is used.

Paragraph (g)(2)(v) explains that medical management and follow-up include diagnosis, and, where appropriate, prophylaxis and treatment related to TB infection and disease. The employer must provide medical management and follow-up for occupationally exposed employees with skin test conversions [paragraph (g)(3)(i)(D)], or those who undergo an exposure incident whether or not they are categorized as occupationally exposed [paragraphs (g)(1)(ii) and (g)(3)(i)(C)]. In addition, any time an occupationally exposed employee develops signs and symptoms of infectious tuberculosis, medical management and follow-up are required [paragraph (g)(3)(i)(B)]. John E. McGowan addressed follow-up in the 1995 article entitled "Nosocomial Tuberculosis: New Progress in Control and Prevention," published in Clinical Infectious Diseases. He states,

If the PPD skin testing program for health care workers is to be useful, several steps are crucial. * * * The institution also must make sure that the occupational health service undertakes careful follow-up of workers found to have positive TB skin tests or tuberculosis disease. This follow-up should include counseling, careful monitoring of therapy (when prescribed) until its completion and evaluation of fitness to return to work. (Ex. 7-248).

Paragraph (g)(2)(vi) explains that other related tests and procedures are any TB-related tests and procedures determined to be necessary by the physician or other licensed health care professional, as appropriate. These procedures or tests could include chest radiographs, sputum smears, or other testing determined to be necessary to make an assessment, a diagnosis, or medically manage the employee. An example of a program that integrates testing and examinations was given at the 1994 meeting of the Society for Occupational and Environmental Health, by Carol Murdzak who presented the University of Manitoba's Medical Surveillance program. Her presentation, entitled "Conducting a Medical Surveillance Program to Prevent and Control Transmission of TB in a Health Care Institution" demonstrates the use of skin testing and general review of health status for employee surveillance. Results of TB skin testing and the review of health status determine the need for chest x-ray and further medical evaluation in this program (Ex.7-169).

(3) Application

Medical examinations in the form of medical histories, physical examinations, TB skin testing and other related tests and procedures are necessary in order to promptly identify and treat employees with infectious tuberculosis.

Paragraph (g)(3), Application, specifies what an employer must provide. In each situation set forth in paragraph (g)(3), the employer must provide medical examinations, tests and procedures as specified. Some of the provisions are offered only "if indicated," which means that the physician or other licensed health care professional, as appropriate, has determined that further tests or procedures are needed. For example, an employee who has no history of illness or being immunocompromised and whose TB skin test is negative at the time of initial assignment is not required to be offered a physical examination unless the examiner determines that a physical examination is indicated. However, if at the time of annual skin test, the employee has a skin test conversion, a physical examination is required.

Paragraph (g)(3)(i)(A) requires that, before the time an employee is initially assigned to a job with occupational exposure (or within 60 days from the effective date of the standard for employees already assigned to jobs with occupational exposure), the employee be provided with a medical history, TB skin testing, and, if indicated, a physical examination and other related tests and procedures.

OSHA requires the initial medical history to assist in assessing the employee's health. This information will provide a baseline health status that can be used to evaluate (1) whether the employee has a pre-existing condition that may be exacerbated by occupational exposure to TB and (2) any future health conditions that may arise that are relevant to occupational exposure to TB.

OSHA does not believe that an initial physical examination for all occupationally exposed employees is necessarily warranted. However, the Agency does believe that a physical examination, if determined to be indicated by the examiner based on the medical history and TB skin test results, is useful and effective.

The note to paragraph (g)(3)(i)(A) specifies that if an employee has had a medical examination within the twelve (12) months preceding the effective date of the standard and the employer has documentation of that examination, only the medical surveillance provisions required by the standard that were not included in the examination need to be provided. The Agency realizes that employees may have received at least some of the elements of the required medical surveillance provisions shortly before the effective date of the standard. In these situations, a full TB examination would not need to be repeated.

In addition, the proposed standard allows the baseline TB skin testing status of an employee to be established by documentation of a TB skin test that was administered within the previous 12 months. For example, if an employee has a written record of a TB skin test within the last 12 months, that information can be used to document the employee's baseline TB skin test status and another TB skin test at the time of the initial medical examination is not necessary. When utilizing results from a previous medical examination and skin test to fulfill the initial medical surveillance requirements, the employer must use the date(s) of the previous medical exam and skin test to determine the date(s) of the employee's next medical examination and skin test. In no case shall the interval between the previous examination and skin test and the next examination and skin test exceed 12 months. These provisions are designed to avoid unnecessary testing of employees and do not compromise the quality of the medical surveillance.

Information (e.g., medical history) obtained from a medical examination in the past 12 months is unlikely to change within this span of time. However, this may not be the case with regard to previous skin testing results. While OSHA is proposing to accept a skin test performed within the past 12 months as a substitute for performing an initial baseline skin test, an employer utilizing a new employee's negative skin testing result obtained more than 3 months prior to beginning the new job may be uncertain as to the source and time of infection if the employee tests positive at his or her next skin test. More specifically, conversion normally occurs within 3 months of infection. Therefore, an employee would have been negative at his or her last skin test, e.g., 7 months previously, and have been infected just after the skin test and subsequently converted. In such a case, an employer may rely on the previous negative skin test as the baseline does not need to test the new employee until 5 months later (i.e., annual skin test frequency), at which time the employee would test positive and be identified as a converter. In this situation, the new employer would not be able to determine if the employee's conversion had occurred as a result of exposure occurring previous to hire or from exposure in his or her current work setting. Regardless of the source of the conversions, the employer would be required by the standard to initiate medical management and a follow-up investigation, which might also entail skin testing other employees in the worksite to determine if other conversions had taken place, a step that would not be necessary if the employee had been correctly identified as positive upon entry into the workplace. In view of this, employers may choose to perform an initial baseline skin test on each new employee before the employee enters the work setting.

Once an employee is on the job, paragraph (g)(3)(i)(A) requires employers to periodically retest employees who have negative TB skin tests in order to identify those employees whose skin test status changes, indicating that they have been infected. Because the baseline TB skin test provides only a "snapshot" of the TB skin test status of the employee and because exposure and subsequent infection can occur at any time, periodic testing is necessary. The American Thoracic Society recommends:

* * * follow-up skin-testing should be conducted on at least an annual basis among the staffs of TB clinics, health care facilities caring for patients with HIV infection, mycobacteriology laboratories, shelters for the homeless, nursing homes, substance-abuse treatment centers, dialysis units, and correctional institutions. (Ex. 5-80)

When TB exposure results in infection, early identification allows employees to have options regarding prophylactic treatment, thereby reducing the likelihood that the infection will progress to disease.

OSHA recognizes the importance of periodic testing to monitor the status of employee's skin test results. In their 1994 Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Facilities, the CDC recommends that the frequency of PPD skin testing of employees be based upon the individual facility's risk assessment in conjunction with the criteria put forth by the CDC (Ex. 4B). For situations that meet certain CDC criteria, CDC recommends that employees receive a repeat TB skin test every 3 months, six months or annually, depending upon the risk assessment.

OSHA's proposed standard does not require a risk assessment of the type described by CDC and would extend coverage to worksites other than "health-care facilities" as described in the CDC document (Ex. 4B). Consequently, OSHA is proposing that repeat TB skin test be performed every 6 months or annually, depending upon the exposure determination. This testing frequency is expected to be both practical and effective in early identification of skin test conversions in the various worksites described in the Scope. The requirements for more frequent TB skin tests (e.g., 3 months after an exposure incident, or if deemed necessary by a licensed health care professional) ensures that employees' health is not compromised.

An exemption to this annual testing is permitted for an employer who can demonstrate that his or her facility or work setting: (1) Does not admit or provide medical services to individuals with suspected or confirmed infectious TB, (2) has had no cases of confirmed infectious TB in the past 12 months, and (3) is located in a county that, in the past two years, has had 0 cases of confirmed infectious TB reported in one year and fewer than 6 cases of confirmed infectious TB reported in the other year. In these settings only a baseline TB skin test is required. This is discussed earlier under paragraph b, application.

Paragraph (g)(3)(i)(B) requires that, when an employee has signs or symptoms of TB, either observed or self-reported, the employee be provided a medical history, physical examination, TB skin testing, medical management and follow-up, and other related tests and procedures determined to be necessary. CDC states that the presence of signs or symptoms of tuberculosis in the employee requires prompt medical evaluation (Ex. 7-52, 7-93), and such evaluation provides an opportunity for initiating drug therapy. Furthermore, identifying those with infectious pulmonary TB disease enables the employer to remove them from the workplace, preventing exposure of other employees.

Paragraph (g)(3)(i)(C) requires that when an employee incurs an exposure incident, a medical history, TB skin testing, medical management and follow-up, and, if indicated, a physical examination and other related tests and procedures be provided. Evaluation and follow-up after each exposure incident help detect any resultant infections, as well as prevent infection in other employees, benefitting the health of all employees.

Following exposure, infected workers will usually develop a positive response to a TB skin test (Exs. 7-50, 7-93, 5-4). In certain cases, workers may also display signs or symptoms compatible with tuberculosis disease such as complaints of persistent cough (over 3 weeks in duration), bloody sputum, night sweats, weight loss, loss of appetite or fever. Use of the TB skin test has been recognized as a tool in the early identification of infection and for disease surveillance and follow-up. In paragraph (g)(3)(i)(C), the proposed standard also requires employers to provide testing for employees as soon as feasible after an exposure incident, unless a negative TB skin test has been documented within the preceding 3 months. If this baseline skin test is negative, another TB skin test shall be repeated 3 months after the exposure incident.

In order to accurately determine if an exposure incident has resulted in infection, the employer must first know the baseline skin test status of the affected employee(s) at the time of the exposure incident. Typically, skin test conversion can be documented approximately 2-10 weeks following infection (Ex. 7-52). Consequently, it can be reasonably assumed that a negative TB skin test within the three months prior to the incident is sufficiently indicative of the employee's status at the time of the exposure incident.

For those employees who do not have a documented negative skin test within the past three months, the employer must determine their TB skin test status as soon as feasible after the exposure incident. The requirement of "as soon as feasible" in the provision puts the employer under the obligation of performing the TB skin test quickly, i.e., before infection resulting from the exposure would be manifested as a conversion. This assures that a true indication of the employee's skin test status at the time of the incident is obtained.

The purpose of the initial TB skin test following an exposure incident is to establish the TB skin test status of the employee(s) at the time of the incident. From this baseline, changes in TB skin test status can be identified. This initial test would not detect infection resulting from the exposure, since there would not have been sufficient time for conversion to occur. Hence, the employer is required to provide a repeat TB skin test three months after the exposure incident to determine if infection has occurred. This requirement reflects current CDC recommendations (Ex. 4B).

Paragraph (g)(3)(i)(D) requires that when an employee has a TB skin test conversion, the employee receive a medical history, a physical examination, medical management and follow-up, and other tests and procedures determined to be necessary. This provision assures that employees with skin test conversions receive appropriate evaluation for preventive therapy and for infectious tuberculosis. OSHA included the provision for early identification of disease since, as the CDC has stated in their guidelines, infectious tuberculosis disease can be prevented by the early treatment of tuberculosis infection.

In paragraph (g)(3)(i)(E), the proposed standard requires employers to provide TB skin testing within 30 days prior to termination of employment. The rationale for this requirement is two-fold. First, this requirement permits employees whose employment is terminated after an unrecognized exposure incident, but before their next regularly scheduled TB skin test, to determine their current (exit) TB skin test status. OSHA recognizes that in some instances employees may be in the process of converting from negative to positive TB skin test results at the time of the exit testing and that some of these cases will be missed. Also missed will be employees who decline testing or who vacate their position immediately or without notice. While such situations are possible, the Agency believes that these occurrences would be rare. Secondly, by detecting recent conversions, appropriate steps can be taken by the employer to investigate the cause of the exposure. This helps prevent future exposures in those areas or situations where the exiting employee's infection may have occurred.

Paragraph (g)(3)(i)(F) requires that a medical history, physical examination, TB skin testing, determinations of the employee's ability to wear a respirator, medical management and follow-up or other related tests and procedures be conducted at any other time determined necessary by the physician or other licensed health care professional, as appropriate. This allows the physician or other licensed health care professional, as appropriate, to recognize the individual differences in employees' medical status and response to TB infection and increase the frequency or content of examination as needed. Some workers who have certain health conditions may need more frequent evaluation (Ex. 4B). For example, individuals who have a condition that may interfere with an accurate interpretation of TB skin test results (e.g., the development of test anergy in an employee who is on chemotherapy for cancer treatment), may warrant more frequent evaluations because of the high risk for rapid progression to TB disease if he or she becomes infected. (Ex. 4B)

Paragraph (g)(3)(ii) sets forth provisions regarding employees who wear respirators. Paragraph (g)(3)(ii)(A) requires that a face-to-face determination of the employee's ability to wear the respirator be accomplished before initial assignment to a job with occupational exposure (or within 60 days of the effective date of the standard) and at least annually thereafter. As discussed above under explanation of terms, this is a verbal exchange to assess health factors that could affect the employee's ability to wear a respirator. An initial determination is made before assignment to a job requiring respirator use to assure that the employee's health factors have been properly evaluated prior to incurring exposure to M. tuberculosis. This determination must also be made annually to assure that no health conditions have arisen that might limit an employee's ability to wear a respirator.

Such conditions may arise and be noted prior to the annual determination. For example, the employee may experience unusual difficulty while being fitted or while using the respirator. In these situations, it is not appropriate to wait until the annual determination. Therefore, paragraph (g)(3)(ii)(B) requires that a face-to-face determination of the employee's ability to wear a respirator, including relevant components of a medical history and, if indicated, a physical examination and other related tests and procedures, be provided whenever the employee experiences unusual difficulty while being fitted or while using a respirator.

Paragraph (g)(3)(iii) requires employers to provide TB skin tests every 6 months for each employee who enters AFB isolation rooms or areas, performs or is present during the performance of high-hazard procedures, transports or is present during the transport of an individual with suspected or confirmed infectious TB in enclosed vehicles, or works in intake areas where early identification is performed in facilities where 6 or more individuals with confirmed infectious TB have been encountered within the past 12 months. OSHA believes that employees who perform these activities are exposed more intensely and frequently to individuals with suspected or confirmed infectious tuberculosis and should, therefore, be tested more frequently.

(4) Additional Requirements

Paragraph (g)(4) (i) through (iv) contain the additional requirements an employer must meet. Paragraph (g)(4)(i) requires that the physician or other licensed health care professional, as appropriate, verbally notifies the employer and the employee as soon as feasible if an employee is determined to have suspected or confirmed infectious tuberculosis. In this way an infectious employee can be removed from the workplace, thereby minimizing occupational exposure for other workers. Paragraph (g)(7)(i), Written Opinion, allows 15 days before the employer must provide the employee with the written opinion of medical evaluations from the physician or other licensed health care professional, as appropriate. In situations where an employee is determined to be potentially infectious, this time period leads to unnecessary delays in removal from the workplace and disease treatment. Therefore, OSHA requires the verbal notification to expedite treatment and prevent spread of disease to other employees.

The proposed standard, in paragraph (g)(4)(ii), requires the employer to notify each employee who has had an exposure incident when the employer identifies an individual with confirmed infectious TB who was previously unidentified. For example, if a newly admitted patient undergoes diagnostic and therapeutic evaluation for suspected pulmonary malignancy, and the diagnosis of infectious tuberculosis is not made until several days after hospitalization, all hospital staff who have had exposure must be identified and provided TB skin test and follow-up. OSHA intends to assure that employees are provided with opportunities for early detection of tuberculosis infection. These provisions are consistent with the general purpose of tuberculosis medical surveillance as recommended by the CDC, and they are included to assist all employees in receiving the full benefits provided by the standard.

Determination of the drug susceptibility of the M. tuberculosis isolate from the source of an exposure incident resulting in a TB skin test conversion is required by paragraph (g)(4)(iii) unless the employer can establish that such a determination is infeasible. Information regarding drug susceptibility assists the examiner in deciding the most effective treatment therapy for the exposed employee, particularly if the source is a drug resistant strain of M. tuberculosis. Drug susceptibility testing of the source isolate is recommended by CDC (Ex. 4B). OSHA includes the provision regarding infeasibility because certain TB skin test conversions may involve unknown exposure sources. This can make identification of the isolate and therefore drug susceptibility testing infeasible or even impossible. It is the responsibility of the employer to establish that this is infeasible, if such is the case. Employers must make a good faith effort to identify M. tuberculosis isolates and obtain the drug susceptibility testing.

Paragraph (g)(4)(iv) requires the employer to investigate and document the circumstances surrounding an exposure incident or TB skin test conversion and to determine if changes can be instituted that will prevent similar occurrences in the future.

The provision assures that employers obtain feedback regarding the circumstances of employee exposures and use the information to eliminate or decrease specific circumstances leading to exposure. For example, exposure incident investigation shows that an employee was exposed to tuberculosis as a result of recirculation of air containing infectious droplet nuclei. Further investigation shows inadequate local or general ventilation in the workplace. The employer can now repair the ventilation system and prevent future exposure incidents. Another example of corrective measures may be including a stronger training emphasis on certain procedures where proper work practices might have decreased the likelihood of transmission of tuberculosis. Employers can obtain further guidance regarding investigations for TB skin test conversions and exposure incidents in health care workers by reading the 1994 CDC guidelines.

(5) Medical Removal Protection

Paragraph (g)(5)(i) requires that employees with suspected or confirmed infectious tuberculosis be removed from the workplace until determined to be non-infectious according to current CDC recommendations. Infectious TB is contagious and removal is essential for the protection of other workers. An employee's "infectiousness" is determined by the physician or other licensed health care professional, as appropriate, who informs the employer as required in paragraphs (g)(4)(i) and (g)(7) of this section.

Paragraph (g)(5)(ii) states that for employees removed from the workplace under paragraph (g)(5)(i), the employer shall maintain the total normal earnings, seniority, and all other employee rights and benefits, including the right to former job status, as if the employee had not been removed from the job or otherwise been medically limited until the employee is determined to be noninfectious or for a maximum of 18 months, whichever comes first. Paragraph (g)(5)(iii) provides medical removal protection for employees removed from the workplace under paragraph (f)(4)(viii) of Respiratory Protection. The provision requires the employer to transfer the employee to comparable work for which the employee is qualified or can be trained in a short period (up to 6 months), where the use of respiratory protection is not required. OSHA requires that if no such work is available, the employer shall maintain the employee's total normal earnings, seniority, and all other employee rights and benefits until such work becomes available or for 18 months, whichever comes first.

The requirement referring to the employee's right to return to his or her former job is not intended to expand upon or restrict any rights an employee has or would have had, to a specific job classification or position under the terms of a collective bargaining agreement. Where the employer removes an employee from exposure to tuberculosis, the employee is entitled to full medical removal protection benefits as provided for under the standard.

The medical removal requirement is an indispensable part of this standard. The medical removal protection helps assure that affected employees participate in medical surveillance and seek appropriate care. If employees fear losing their jobs as a result of their medical condition they may attempt to hide the illness, thereby infecting many more workers and other people and jeopardizing their own health. The requirement for medical removal assures that an infectious employee will not be terminated, laid off, or transferred to another job (possibly at a lower pay grade) upon returning to work. Consequently, this protection should reduce reluctance on the part of the employee to participate in medical surveillance. The employee's health will be protected and the health of co-workers and others who come into contact with that employee will be protected, also.

OSHA believes that the cost of protecting worker health to the extent feasible is an appropriate cost of doing business since employers are obligated by the OSH Act to provide safe and healthful places of employment. Consequently, the costs of medical removal, like the costs of respirators and engineering controls, are borne by employers rather than individual workers.

If a removed employee files a claim for workers' compensation payments for a tuberculosis-related disability, then the employer must continue to provide medical removal protection benefits pending disposition of the claim. To the extent that an award is made to the employee for earnings lost during the period of removal, the employer's medical removal protection obligation may be reduced by such amount. The employer's obligation to provide medical removal protection benefits to a removed employee may be reduced to the extent that the employee receives compensation for earnings lost during the period of removal either from a publicly or employer-funded compensation program, or receives income from employment with another employer which was made possible by virtue of the employee's removal.

Medical removal should not be viewed as an alternative to primary control (prevention) of workers' exposure to tuberculosis; rather, it should be used as a secondary means of protection, where other methods of control have failed to protect. The stipulation of an 18 month time period of protection is consistent with other OSHA standards (e.g., Cadmium, 29 CFR 1910.1027; Lead in Construction, 29 CFR 1926.62). The provision of medical removal and the costs associated with the program may indirectly provide employers with economic incentives to comply with other provisions of the standard. It can be expected that the costs of medical removal will decrease as employer compliance with other provisions of the standard increases.

(6) Information Provided to Physician or Other Licensed Health Care Professionals

Paragraph (g)(6)(i) requires the employer to assure that the health care professionals responsible for the medical surveillance receive a copy of this regulation. OSHA believes it is the employer's responsibility to inform the health care professionals responsible for medical surveillance of the requirements of this standard. This will help assure that these individuals are aware of and implement the requirements. This provision is included in other OSHA standards (e.g., Benzene, 29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030).

Paragraph (g)(6)(ii) requires the employer to assure that the physician or other licensed health care professional, as appropriate, evaluating an employee after an exposure incident receives: (A) A description of the exposed employee's duties as they related to the exposure incident; (B) a description of the circumstances under which the exposure incident occurred; (C) the employee's diagnostic test results, including drug susceptibility pattern, or other information relating to the source of exposure that could assist in the medical management of the employee; and (D) all of the employee's medical records relevant to the medical evaluation of the employee, including TB skin test results. Since the individual responsible for medical surveillance may not necessarily be the person evaluating an employee after an exposure incident, it is necessary to also provide a copy of this standard to the evaluating physician or other appropriate licensed health care professional, as required by paragraph (g)(6)(i). In this way, the evaluator will also be informed of and implement the standard's requirements. All of the above information is essential to follow-up evaluation, and helps assure that an accurate determination can be made regarding appropriate medical treatment of the exposed employee. This provision is consistent with other OSHA standards (e.g., Bloodborne Pathogens, 29 CFR 1910.1030, Benzene, 29 CFR 1910.1028).

(7) Written Opinion

Paragraph (g)(7)(i) states that the employer shall obtain and provide the employee with a copy of the written opinion of the physician or other licensed health care professional, as appropriate, within 15 days of the completion of all medical evaluations required by this section. The purpose of requiring the employer to obtain a written opinion is to assure that the employer is provided with documentation that the medical evaluation of the employee (1) has taken place and that the employee has been informed of the results; (2) has included an evaluation of the employee's need for medical removal or work restriction; (3) describes the employee's TB skin test status so that the employer can assess action needed to prevent further exposure; and (4) informs the employer of the employee's infectivity status so that the employer can take action to prevent the employee from becoming a source of infection for other employees.

The employer has a right to know the information contained in the written opinion and may retain the original written opinion, but must provide a copy to the employee. The 15 day provision assures that the employee is informed in a timely manner regarding information received by the employer and is consistent with other OSHA standards (e.g., Formaldehyde, 29 CFR 1910.1048; Benzene, 29 CFR 1910.1028; Bloodborne Pathogens, 29 CFR 1910.1030).

In addition, the written opinion is required to assure the employer that the employee has been provided with information about any medical conditions resulting from exposure to tuberculosis which require further evaluation or treatment.

OSHA believes it is important that employers know if their employees have had evaluations for tuberculosis infection or exposure incidents, and that physicians or other appropriate licensed health care professionals, acting as agents for the employer, have provided the employer with written documentation that these evaluations occurred. However, paragraph (g)(7)(ii) limits the information the employer is provided in order to protect the privacy of the employee. The requirement for a written opinion after a medical evaluation has been included in other OSHA standards (e.g., Occupational Exposures to Hazardous Chemicals in Laboratories, 29 CFR 1910.1450; Formaldehyde, 29 CFR 1910.1048; Bloodborne Pathogens, 29 CFR 1910.1030).

Paragraph (g)(7)(ii)(E) requires the written opinion to state any recommendations for medical removal or work restrictions and the employee's ability to wear a respirator. This recommendation must be in accordance with paragraphs (g)(5)(i) and (f)(5)(viii) of this section. Including this information in the written opinion assures that the employer is provided with written documentation of the need for removal of an employee with infectious tuberculosis from the workplace. The provision also assures that the employer is aware of any work restrictions on the employee and the employee's ability or inability to wear a respirator. This information enables the employer to take appropriate steps in managing the employee's duties upon return to the workplace. OSHA recognizes the need for this provision and has included it in other standards (e.g., Lead in Construction, 29 CFR 1926.62).

Paragraph (g)(7)(iii) states that all other findings or diagnoses shall remain confidential and shall not be included in the written report. OSHA believes that all health care professionals have an obligation to view medical information gathered or learned during tuberculosis medical surveillance or post-exposure evaluation as confidential medical information. As stated previously, the maintenance of confidentiality encourages participation in medical surveillance by allaying employee concern that medical conditions unrelated to tuberculosis exposure will be communicated to the employer. OSHA also recognizes that successful medical surveillance and medical management and follow-up programs must guarantee this confidentiality, the specific requirements on confidentiality can be found in applicable state and federal laws and regulations that cover medical privacy and confidentiality. Finally, OSHA recognizes the need for this provision and has included it in other standards (e.g., Bloodborne Pathogens, 29 CFR 1910.1030).

Paragraph (h) Communication of Hazards and Training

Paragraph (h), Communication of Hazards and Training, addresses the issues of transmitting information to employees about the hazards of tuberculosis through the use of labels, signs, and information and training. These provisions apply to all operations that come under the coverage of paragraph (a), Scope, of this section. Although OSHA has an existing standard, Hazard Communication (29 CFR 1910.1200), which requires an employer to inform employees about the hazards of chemical substances they are exposed to occupationally, that standard does not apply to biological hazards such as TB. Consequently, it is OSHA's intent in this paragraph to assure that employees will receive adequate warning through labels, signs, and training so that the employee understands the hazard and can take steps to eliminate or minimize his or her exposure to tuberculosis.

Paragraphs (h)(1) and (h)(2) of the proposed standard for tuberculosis provide the specific labeling and sign requirements that are to be used to warn employees of hazards to which they are exposed. The requirements for labels and signs are consistent with section 6(b)(7) of the OSH Act, which prescribes the use of labels or other appropriate forms of warning to apprise employees of occupational hazards. As noted in paragraphs (c)(2)(v), (d)(3), and (d)(5) above, settings where home health care and home-based hospice care are provided are not required to have engineering controls and, therefore, the signs and labeling would not be required in these cases.

Labels

Paragraph (h)(1)(i) requires that air systems that may reasonably be anticipated to contain aerosolized M. tuberculosis must be labeled at all points where ducts are accessed prior to a HEPA filter and at duct access points, fans, and discharge outlets of non-HEPA filtered direct discharge systems. The label must state "Contaminated Air -- Respiratory Protection Required." The provision for labeling of air ducts that may reasonably be anticipated to contain aerosolized M. tuberculosis, with the proposed hazard warning, is supported by the CDC in its discussion of HEPA filter systems. This discussion states:

Appropriate respiratory protection should be worn while performing maintenance and testing procedures. In addition, filter housing and ducts leading to the housing should be labeled clearly with the words "Contaminated Air" (or a similar warning). (Ex. 4B)

The intent of this provision is to assure that employees who may be accessing these systems for the purposes of activities such as maintenance, replacement of filters, and connection of additional ductwork are warned of the presence of air that may contain aerosolized M. tuberculosis so that appropriate precautions can be taken. Consequently, labels are to be placed at all points where these systems are accessed.

In situations where air that may reasonably be anticipated to contain aerosolized M. tuberculosis is discharged directly to the outside, the exhaust outlets are also to be labeled. This is especially important since these outlets will most likely be at a remote location from the contaminated air source. Employees working in these locations would have no warning of the hazard if these ducts were not labeled. In addition, a number of exhaust outlets from a variety of sources may be present in an area (e.g., a hospital roof). In such situations, labeling also serves to distinguish contaminated air exhaust outlets from others in the vicinity.

The proposed provision does not require that a symbol (e.g., "STOP" sign) be included on the duct labels. OSHA believes that, in many situations, the label will be stenciled onto the duct, similar to the labeling used on other piping and duct labels currently being employed in some of these facilities. In addition, the group of workers accessing ducts will likely be a well-defined, skilled group that can be trained to recognize the text's warning. However, OSHA seeks comment on whether a symbol on duct labels is necessary and any information regarding the current use of such symbols.

Paragraph (h)(1)(ii) requires that clinical and research laboratory wastes that are contaminated with M. tuberculosis and are to be decontaminated outside of the immediate laboratory must be labeled with the biohazard symbol or placed in a red container(s). This provision is intended to assure that employees are adequately warned that these containers require special handling. In addition, the label or color-coding serves as notice that certain precautions may be necessary should materials in the container be released (e.g., a spill). This provision closely follows the recommendations outlined in the CDC-NIH publication "Biosafety in Microbiological and Biomedical Laboratories" (Ex. 7-72) and is in accordance with the labeling requirements of paragraph (e)(2)(i)(D), Clinical and Research Laboratories, of this section.

Signs

Paragraph (h)(2) contains the provisions relative to the posting of warning signs in areas where employees may be exposed to droplet nuclei or other aerosols of M. tuberculosis. More specifically, paragraph (h)(2)(i)(A) requires that signs be posted at the entrances to rooms or areas used to isolate an individual with suspected or confirmed infectious TB. The term "rooms or areas" is used in order to expand the requirement beyond the AFB isolation room or area. Throughout the course of a day various employees may enter such rooms or areas in order to carry out their duties. These employees can include physicians, nurses, respiratory therapists, housekeepers, and dietary workers. Posting a sign at the entrance of those rooms or areas where an individual with suspected or confirmed infectious TB is isolated serves to warn employees that entry into the room or area requires that certain precautions be taken. In addition, the employer may have implemented a program to minimize the number of employees who enter such rooms or areas. In this case, the sign serves as notice that entry may not be permitted for a particular employee or group of employees. As an additional public health benefit, such signs will also provide warning to visitors or family members who may be entering the area and are unaware of the hazard.

Paragraph (h)(2)(i)(B) requires that signs be posted at the entrances to areas where procedures or services are being performed on an individual with suspected or confirmed infectious TB. Although it is critically important to provide appropriate warning to employees who may inadvertently enter an isolation room, other areas of the facility are of concern as well. Special treatment areas, such as bronchoscopy suites, respiratory therapy areas where cough-inducing procedures are performed, or radiology examination rooms may, at one time or another, be occupied by an individual with suspected or confirmed infectious TB. When individuals with suspected or confirmed tuberculosis are occupying these areas, the area must have signs placed at the entrances in order to warn employees of the hazard.

The risk of exposure to aerosolized M. tuberculosis also exists in clinical and research laboratories where specimens, cultures, and stocks containing the bacilli are present. Therefore, paragraph (h)(2)(i)(C) requires that a sign be posted at the entrance to laboratories where M. tuberculosis is present. Posting of such a sign is consistent with the recommendations of the CDC/NIH publication "Biosafety in Microbiological and Biomedical Laboratories" (Ex. 7-72) and is in accordance with the sign posting requirement of paragraph (e)(2)(ii)(E), Clinical and Research Laboratories, of this section.

Even though a suspected or confirmed infectious individual is no longer present in a room or area, the droplet nuclei generated by that individual may continue to drift in the air. Consequently, the air in the room or area presents a risk of TB infection until the droplet nuclei are removed. With this in mind, paragraph (h)(2)(ii) requires that when an AFB isolation room or area is vacated by an individual with suspected or confirmed infectious TB, unless the individual has been medically determined to be noninfectious, the sign shall remain posted at the entrance until the room or area has been ventilated according to CDC recommendations for a removal efficiency of 99.9 %, to prevent entry without the use of respiratory protection [The rationale for specifying this removal efficiency has been discussed previously under paragraph (d), Work Practices and Engineering Controls]. This provision is supported by the CDC's current recommendations for tuberculosis control (Ex. 4B).

The CDC has published guidelines regarding the length of time for such sanitation of the room air based upon the air exchanges per hour (see Appendix C of this section). Requiring that the sign remain posted until the room or area is adequately ventilated will assure that unprotected employees do not inadvertently enter while an infection risk is still present.

Until such time as the room or area has been adequately ventilated, employees entering the area must wear respiratory protection. This paragraph is designed to address the situations where employees will be entering or using a room or area previously occupied by an individual with suspected or confirmed infectious TB before the room or area has been satisfactorily ventilated. For example, when an infectious tuberculosis patient is discharged from a facility and the room is needed for an incoming new patient, certain housekeeping and maintenance functions need to be done between patient occupancies. Employees who must perform the tasks required to prepare the room for the next patient must wear respiratory protection until such time as the room has been adequately ventilated, based upon the CDC criteria. Obviously, if the room was previously occupied by an individual with suspected infectious TB and that individual is medically determined to be noninfectious, it would not be necessary to ventilate the room to remove M. tuberculosis nor to continue to post a sign at the entrance to the room since there would be no tuberculosis bacilli present.

OSHA has given much consideration to what sign should be required for posting outside of isolation rooms or areas and for areas where procedures or services are performed on individuals with suspected or confirmed infectious TB. The purpose of the sign is to convey a uniform warning along with the necessary precautions to be used for the particular situation.

The sign recommended by the CDC in 1983 in their "CDC Guidelines for Isolation Precautions in Hospitals" (Ex. 7-112) read "AFB Isolation" and then listed the requirements for entry. However, the instructions on the CDC sign are different from OSHA's requirements. For example, the sign instructed workers that "Masks are indicated only when patient is coughing and does not reliably cover mouth", a recommendation that is currently outdated and no longer recommended by CDC. The document contained another sign for "Respiratory Isolation" but this sign was designed for use with a number of respiratory hazards (rubella, meningococcal meningitis, chickenpox) that are not addressed in OSHA's proposed standard. Neither the 1990 CDC tuberculosis guidelines (Ex. 3-32) nor the 1994 CDC tuberculosis guidelines (Ex. 4B) provided help with this issue. OSHA also considered using a sign having the words "AFB Isolation" however, there is some concern that "AFB Isolation" could compromise patient confidentiality. For example, that sign outside of a treatment area or isolation room would allow members of the public or employees with no "need to know" to discern the potential diagnosis of the individual being isolated.

In addition, OSHA was unable to find uniform recommendations about signs in sources outside of the CDC. A number of facilities use signs to warn employees of the hazard of TB, but these signs vary widely and often had been developed for a particular facility. Thus, facilities that were using TB warning signs did not appear to be universally applying a specific sign.

The Agency does not believe, however, that development of a sign should be left to individual employers since this could lead to a variety of signs that may not provide adequate warning of the hazard. In the work settings covered by the proposal, there are many employees who move from facility to facility or even from industry to industry. In fact, a substantial number, like contract nurses, will work in several facilities at one time. A universal sign will enable these employees to recognize the hazard wherever it occurs and then take proper precautions. The issue of whether OSHA should specify colors that must be included on the sign was raised at TB stakeholder meetings. OSHA realizes there is a part of the population, perhaps as high as 10 % of all men, that is color blind and that at some work sites some colors have been employed that are different from the red that OSHA proposes be used. However, stakeholders, particularly those whose jobs took them to several different work sites, urged OSHA to require a standardized sign and, of those who considered the issue, there was general agreement that the red on the familiar "stop" sign was appropriate. OSHA has preliminarily concluded that the colors required provide needed warning even though not all employees (e.g., those who are color blind) may benefit from them, and that the colors chosen are consistent with conventions on health signage. The Agency has developed a sign that it believes will provide appropriate warning and be easily recognizable. Failing to find either a guideline recommendation or a generally accepted community standard regarding what sign should be placed at the entrances to these areas, OSHA looked to generic, broad-based sources for symbols which would be easily identifiable, understandable to workers who were not able to read well or are non-English speaking, and simple to construct.

In paragraph (h)(2)(iii), therefore, OSHA is proposing that a "STOP" sign with the accompanying legend, "No Admittance Without Wearing A Type N95 Or More Protective Respirator", meets these criteria. The sign is easily recognizable, requires a simple color scheme, and should be understandable to employees with minimal training.

OSHA is seeking information on the effectiveness of the proposed sign to warn workers of the presence of a hazard, as well as information on other signs that may be more effective. Please be specific when providing information, keeping in mind the wide variety of work sites where signs will be needed. Where an alternative is being proposed, please enclose a model or drawing as well as the rationale for believing that it will be more effective than OSHA's proposed sign.

Paragraph (h)(2)(iv) requires that signs at the entrances of clinical or research laboratories and autopsy suites where procedures are being performed that may generate aerosolized M. tuberculosis include the biohazard symbol, name and telephone number of the laboratory director or other designated responsible person, the infectious agent designation "Mycobacterium tuberculosis", and special requirements for entering the laboratory or autopsy suite. This provision has been taken directly from the CDC/NIH publication "Biosafety in Microbiological and Biomedical Laboratories" (Ex. 7-72). As previously discussed, the purpose for this sign is to warn employees of the potential TB hazard and inform them of precautions that must be taken to prevent exposure.

Information and Training

It is OSHA's position that employees must understand the nature of the hazards in their workplace and the procedures to follow in order to eliminate or minimize their risks of exposure to these hazards. (Exs. 4-B, 7-169, 7-170, 7-61, 7-64) In the case of M. tuberculosis, employee exposures may result in a TB infection, which may ultimately result in disease and even death. The provisions in paragraph (h)(3) of this proposed standard set forth the training that each employer must provide to his or her employees. OSHA believes that effective training is a critical element in any occupational safety and health program. In this proposed standard, the employer would be required to provide training for each employee covered by the scope of the standard.

Paragraph (h)(3)(i) requires that employers assure that each employee with occupational exposure participates in training, which must be provided at no cost to the employee and be made available at a reasonable time and place. Since appropriate training is considered to be critical in assuring employee protection, the employer is responsible for making sure that each employee with occupational exposure participates in the training program. Having the employee pay in some manner for all or part of the training or requiring the employee to attend training at an unreasonable time and place would be a disincentive to participation. If training cannot feasibly be provided during work hours, employees are to be paid for training scheduled outside of normal working hours.

In view of the importance of training, OSHA is proposing that it be provided at several particular points in time. (Exs. 7-169; 4-B) More specifically, paragraph (h)(3)(ii) requires that training be provided: (A) before initial assignment to tasks where occupational exposure may occur, for those employees without previous occupational exposure; (B) within 60 days after the effective date of the final standard, for those employees who have occupational exposure at the time of the standard's promulgation; and (C) at least annually thereafter, unless the employer can demonstrate that the employee has the specific knowledge and skills required under paragraph (h)(3)(vii). The employer must provide re-training to an employee in any of the topic(s) in paragraph (h)(3)(vii) in which that employee cannot demonstrate the necessary knowledge and/or skill. This approach to training frequency assures that employees entering jobs with occupational exposure will be fully trained before exposure occurs. In addition, employees who are already working in jobs with occupational exposure at the time of the standard's promulgation will receive training and must become knowledgeable in all of the required aspects of the standard (e.g., employer's exposure control plan, medical surveillance program, warning signs and labels) within a short period of time.

Annual re-training reinforces the initial training and provides an opportunity to present new information that was not available at the time of initial training. The Agency recognizes that, as a result of training previously provided by the employer, employees may possess some of the knowledge and skills listed in the training topics in paragraph (h)(3)(vii). Consequently, OSHA is proposing that re-training be provided annually unless the employer can demonstrate that the employee has the specific knowledge and skills required by this paragraph. The employer must provide re-training to an employee in any topic(s) in paragraph (h)(3)(vii) in which the employee cannot demonstrate specific knowledge and skills.

An employee with occupational exposure to TB who moves to a job with another employer that also involves occupational exposure to TB would not need to meet all of the initial training requirements. In such instances, the Agency has determined that the employee's prior training in the general topics required by the standard (e.g., the general epidemiology of tuberculosis, the difference between tuberculosis infection and tuberculosis disease) would remain relevant in the new work setting and that the new employer need not re-train in these topics. However, the employee would not possess knowledge of the topics required by the standard that are specific to the new employer's particular work setting (e.g., the new employer's exposure control plan and respiratory protection program and the means by which the employee could access the written plans for review). OSHA is proposing to permit limited "portability" of training, as noted in the standard. This note states that training in the general topics listed in paragraph (h)(3)(vii) that has been provided in the past 12 months by a previous employer may be transferred to an employee's new employer. However, the new employer must provide training in the site-specific topics listed in paragraph (h)(3)(vii) in accordance with the requirements of paragraph (h) (e.g., at no cost to the employee and at a reasonable time and place).

OSHA is aware that some employers have already established training for their occupationally exposed employees. (Ex. 7-169) In light of this, paragraph (h)(3)(iii) of the proposed standard requires only that limited training be conducted for those employees who already have received training on tuberculosis in the year preceding the effective date of the standard. The additional training would only have to address those provisions of the standard not previously covered in the earlier training.

The requirement for annual training within one year of the employee's previous training, in paragraph (h)(3)(iv), assures that each employee receives training within 12 calendar months of his or her last training. Annual training is not based on a calendar year; that is, training will not be permitted to be provided to an employee in January of one year and in December of the following year, essentially a 23-month span between training sessions. Employers may establish schedules for training around this requirement.

Also, paragraph (h)(3)(v) stipulates that the employer must provide additional training whenever changes in the occupational environment, such as modification of tasks or procedures or institution of new tasks or procedures, affect the employee's occupational exposure to M. tuberculosis. This provision will assure that employees remain apprised of any new exposure hazards and the precautions necessary to protect themselves from exposure. This additional training does not need to entail a complete reiteration of the annual training, but may be limited to addressing the new sources of potential exposure.

The proposed standard requires that training material be used that is appropriate in content and vocabulary to the educational level, literacy and language of employees. Employees must be able to comprehend the information being conveyed in order for it to be useful. Therefore, the employer has the responsibility for assuring that the training is provided in an understandable manner to the audience being addressed. This provision would assure that employees, regardless of their educational or cultural background, will receive adequate training.

Paragraph (h)(3)(vii) of the proposed standard contains the specific elements that would comprise a minimum training program. (Exs. 4-B; 7-169; 7-64) The provisions for employee training are performance oriented, stating the categories of information to be transmitted to employees and not the specific ways that this is to be accomplished. This assures that important information is communicated to employees about the nature of this occupational hazard while allowing employers the most flexible approach to providing training. OSHA has set forth the objectives to be met and the intent of training. The specifics of how the employer assures that employees are made aware of the hazards in their workplace and how they can help to protect themselves are left up to the employer who is best qualified to tailor the training to the TB hazards in his or her workplace.

The proposed standard would require the employer to explain a number of particular topics in the training session(s). Paragraph (h)(3)(vii)(A) requires the employer to provide an explanation of the contents of this standard and the location of an accessible copy of the regulatory text and appendices to this standard. This enables the employee to have access to the standard and to become familiar with its provisions. It is not necessary for the employer to provide each employee with a copy of the standard; it is sufficient for the employer simply to make a copy accessible. For example, a copy of the standard could be posted in a location where it could be readily and easily viewed by employees.

An important element in the training involves an overview of the epidemiology of tuberculosis, the pathogenesis of the disease and an explanation of various aspects of risk to employees. (Ex. 4B) More specifically, paragraph (h)(3)(vii)(B) requires that the training include an explanation of: the general epidemiology of tuberculosis, including multidrug-resistant TB and the potential for exposure in the facility; the signs and symptoms of TB, including the difference between TB infection and TB disease; the modes of transmission of tuberculosis, including the possibility of reinfection in persons with a positive tuberculin skin test; and the personal health conditions that increase an employee's risk of developing TB disease if infected.

Since the employer can tailor the training to the needs of his or her employees, the training program will likely be more technical for some audiences and less technical for others. The general goal of this paragraph is to assure that each employee being trained understands what tuberculosis is, how it is spread, and possible risks that may affect the employee.

Employees need to be able to recognize symptoms associated with TB disease. (Ex. 4B) The employee must understand that certain symptoms (e.g., a persistent cough lasting 3 or more weeks, bloody sputum, night sweats, anorexia, weight loss, fever) may be related to TB. In addition, information on non-occupational risk factors that place employees at increased risk of developing tuberculosis disease following an infection permits those individuals at increased risk to make informed decisions about their employment situations.

Paragraph (h)(3)(vii)(C) requires an explanation of the employer's exposure control plan and respiratory protection program. Employees must also be informed about what steps they need to take to review the written plans, if they so desire.

Paragraph (h)(3)(vii)(D) requires the employer to train employees regarding the tasks and other activities that may involve occupational exposure to tuberculosis. Employees must be made aware of those job duties which may expose them to tuberculosis. For example, although certain health care professionals may easily recognize the hazard involved in transporting a person with infectious TB, the staff of a correctional facility may not. On the other hand, some health care professionals may not immediately recognize that their mere presence in a room where an individual with suspected or confirmed infectious TB is being X-rayed presents an exposure risk and necessitates wearing a respirator. All occupationally exposed employees need training that will enable them to recognize those activities that put them at risk of exposure.

Paragraph (h)(3)(vii)(E) of this section requires employers to train employees regarding both the uses and limitations of various control measures, specifically those used at the employees' worksite. Exposed employees must be familiar with the employer's tuberculosis policies and procedures in order for them to be properly implemented. Control of exposure frequently involves using a variety or combination of engineering controls, administrative controls, work practice procedures and personal protective equipment. To assure that employees will be able to identify and implement methods of reducing occupational exposure to tuberculosis, they must understand how these controls are applied in their work sites and the limitations thereof. With this understanding, employees will be more likely to use the appropriate control for the situation at hand and to use it correctly. For example, employees must be able to recognize the labels and signs used to identify rooms or areas where suspected or confirmed infectious individuals are present so that they can take appropriate precautions before entering. Understanding of the limitations of control measures will also enable employees to recognize when inappropriate or inadequate control measures have been taken and increases the likelihood that they will report such situations.

Training must be relevant to the specific site where the employee will be working. Each employee must know, for example, the procedures used in his or her particular facility to identify suspected infectious TB cases, where respiratory protection is kept, and what engineering controls are in place within the facility. This training is particularly important for workers who move between several facilities in the course of their work, for example, "leased" personnel, part-time employees, "moonlighters", or contractors.

The provision covering the selection, types, proper use, location, removal and handling of respiratory protection, paragraph (h)(3)(vii)(F), is particularly important because many of the employees and employers proposed to be covered by the tuberculosis standard may not be accustomed to the use, selection, and upkeep of respiratory protection. Consequently, training on aspects such as the necessity for respiratory protection, the appropriate type of respiratory protection, where to obtain it, and its proper use, fit, and the general upkeep is necessary to assure the effectiveness of respirator use. (Ex. 7-64)

OSHA believes that employees who have a clear understanding of the medical surveillance program (its purpose, methodology, and the significance of the results of examinations and tests), will be much more likely to participate in that program. Therefore, paragraph (h)(3)(vii)(G) requires that the training include an explanation of the employer's medical surveillance program, including the purpose of tuberculin skin testing, the importance of a positive or negative skin test result, anergy testing, and the importance of participation in the program. This increased participation by trained employees helps the employee to identify changes in his or her personal health status and also aids the employer in assessing the effectiveness of his or her TB control program.

Each employee must understand the actions to be taken if an occupational exposure occurs as well as what is available to them regarding appropriate medical treatment, prophylaxis, and post exposure follow-up in order for the employee to lessen the chance of developing active disease. Therefore, paragraph (h)(3)(vii)(H) would require an explanation of the procedures to follow if an exposure incident occurs, including the method of reporting the incident, an explanation of the medical management and follow-up that the employer is required to provide, and the benefits and risks of drug prophylaxis. In addition, the employee must be provided with an explanation of the procedures to follow if the employee develops signs or symptoms of tuberculosis disease [paragraph (h)(3)(vii)(I)]. In this way, an employee who notes the signs or symptoms of personal disease development will be aware of the appropriate steps to take, thereby speeding initiation of medical evaluation. Quick evaluation protects the employee, co-workers, and the public.

In paragraph (h)(3)(viii), the proposed standard mandates that the person conducting the training must be knowledgeable in the subject matter as it relates to the specific workplace being addressed. OSHA believes that a variety of persons are capable of providing effective training to employees. OSHA has approached this section of the proposed standard in much the same way as the trainer requirements were addressed in the standard for Occupational Exposure to Bloodborne Pathogens. That is, a knowledgeable trainer is one who is able to demonstrate expertise in the area of the occupational hazard of tuberculosis and is familiar with the manner in which the elements of the training program relate to the particular workplace.

A number of resources are available through the Centers for Disease Control and Prevention and professional organizations such as the American Lung Association and the American Thoracic Society that can be used to educate trainers and prepare them for this task. In addition, specialized training courses in the area of tuberculosis control can also assist in educating trainers (Ex. 7-189).

In addition to general knowledge of the subject matter, it is important that the trainer be able to instruct the participants in site-specific features of the Exposure Control Plan that will reduce their risk in the particular facility. This benefits not only employees within the facility but also provides temporary employees with the information needed to protect themselves against exposure while working in the facility. For example, workers who have received general training by their employer (e.g., a personnel staffing agency) will also receive training about the facility where they will actually perform their duties (e.g., a specific hospital).

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