There are hundreds of species of mold, which is a variety of fungus. Molds occur naturally and are always present in small quantities indoors as well as outdoors. They usually pose no hazard to people. However, problems may arise when quantities of mold grow beyond usual limits or when particular types of mold are introduced into the indoor environment.

• Irritation
  Exposure to mold can irritate the eyes, nose, and upper breathing passages. Symptoms of irritation include burning eyes, nasal congestion, coughing, and post-nasal drip.
  
• Allergy
  Many people become allergic to mold and develop hay fever or asthma symptoms such as itchy, watery eyes, nasal congestion, sneezing, chest tightness, cough and wheezing.
  
• Toxins
  Some molds create chemicals, called toxins, that can cause illness. While much remains unknown about mold toxins, it appears that some molds produce toxins that can have effects on the skin, the respiratory system, the immune system, and the nervous system.
  
• Infection
  Some molds can also cause infection, such as chronic sinus infections. Other types of mold-induced infection are much less common, and occur mainly among people with weakened immune systems. Examples of individuals with weakened immune systems include those with HIV infection, those receiving chemotherapy, and the elderly. Children and pregnant women may also be at increased risk.

Symptoms caused by workplace exposure to mold usually occur or get worse at work, then get better away from work. Try to identify an exposure source. Mold can often be seen (black, green, or brown discoloration) and/or smelled. Sometimes, however, it is hidden behind walls, floor or ceiling, or the source is elsewhere in the building.

Excessive moisture in materials such as sheetrock, wood, paper, particle board, fiberglass insulation, carpeting, paint, plaster, soil in plant pots, and cooked and raw food provides a place for mold to grow. Mold will grow almost anywhere -- behind walls, under floors, above ceiling tile, inside air conditioning and heating systems.

Moisture can originate from a number of sources, including leaking roofs, improperly sealed window frames, leaking pipes, damp ground, condensation on cold surfaces, or insufficiently dried building materials (after a flood, spill or leak). Keeping humidity and moisture problems under control is the main way to prevent unhealthy mold buildup.

Besides excessive moisture and consequent growth of mold, there must also be some way for the mold spores or toxins to become airborne so that we can breathe them in. Normal activity indoors can do this. Building renovation activities or changing carpets can disperse even greater amounts of mold spores, one reason these activities often result in upper respiratory problems. Sometimes a building's heating, ventilation, and air conditioning (HVAC) system is the mechanism, sending mold to parts of a building or throughout the whole building.

You can check visually for the presence of mold growth, which can cause discoloration of almost any color –

• on walls, ceiling, and floor in the basement
  
• in crawl spaces and lower rooms
  
• anywhere there has been a spill or water damage
  
• on window frames and outside walls
  
• on carpets (check backing in water-stained areas)
  
• on ceiling tiles
  
• on paper or wood products
  
• behind bubbling paint or stained/peeling wallpaper or sheetrock.
  

The following can indicate the presence of mold or potential for mold growth –

• earthy or musty odor
  
• signs of chronic roof or plumbing leaks
  
• wet or dirty insulation on ducts or pipes
  
• damp or dirty carpet
  
• recent spills or flooding
  
• standing water near outside air intakes
  
• slimy or foamy water in drip pans of air- handling or air-conditioning units
  
• extensive exposed soil indoors
  
• over-watered indoor plants

An employer's responsibility
If there is visible mold, contact your employer to have it removed. It is unacceptable to have ongoing mold growth in occupied indoor spaces. Expensive testing and sampling are generally not necessary where mold is visible. It can be unwise to delay taking action or cleaning up the mold while waiting weeks or months for lab reports.

Complete removal is critical
A clean-up that kills the mold but leaves it in place is not sufficient. Adverse health effects can result from exposure to dead mold spores as well as live mold spores. Besides cleanup, it is essential to eliminate or correct the leaks or excess moisture that can promote the growth of mold. In short, mold-related illness is best ‘treated' by eliminating the mold and its source.

Training is required
Clean-up of small, isolated areas (10 square feet or less) such as ceiling tiles or small areas on walls can be performed by regular building maintenance staff who have been trained on proper clean-up methods, potential health hazards, and safe work practices and equipment. Workers should wear respirators with a National Institute of Occupational Safety and Health rating of N95. A respirator's rating is listed on the box it comes in. A common dust mask does not meet this requirement. (Compliance with OSHA's Respiratory Protection Standard - 29 CFR 1910.134 - is mandatory when respirators are used.) Gloves and eye protection should be worn.

For small areas, a simple clean-up may be enough
Surface mold growth in small, isolated areas can be cleaned with a solution of one part bleach to ten parts water. The work space to be cleaned should be unoccupied. Apply the solution, allow it to sit for 15 minutes, then thoroughly dry. (Note: Be careful never to mix ammonia solutions with bleach.) Although this may kill the surface mold, it may not affect mold within the substrate (the material on which the mold is living), and the mold may then survive and grow. Light mold growth on small areas of wood surfaces may be sanded off. Misting of surfaces with water to suppress dust is recommended. Contaminated materials that cannot be adequately cleaned should be removed in sealed plastic bags. The work area and adjacent areas should be cleaned with a damp mop or cloth and a detergent solution and then dried. HEPA vacuuming may be appropriate.

Guidelines for larger clean-ups
Larger clean-ups should follow the procedures recommended by the New York City Department of Health's "Guidelines on Assessment and Remediation of Fungi in Indoor Environments" at http://www.ci.nyc.ny.us/html/doh/html/epi/moldrpt1.html  Copies can also be obtained from the NYC Department of Health, 125 Worth St., Room 618, Box 34C, New York, N.Y., 10013; tel: 212-788-4290.

Investigating and cleaning up any mold problem at work is your employer's responsibility. Don't assume, however, that your complaint will receive an adequate response, or that your employer even knows how to address the problem. Sometimes responsibility for dealing with the problem is delegated to an inadequately trained custodian or maintenance person. Sometimes a consultant is hired to conduct an investigation, but the consultant does not have the experience needed to assess the problem.

Because you should not assume that your employer will make an adequate response to a mold problem, it is important to work with your union, your health and safety committee, or your co-workers whenever mold is a source of concern.

Try to identify areas of mold growth and water intrusion. Review the building's history and talk to senior workers to identify past water leaks or floods. If you identify mold growth requiring remediation, document it with photographs and in writing, and provide it to the union or to management along with documentation of employee health problems.

If your employer wants to hire a consultant, make sure that the consultant has appropriate industrial hygiene qualifications and can assist with cleanup if needed. Be wary of recommendations to conduct expensive air quality testing or sampling for mold. In general such sampling should only be performed to assist with cleanup (by identifying the specific mold involved) or to help doctors treating workers for possible mold-related illnesses.

If a consultant is hired or maintenance staff are responsible for the building inspection, try to accompany them and take notes and ask questions during the investigation.

Make sure you are provided with copies of any reports that are written. Under OSHA's Access to Employee Exposure and Medical Records regulation, (29 CFR 1910.1020), employees have the right to receive copies of any records or reports concerning toxic substances or harmful physical agents in the workplace.  Click here for more information about your legal right to exposure records.

If you have a union, a grievance can be filed if necessary. OSHA might also be helpful in some cases, though without specific regulations related to indoor air quality, OSHA's hands are partially tied. If you need help, contact NYCOSH or your nearest Committee for Occupational Safety and Health (for a list, click here) or your nearest occupational health clinic (for a list of clinics in New York State, click here). The list of clinics is also available directly from the New York State Department of Health, Bureau of Occupational Health and Environmental Epidemiology, 547 River Street, Troy NY 12180; tel: 518-402-7900.

Click here for links to news articles about mold and other indoor-air-quality issues available on the internet.

See Guidelines on Assessment and Remediation of Fungi in Indoor Environments by the New York City Department of Health, Bureau of Environmental & Occupational Disease Epidemiology. Copies can also be obtained from the NYC Department of Health, 125 Worth St., Room 618, Box 34C, New York, N.Y. 10013; tel: 212-788-4290

For additional information or to learn about free training about mold, indoor air quality, or any occupational safety and health topic, visit How NYCOSH Can Help or contact NYCOSH at 116 John Street, Suite 604, New York, N.Y. 10038; tel: 212-627-3900; email: nycosh@nycosh.org

This factsheet made possible, in part, under a grant from the New York State Hazard Abatement Board's Training and Education Fund