Machinists are usually well aware of the safety hazards they face working on moving equipment. Less well known are the health hazards associated with the use of machining fluids. For example, in 1981 almost 40% of the workers at a large machining plant developed a severe flu-like illness caused by microbes that grew in the coolants or parts washers of one department and were spread throughout the plant by airborne oil mist. The microbes were related to those that cause Legionnaire's Disease. Since 1992, there have been at least eight recorded outbreaks of Hypersensitivity Pneumonitis.

1. What is hypersensitivity pneumonitis?

2. What are the symptoms of HP?

3. What should I do if I develop these symptoms?

4. How does someone get HP?

5. How do I know I don't just have a cold?

6. What are material safety data sheets?

7. Why am I getting sick now after I've been working in the same place for years?

8. What does "sensitized mean?

9. What problems are associated with biocides?

10. Is there anything that can be done to safely control bacteria in machining fluids?

11. Are skin rashes connected with the use of machining fluids?

12. How can cutting fluids cause dermatitis?

13. Is there anything else I should be doing?

14. Besides helping workers deal with these problems in the workplace, what is the labor movement doing to prevent this from happening to more workers?

15. What if I have more questions? 

What is Hypersensitivity Pneumonitis?  

Hypersensitivity pneumonitis, or HP, is an allergic-type reaction that may be caused by exposure to microbial products or other materials sometimes found in water-based machining fluids and coolants. Those chemicals affect the air sacs (alveoli) in the deepest part of the lungs. HP isn't an infection, and isn't contagious. However, it can worsen if the exposure continues.

What Are the Symptoms of HP?

If you are a machine operator who works with water-based coolants and you develop chills, run a fever, and have shortness of breath and a deep cough, you may have HP. The symptoms are like those of a cold, but they may not go away. You may feel better when you stay home, but when you return to work you may feel sick again.

What Should I Do If I Develop These Symptoms?

You should see a doctor who's board-certified in occupational or pulmonary medicine. Since you're a machine operator and your symptoms disappear when you're away from work and reappear upon returning, you likely have a work-related problem. With these symptoms, hypersensitivity pneumonitis should be suspected. We know that machining fluid exposure causes irritation and asthma. Now, several HP outbreaks have been documented among workers exposed to machining fluids. It is sometimes referred to today as "Machine Operator's Lung." If exposure continues and the HP is not treated, it may lead to permanent lung scarring and impairment. This is serious business; so don't delay in taking appropriate action.

How Does Someone Get HP?

We still don't know under what conditions coolants contain contaminants. But if contaminated mists are inhaled, they penetrate deep into the lungs and may cause HP.

How Do I Know I Don't Just Have A Cold?

HP is difficult to diagnose unless a doctor specializes in occupational or pulmonary diseases. Symptoms for HP can easily be mistaken for pneumonia, the flu, or sinus problems because the symptoms are quite similar: fever, chills, cough, shortness of breath, weakness, headache, and muscle pain. Tell your doctor about the chemicals you work with and tell him/her about "Machine Operators Lung." Take along the Material Safety Data Sheets (MSDSs) that explain the hazards related to these chemicals.

What Are Material Safety Data Sheets?

OSHA says your employer must inform you of the hazardous ingredients and the health effects of materials in writing. These are documented on the Material Safety Data Sheets (MSDS) which the law requires the product supplier to send with the first shipment of each product. The OSHA Hazard Communication standard says your employer must show you a copy of the MSDS within the workshift when you ask for it, and provide you a copy within 15 working days of your written request. Your employer is also required to hold a training session explaining the hazards and controls for materials when they are introduced for the first time, but this could have happened years ago.

Why Am I Getting Sick Now After I've Been Working in the Same Place For Years?

A: HP may have occurred in the past in machining environments, but wasn't recognized. Cases seem to be happening more often. Something may have changed in your work place. Maybe management isn't maintaining the fluid. This can cause dramatic growth of bacteria. Another possibility is an excessive application of biocides. Killing off the usual bacteria allows unusual species of micro-organisms to invade those systems. High biocide levels could cause severe irritation to your eyes, nasal passages, or throat. It is also quite possible that over the course of time you have become sensitized to biocides or other chemicals you are exposed to on the job.

What Does "Sensitized" Mean?

You may have heard about people who've been stung by bees many times in their lives, but suddenly get a sting reaction so severe they need emergency care. Suddenly their body reacted to it in a way it never had before. The same thing can happen with a chemical at work. A person could work with a chemical day-in and day-out for years with no apparent problem, and then, suddenly, that same person working the same job and dealing with the same chemical experiences a severe reaction to it. We say this person is now "sensitized." A worker sensitized to a chemical will react to very small exposures from then on. Symptoms of sensitization can include shortness of breath, wheezing, asthma, skin reactions, itching, hives, airway constriction, coma, and even death.

What Problems Are Associated With Biocides?

The most commonly used biocides are chemicals that release formaldehyde to kill bacteria. Formaldehyde is a known irritant and cancer-causing agent. Other biocides may be highly toxic when swallowed or absorbed through the skin. Biocides can also be corrosive (cause burns) to skin and eyes and can be skin sensitizers. Biocides are used to keep bacteria from eating the coolant and to prevent odors, and weren't designed to protect against respiratory problems. No one really knows how best to control bacteria in coolant systems.

Is There Anything That Can Be Done to Safely Control Bacterial in Machining Fluids?

Bacteria are not the problem. Inhaling mist is the problem. A good health and safety program for machining fluids starts with designing machinery to control mist. Hoods, splashguards, and oil mist collectors should be installed to control splashing, spraying, or mists. Health problems related to machining fluids are best solved by keeping the machine enclosed and applying exhaust ventilation.

The best control program for bacteria is common sense: Keep machines clean. Eliminate stagnant puddles of coolant on the floor and the accumulation of machine chips, sludge, dirt, and filth. These conditions create excellent breeding grounds for bacteria and other microorganisms. Management can keep a coolant from stagnating by aerating it or circulating it 24 hours a day and on weekends to aerate it. Some companies are trying to kill bacteria without chemicals. Heating the coolant to 145 degrees (called "pasteurization"), ultraviolet and gamma irradiation (similar to x-rays) may kill bacteria. Cooling the fluids can also help, by cutting bacteria growth. But we think the real solution is to control the mist.

Are Skin Rashes Connected With the Use of Machining Fluids?

Many machine operators are plagued by contact dermatitis (skin disease), the single most commonly recognized occupational disease according to national statistics. Outbreaks of dermatitis usually involve dry, cracked, scaly skin, pimples on the arms and hands, and raw sores. Workers performing the same operation and using the same types of coolants can have totally different reactions to machining fluids, and conditions may differ dramatically between different coolant systems.

How Can Cutting Fluids Cause Dermatitis?

In several ways: First, the oil and detergent in the coolant can remove the natural oil on your skin, causing it to be dry, cracked, and susceptible to infections. Second, anti-corrosion, germicidal and other additives in the machining fluids can irritate and sensitize the skin. Some coolant ingredients, such as "tall oil" (a wood-based oil) derivatives and biocides, are well-known sensitizers. Third, contaminants in the cutting fluids, like suspended particles or metal shavings, can scratch or cut the skin. Harmful bacteria can then infect the cuts.

Is There Anything Else I Should be Doing?

Find out if other workers have had the same symptoms. More than one other person with the same problem is very strong evidence of a workplace cause. If it's a union workplace, ask your health and safety representative to investigate. To play it safe, follow work restrictions recommended by your doctor. HP must be diagnosed early before irreversible damage is done. Machining fluid exposure is also a prominent cause of asthma and other respiratory conditions.

Besides helping workers deal with these problems in the workplace, what is the labor movement doing to prevent this from happening to more workers?

Unions are working for more stringent health and safety regulations. For example, in 1993, the UAW petitioned the Occupational Safety and Health Administration (OSHA) to drastically cut the Permissible Exposure Limit for workers exposed to machining fluids from 5 mg/m3 to 0.5 mg/m3. The UAW believes that an exposure limit that's 1/10 of the current legal limit is achievable and would substantially cut the risk of occupational cancer and respiratory problems.

What If I Have More Questions?

Consult your local union health and safety representative or NYCOSH.

(adapted from a UAW factsheet, 1997)