Almost every workplace—and home—contains solvents. They’re among the most useful of substances. But, if not used carefully, some solvents also are very hazardous.
Solvents, which are usually liquids, are used to dissolve other materials. Among their most common applications are vapor degreasing, corrosion removal and heavy cleaning. They’re a mainstay of many operations.
You have undoubtedly used solvents without being aware that’s what they were. Some of the many solvents you might have worked with include alcohol, turpentine, acetone, formaldehyde, toluene, methylene chloride and trichloroethylene. Each has different uses and hazards.
Health problems are a particular concern when you work with solvents. Eye contact can cause irritation, burning, or conjunctivitis (pink eye). It could also damage the eye or even lead to blindness. Skin contact also poses problems, including potential rashes, skin burns or dry scaly skin. Inhalation and swallowing are usually the biggest concerns with solvents. Many solvents evaporate quickly and have no color or noticeable smell. You could inhale solvent vapors without even realizing it and if inhaled, they can move quickly into the bloodstream. Once inhaled, they can cause headaches and dizziness, nausea and vomiting, fatigue and drowsiness, a sore throat and respiratory irritation, tremors and even blurred vision. Inhaling some solvents, such as trichloroethylene, also can make you feel as if you’re drunk, with the same loss of mental focus and physical coordination.
Prolonged or heavy exposure to some solvents can even be life threatening. Among the serious effects are permanent damage to the liver, kidneys and central nervous system. Some solvents may cause cancer. Serious overexposure may, in the worst cases, cause unconsciousness or even death.
With all these potential health problems, plus the risks of fire, explosion and pollution from careless waste disposal, it’s obviously essential to take no chances when working with solvents.
Solvents are regulated by the Occupational Safety and Health Administration’s (OSHA) Hazard Communication Standard (29 CFR 1910.1200), because they are dangerous chemicals. As you know, that regulation requires companies to inform employees about the hazards of the substances they encounter on the job, including solvents. You also have to receive training on how to protect yourself from these hazards by following material safety data sheet (MSDS) precautions and using company-provided equipment and protective clothing.
You determine a solvent’s hazards the same way you learn about the hazards of any substance, by checking its label and MSDS. You have to pay particular attention to health hazards and to protective equipment and procedures. The MSDS also will alert you to whether, and in what conditions, the solvent may burn or explode. Never work with a hazardous substance until you study its label and MSDS. While you may want to zero in on areas of particular concern, such as solvent inhalation hazards, it’s important to check out everything on the label and MSDS before starting any task.
Of course, if there is no label or if the label is incomplete, stop right there. Even if you’re sure you know what’s in the container, using an unlabeled substance is an unacceptable risk. Report the problem immediately. If the solvent has a complete label and MSDS, then you can prepare yourself to work safely before you start the job.
The Clean Air Act requires the Environmental Protection Agency (EPA) to regulate emissions of toxic air pollutants from a published list of industrial sources referred to as “source categories.” As required under the Act, the EPA has developed a list of source categories that must meet control technology requirements for these toxic air pollutants. The EPA is required to develop regulations (also known as rules or standards) for all industries that emit one or more of the pollutants in significant quantities. The EPA has developed implementation tools (i.e., checklists, brochures) to help comply with the standards. The Web site, http://www.epa.gov/ttn/atw/degrea/halopg.html, proposes the rules that govern halogenated cleaning solvents (degreasing organic cleaners).
Solvents used in equipment cleaning make up a big part of the hazardous wastes from repair shops. You can help protect the environment, your workers and save money (see sidebar, “Paint solvent recycling is worth the investment,” for more money-saving tips) by reducing the amount of solvent you use, by reusing or recycling your solvent and by using the least hazardous solvent that will do the job.
Many solvents contain volatile organic compounds (VOCs). These are chemicals that get into the air and can harm people and the environment. The MSDS will have information on the amount of VOCs in the products you buy. Always try to use material with the lowest percentage of VOCs possible.
Many waste solvents are hazardous wastes. Some used solvents and still bottoms are on a list of hazardous wastes called the F list. Some unused solvents are on the U list. Common listed hazardous waste solvents include trichloroethylene, tetrachloroethylene (perc), methylene chloride, xylene, acetone, methyl ethyl ketone, toluene and others.
The rules that apply to your shop depend on the solvent types and quantities you use, as well as the size of your operation. Your solvent supplier should be able to tell you if your solvent is regulated as a hazardous waste, or you can check with the manufacturer. If you cannot find out from these sources, contact the EPA or CCAR-GreenLink for help. You will need the MSDS listing the chemicals in your solvent and the flash point. The flash point is the temperature at which the solvent vapor will catch on fire.
Some used solvents are hazardous because they are ignitable, toxic, reactive or corrosive. If the waste solvent has a flash point of less than 140ºF it is an ignitable hazardous waste. Waste solvent should be reused, recycled on-site, recycled off-site or, as a last resort, disposed of as a hazardous waste.
Solvents can be expensive to purchase and to dispose of. It makes good sense to reduce the amount of solvent you use. Often the solvent you use can be reused or recycled, which means you can purchase less new solvent. When you reduce the amount of solvent you use, you save money and protect the environment.
Protection against hazards
Now that you’re aware of solvent hazards, let’s look at the ways to protect yourself from them. The first option is to reduce the use of hazardous solvents. You always should be looking for less hazardous substitutes. You also should try to replace hazardous solvents with water-based cleaning methods, waterless cleaners or mineral spirits.
One way to reduce the amount of solvents you use is to use any solvent completely, until it has lost its ability to clean (also known as reuse). You should also minimize loss to evaporation by keeping containers closed when not in use and by keeping solvents in containers whose exposed surface area is as small as possible. But because you can’t eliminate all use of hazardous solvents, you have to take other protective steps.
To prevent a fire when you’re working with flammable solvents, adhere to the following:
- Use the solvent only in well-ventilated areas.
- Be sure containers are grounded before transferring solvents.
- Remove all heat and ignition sources from the area—flames, sparking tools, even static electricity from clothing, etc.
- Don’t smoke.
- Don’t use open or unapproved lamps.
- Keep containers tightly covered when not in use.
Another potential solvent hazard is ground or water contamination. Steps to effective spill control include:
- Keeping containers closed when not in use.
- Inspecting containers regularly for leaks, corrosion, dents, etc., and reporting any problems immediately.
- Cleaning up solvent leaks promptly and properly.
- Place solvent wastes carefully in proper containers for recycling or disposal. Never put even a drop into drains, sewage or regular trash.
Preventing dangerous exposure
As you know, engineering controls are the first line of protection from chemical hazards. The No. 1 engineering control for solvents is ventilation systems. They play a key role in preventing solvent vapors from building up to dangerous concentrations. When you work with solvents be certain ventilation equipment is working and report any problems immediately. Because solvents are often invisible and odorless, you won’t know they’re present until it’s too late.
Another way to control exposure to solvents is to use them in enclosed processes that prevent vapors from escaping. For example, vapor degreasing is often done in tanks with local exhaust ventilation. Some vapor degreasing operations also use refrigeration to condense the vapor so it drips back into the solvent tank. You can avoid direct contact by using equipment like tongs, tweezers, hemostats and wire dunk buckets to handle the solvent.
When engineering controls aren’t enough to keep solvent exposure at a safe level, the next line of defense is personal protective equipment (PPE) and clothing. PPE can keep you from having skin or eye contact with solvents and prevent dangerous inhalation.
The MSDS will tell you what kind of protective clothing you need to protect yourself from an individual solvent’s hazards. Don’t even consider casually substituting PPE made of a different material. You have to be sure you’re really protected. Check the MSDS to get the particulars on the gear you’ll need, which will probably include splash-proof goggles and face shields; gloves (see sidebar, “Recommended glove material for solvents”); and impervious clothes or aprons.
As Teresa Kostick, owner and manager of All Line CARSTAR in Bolingbrook, Ill., stated: “As human beings it is our responsibility to take care of each other, so just purchasing gloves for the handling of different solvents isn’t enough. Making certain that they are used on a daily basis is what really matters.”
Because it’s particularly dangerous to inhale some solvents, you may have to wear a respirator. As you know, careful selection and fit-testing are essential if you want a respirator to give you the protection you need.
So far, you’ve learned about equipment and procedures designed to reduce your potential exposure to solvents. Don’t limit these precautions to big jobs or jobs that use a large quantity of solvents. Because solvents are so common, we often forget to pay the same close attention to safety and the environment on a small job or one that uses just a small amount of solvent.
It’s also important to prevent indirect exposure to solvents by following these rules:
- Don’t eat, drink, smoke, or apply cosmetics in an area that contains solvents.
- Don’t leave food or beverages, mugs or utensils in solvent work or storage areas.
- Don’t wash with solvents. They may do an effective cleaning job, but they can also harm your skin.
- Wash thoroughly after handling solvents.
- Don’t wear contact lenses when you work with solvents; they can trap fumes.
- Remove contaminated PPE carefully to avoid spreading the solvent to your skin, street clothes or clean parts of the facility.
Another part of solvent safety is knowing what to do in an emergency. The MSDS will give you valuable advice, including what to use to put out a fire or clean up a spill. These emergencies demand prompt responses. Clean up the smallest spills yourself, if you are properly outfitted and have the right equipment. Otherwise, don’t linger if there’s a fire or spill. There may be invisible vapors that could cause or intensify a fire or put your health at risk. Immediately notify emergency response personnel. Alert others in the area to the danger and get out quickly so trained responders can do their job.
If you become aware of solvent vapors in an area where you don’t have adequate respiratory protection, leave the area immediately. Inform others of the danger so they can get out and, if possible, close doors and vents behind you. Then report the situation to the people assigned and trained to handle it.
These situations may also demand immediate first aid for exposure. The MSDS will tell you exactly what to do for exposure to a particular solvent. But following are some general practices to keep in mind:
- For inhalation, move to fresh air immediately. Victims with significant exposure may need artificial respiration or CPR.
- For eye contact, flush with lots of water for 20 minutes.
- For skin contact, wash thoroughly with soap and water for at least 15 minutes. Don’t scrub.
- For swallowing, call for emergency medical assistance immediately. Then follow the instructions on the label and/or MSDS. Never, however, give fluids to an unconscious person.
First aid is a beginning, but it may not be enough. Because of the serious potential effects of solvent exposure, get medical attention as quickly as possible.
Every substance we use in the workplace requires special attention. Even the most common substances may not be risk-free. Fortunately, MSDSs give you good information on hazards, along with instructions on protective equipment and safety practices that enable you to get the benefit of these substances without causing accidents or health problems.
Solvents are also good examples of the fact that hazards can exist even when we can’t see or smell them. You must take time to identify what you’re working with and what precautions it requires.
Furthermore, to assist the industry in seeking alternative, less-hazardous solvents, you should review the EPA’s Solvents Alternative Guide (SAGE) at http://es.epa.gov/ssds/sagedown.html. This online guide provides pollution prevention information on solvent and process alternatives for parts cleaning and degreasing.