Solving the Safety Challenges of Solvents
Most of the hazards on the typical jobsite are pretty obvious. From sharp edges on tools to dangerous heights, they have built-in warnings that help workers stay aware and alert.
On the other hand, one workplace hazard can be very sneaky. In fact, by the time a worker notices that he or she has been dangerously exposed, it may be too late to do anything about it.
That hazard is what’s known as solvents — chemical liquids that have a wide variety of uses on worksites. Most commonly, workers encounter solvents when they’re used to clean up or dissolve difficult materials such as paints, greases, or oils. If you’ve used mineral spirits to clean a paint brush or a rag soaked in gasoline to clear residue off of a piece of equipment, you’ve encountered solvents.
Solvents are also present in a number of common products, where they’re used to suspend or deliver other chemicals. Examples include paint, inks, pesticides, and epoxy resins. Often (but not always), the unpleasant odor given off by those products is caused by the solvent becoming vapor as it evaporates.
Because workers encounter solvents so frequently, they may not give much thought to them when it comes to safety. That’s a mistake, though, because many solvents are extremely hazardous. In some cases, contact with solvents can cause serious burns or other problems to skin. With other types of solvents, the primary hazard involved breathing the solvent fumes. In this article, we’ll look at those dangers and steps workers can take to protect themselves.
SOLVENTS AND SKIN
Solvents can affect the skin in two ways. First, some solvents can be absorbed through the skin, where they can travel to organs or other systems and cause damage. In some cases, those solvents can carry hazardous chemicals with them.
The second way is by irritating the skin and causing what’s known as dermatitis. Many types of solvents will attack the natural oils that protect skin, making it dry or causing it to break out. Solvents can also cause or aggravate skin allergies, leading to painful irritation. As the skin is exposed to more solvent, it can become even more sensitive, making the irritation even worse.
Protective clothing, such as chemical-resistant gloves and aprons, is your best defense against damage to skin. Common sense applies, too. It’s not a good idea to use solvents to remove glues or paint from your hands.
Don’t assume that any type of glove will offer adequate protection. Gloves made from cloth or leather may absorb the solvent and keep them against your skin for a longer time. Latex gloves may dissolve when exposed to some types of solvents.
Chemical-resistant gloves are specially designed to withstand most kinds of solvents, but always verify that the type of glove is appropriate for the material you’re using. Inspect the gloves before wearing them, too. Any small hole or worn area can allow solvents to get through to your hands.
SOLVENTS AND EYES
Nearly everyone is aware that getting chemicals such as solvents in their eyes can cause irritation and even permanent damage such as blindness. What many workers don’t realize is that some solvents can be absorbed into the body through the eyes.
That’s why it’s so important to use the recommended eye protection to keep liquid splashes from reaching your eyes. Also be aware that some solvent vapors can be very irritating to eyes.
SOLVENTS AND BREATHING
The biggest source of solvent exposure involves inhaling vapors. Most solvents evaporate quickly into the air, so anyone breathing that air will inhale some quantity of the solvent. That can causes anything from headache and dizziness to even unconsciousness and death, depending on the toxicity of the solvent and the amount that’s inhaled.
While many solvents have strong, unpleasant odors that serve as a warning sign, others are completely odorless and colorless, so you may not even be aware of the exposure. Even in cases where there’s no immediate damage, inhaled solvents can accumulate in body tissue and cause long-term damage to organs and systems. What’s more, the solvent may affect your judgment or awareness, increasing the chance that you’ll have an accident.
Solvents that become vapors are generally assigned Permissible Exposure Limits (PELs) that define how much can be present in the air before the situation becomes hazardous. The lower the PEL, the more dangerous the particular solvent is.
Your best defense against solvent fumes is a properly ventilated workspace. Either general or exhaust ventilation (or a combination) may be used to provide protection. General ventilation is used primarily to bring fresh air into the workplace and dilute the solvent, while exhaust ventilation removes the vapors from confined workspaces.
Workers may believe that respirators are the best protection against solvent vapors, but they should really be a last resort because of several reasons. For one, a single type of respirator will not work most efficiently with every type of solvent. In addition, if the respirator doesn’t fit securely against your face, it won’t offer adequate protection — but if respirators do fit tightly, workers may find them uncomfortable. They can also interfere with workers’ ability to communicate important information. That’s why it’s better to provide sufficient ventilation than to trust a respirator.
Other steps can be taken to minimize the presence or amount of vapors in the air. For example, promptly resealing or covering solvent containers when the material is not in use will keep excess vapors from forming. It’s also a good idea to prohibit the use of solvents in workspaces that lack adequate ventilation or can be characterized as confined spaces.
FIRES AND EXPLOSIONS
One of the biggest hazards of any solvent is that vapors may be flammable. Some are even explosive. Generally speaking, the greater a solvent’s volatility (the rate at which it changes from a liquid to a vapor), the greater its flammability.
It’s important to know the flashpoint of solvents used in the work area. The flashpoint describes the temperature at which enough vapors are being released so that a spark or a flame could ignite the vapors. When a flashpoint is 100° F or lower, the solvent is referred to as “flammable.” Those with higher flashpoint temperatures are known as “combustible” solvents.
While most workers recognize that they shouldn’t smoke, use open flames, or create sparks around solvents that can burn, many aren’t aware of situations in which dangers may inadvertently arise. For example, when you pour a solvent from one contain into another, some static electricity may be present, and could create enough of a spark to ignite any vapors. That’s why it’s always a good idea to ground metal containers when solvents are being poured from or into them.
Solvents should be stored in containers that have been designed for them, and placed in well-ventilated, fire-resistant areas that have appropriate fire extinguishers available within reach.
KNOW YOUR SOLVENTS
Workers need to be aware of all the solvents being using on the jobsite, the steps they can take to protect themselves, and what actions should be taken in the event of a spill or injury. It’s in their best interest to read labels and material safety data sheets (MSDS) for each solvent, and a requirement for their employer to make that information available and provide appropriate training on the proper handling.
Of course, the best way to eliminate hazards involving solvents is to eliminate the solvents themselves. Consider using other non-volatile materials that may accomplish the task. If solvents must be used, a less-toxic solvent or one with lower volatility may be a better choice.