Solvents and Fire Safety


Fire is undiscriminating. It can flare up at any time. And can happen to anyone. After finishing a vinyl graphics application job, a former colleague and mentor had loaded the back seat of his car with rags which had been soaked in solvent for cleaning, before heading down the road. As John drove, he attempted to light one cigarette with another, that he had just finished smoking. After getting a light, he threw the old cigarette out the window. Unbeknownst to John, the cigarette blew back into his car, landing in the pile of rags. Shortly thereafter the rags ignited. As long flames trailed out the back windows of his car, alarmed motorists frantically honked their horns to alert John of his precarious predicament.

Many of the solvents that are used in sign making and screen printing are either flammable or combustible.  Flammable solvents are those that can have a “flash point” at temperatures lower than 100°F.  The flash point is the lowest temperature at which a solvent can catch fire – the lower the flash point, the more dangerous the solvent.  Combustible solvents can catch fire at temperatures at higher than 100°F but lower than 200°F.  The following is a list of some common solvents that might be in your shop:


Acetone Flammable
Adhesive Remover Highly Flammable
Brush Cleaner Flammable
Denatured Alcohol Highly Flammable
Enamel Reducer Extremely Flammable
Lacquer Thinner Extremely Flammable
Mineral Spirits Combustible
Paint Conditioner/
Flow Enhancer
Turpentine Flammable
Wax & Grease Remover Highly Flammable
Xylene Flammable


Keep solvents and other hazardous materials in clearly labeled containers with the name of the chemical or brand name. To minimize the risk of fire, all flammable liquids, regardless of the amount, must be stored in a fireproof cabinet. This is an OSHA regulation.  Solvent-soaked rags should also be stored in covered metal containers. Never store any type of combustible material in a furnace room.

When using solvents, make sure that your workplace has   good ventilation. Solvent vapors can become concentrated near open containers of liquid solvent. These invisible vapors are very dangerous. Remember, the vapors burn, not the liquid. It only takes a spark or high temperatures to start a fire.

Lead By Example

If you want your employees to follow your shop’s safety rules, lead by setting a good example. As fire marshal in my home town, my father often pontificated about fire safety.  He didn’t always abide by the rules.

One rule that regularly broke was never to work with a solvent near an open flame. An gallon of solvent, such as lacquer thinner has the explosive power of several sticks of dynamite. Its fumes are extremely flammable and easily ignite with a spark.

My father learned his lesson, when he was cleaning brushes and tried to light a cigarette. His hands went up in flames, resulting in second-degree burns. From then on, he practiced what he preached.  

For more ideas on how you can prevent fires at work or in your home, read  ‘The Comprehensive Resource of Fire Safety Tips’: