In this post, our focus is on the flammability aspect of solvents. Most commonly used solvents are known for their flammability. However, there are often other concerns that the user does not consider such as development of chemical sensitivity, development of dermal de-fatting, carcinogenic, organ, systemic and other short-term or long-term health effects. Commonly used flammable solvents include: acetone, MEK, lacquer thinner, ethyl acetate, ethanol, methanol, toluene, and others.
Before using any chemical, read the product label for the material(s) and the SDS (Safety Data Sheet). Follow product use directions. Properly protect yourself from exposure; wear appropriate PPE. Control sources of ignition. Dispose of contaminated materials and waste liquids properly.
Here are some other user tips:
Always keep containers closed when not in use.
Use solvents in a well-ventilated area.
Use bonding or grounding equipment to prevent static sparks.
Maintain a spill clean-up kit in the area.
In some industries, solvents are used to clean equipment. For example, in the laboratory setting sometimes acetone or other volatile solvent is used to clean vacuum pumps. While the likelihood of fire or health risk is low if proper procedure is followed, sometimes the operator may unwittingly put themselves at risk. In one case, laboratory personnel routinely cleaned their fume hood vacuum pumps by circulating acetone through them and capturing the pup discharge into an open container. Doing so would result in the liberation of volatile fumes that generally were present at below the LEL (lower explosion limit). However, in a specific case, the operator was cleaning a vacuum pump with acetone unaware that the pump electric motor had not been upgraded to an intrinsically safe, explosion proof model. As a result of having a pump in inventory that was not explosion proof, the pump did spark and ignite the acetone vapors. Fortunately for the operator, he was wearing safety eyewear and a face shield and only suffered minor first degree burns to his hands.
It is obviously important to identify all possible ignition sources when working with volatile chemicals. Sources may include electric motors that are not intrinsically safe – especially ones that the operator does not actively control such as pumps and motors that are on auto start circuitry. To learn more about requirements for the use of electrical equipment in hazardous locations, refer OSHA 29 CFR 1910.307: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9884&p_table=standards; UL (Underwriter Laboratories) UL Standard 1203: http://ulstandards.ul.com/standard/?id=1203; and also NFPA 499, Recommended Practices For The Classification Of Combustible Dusts and of Hazardous (Classified) Locations For Electrical Installations In Chemical Process Areas published by the NFPA (National Fire Protection Association) here:
We’ll talk more about static electricity as a possible ignition source in an upcoming post.