Laboratories contain many common sources of flammable gas and vapor which can pose a fire or explosion hazard in the presence of a competent ignition source. While all facilities handling hazardous materials should follow the hierarchy of process safety controls, the nature of research laboratories is often such that flammable vapors or gases are unavoidable. Accordingly, the use of hazardous area electrical classification is a key component of an overall ignition source control strategy. This article outlines major concepts associated with area classification for vapors and gases in the context of the hierarchy of controls, and offers practical suggestions for how to limit risk in research laboratories.