The book Bob (petersonra) is referring to is Electrical Installations in Hazardous Locations, by Peter J. Schram and Mark W. Earley.
The biggest problem we usually have in answering electrical area classification (rather than electrical installations in classified locations) questions in this forum is there is often not enough detail about the processes involved. In other words, are you manufacturing, storing large quantities, simply "using" relatively small amounts of ??acetone, toluene, xylene plus others,? etc. They could each result in different electrical area classifications from none to Division 1, depending on the conditions
Electrical area classification is simply not a trivial exercise.
The most likely applicable Standard is NFPA 30, Flammable and Combustible Liquids Code, especially chapters 1, 7, and 8. If you are dealing with a manufacturing process then NFPA 497 is probably the better document.