Class 1: Flammable Gases or Vapors
Division 1: Concentrations of Gases or Vapors exist under normal operating conditions.
Division 2: Concentrations of Gases or Vapors are normally prevented. Group C Atmospheres such as Cyclopropane, Ethyl Ether, Ethylene, or gases or vapors equivalent in hazard. Note: Equipment must be special ordered with Group C motor. Group D Atmospheres such as Acetone, Alcohol, Ammonia, Benzene, Benzol, Butane, Gasoline, Hexane, Lacquer solvents, Naphtha, Natural Gas, Propane, or gases or vapors equivalent in hazard.
Class 2: Explosive Dusts
Division 1: Explosive dusts exist under normal operating conditions.
Division 2: Explosive dusts are normally prevented. Group E Atmospheres containing metal dust and other combustible dusts including aluminum, magnesium, and their commercial alloys, and other metals of similarly hazardous characteristics. Note: Not appropriate for atmospheres containing Uranium, Thorium or Zirconium dust Group F Carbon black, charcoal, coal, or coke and similar materials.