Hazardous Materials Awareness Army 74D Practice Test

Gases are categorized under Class 2, with divisions that separate flammable, non-flammable, and toxic gases. Propane is a flammable hydrocarbon that forms ignitable mixtures with air at typical ambient conditions, so it belongs in Division 2.1. The 68-degree reference just confirms we’re at ambient conditions where propane remains a gas and retains its flammable hazard. Other divisions describe different hazards: Division 2.2 is non-flammable gases, Division 2.3 is toxic gases, and the explosive divisions (Division 1.x and Division 1.4) cover explosive hazards not applicable to a typical propane gas. Therefore, the appropriate division for a flammable gas at room temperature is Division 2.1.