Which DOT Class number corresponds to Gas hazards?

• A. DOT Class 7
• B. DOT Class 6
• C. DOT Class 2
• D. DOT Class 5

Answer: (C)

Gas hazards are classified as Class 2 in the DOT system. This category covers any material that is a gas at normal temperature and pressure, including compressed, liquefied, and dissolved gases stored under pressure. The key idea is the gaseous form itself, which brings specific behaviors—rapid expansion, movement with air currents, and distinct risks such as asphyxiation for non‑toxic gases or ignition hazards for flammable gases. Knowing a substance is a gas guides how it is labeled, packaged, and handled during transport, and informs the emergency response approach to leaks or releases. The other classifications cover different hazard types (for example, toxic/infectious substances, radioactive materials, oxidizers/organic peroxides), which are not gas hazards.