MC 331 containers carry products that have high vapor pressures. These products belong to which hazard class?

MC 331 containers carry products that have high vapor pressures. These products belong to which hazard class?

• A. Hazard class 2
• B. Hazard class 3
• C. Hazard class 4
• D. Hazard class 6

Answer: (B)

High vapor pressure means a liquid readily forms vapors at room temperature. When those vapors are flammable, the material is classified as a flammable liquid, which falls under hazard class 3. MC-331 containers are designed for high‑vapor‑pressure liquids, so they carry materials in this class. The other classes cover gases (hazard class 2), flammable solids (hazard class 4), and toxic substances (hazard class 6), which don’t match the scenario of a high‑vapor‑pressure liquid being carried in an MC‑331 tank.

High vapor pressure means a liquid readily forms vapors at room temperature. When those vapors are flammable, the material is classified as a flammable liquid, which falls under hazard class 3. MC-331 containers are designed for high‑vapor‑pressure liquids, so they carry materials in this class. The other classes cover gases (hazard class 2), flammable solids (hazard class 4), and toxic substances (hazard class 6), which don’t match the scenario of a high‑vapor‑pressure liquid being carried in an MC‑331 tank.