Chlorine gas is considered a TIH under certain conditions.

• A. False—chlorine is TIH only at high pressure
• B. True
• C. False—chlorine never TIH
• D. Not enough data

Answer: (B)

Chlorine gas is a TIH (toxic inhalation hazard) under conditions where inhalation exposure could occur. The key idea is that TIH refers to hazards that affect people through breathing in the substance, not just by contact or ignition. Chlorine is a highly toxic respiratory irritant; when released as a gas, it can irritate, damage the lungs and airways, and can be life-threatening at sufficient concentrations or exposure times. This hazard exists even at normal pressures—the danger comes from inhalation of enough chlorine gas, not from high pressure alone. Therefore, chlorine is considered TIH in transport and emergency response contexts because its inhalation toxicity poses a serious risk to anyone who could breathe contaminated air.