Chlorine and phosgene are known as choking/pulmonary agents.

• A. True
• B. False
• C. Not sure
• D. Not applicable

Answer: (A)

The key idea is how certain chemical gases affect the lungs. Choking, or pulmonary, agents are gases that disrupt the ability of the lungs to exchange oxygen, often causing pulmonary edema and suffocation. Chlorine gas, when inhaled, irritates and damages the airways and lung tissue; at sufficient concentrations this damage can progress to fluid buildup in the lungs, making it hard to breathe. Phosgene is a highly toxic choking agent with a notable delayed onset—people may feel fine for hours after exposure, only to develop severe pulmonary edema later. Because both gases impair the respiratory system in a way that can lead to asphyxia, they are categorized as choking/pulmonary agents.