Which statement best identifies chlorine as a pulmonary (choking) agent?

• A. It primarily affects the skin
• B. It primarily affects the lungs via inhalation
• C. It only affects the eyes
• D. It is primarily a blood agent

Answer: (B)

Chlorine is a pulmonary choking agent because its primary danger comes from inhalation and direct damage to the respiratory system. When breathed in, chlorine gas irritates the mucous membranes of the airways, causing coughing, chest tightness, and shortness of breath. It can lead to rapid pulmonary edema as the lungs struggle to exchange gases. The gas reacts with water in the lungs to form hydrochloric and hypochlorous acids, which injure the airway lining and promote inflammation and mucus production, further impairing breathing. Exposure can irritate the eyes and skin as well, but the defining feature that makes it a pulmonary agent is the predominant, exposure-driven injury to the lungs and airways from inhalation. It is not a blood agent, which would imply a primary effect on cellular respiration in the blood rather than the lungs.