Exposure to _________ would MOST likely result in immediate respiratory distress.

Exposure to _________ would MOST likely result in immediate respiratory distress.

• A. Ammonia gas
• B. Chlorine
• C. Ozone
• D. Carbon monoxide

Answer: (B)

Focus on how the gas affects the airways right after inhalation. Chlorine gas is an extremely potent respiratory irritant that reacts with moisture in the airway to form hydrochloric and hypochlorous acids. These acids injure the lining of the respiratory tract, causing rapid inflammation, coughing, bronchospasm, and swelling that can lead to immediate dyspnea and respiratory distress. Ammonia is also a strong irritant, but its effects, while abrupt, depend more on concentration and exposure duration and often involve burning of the eyes and mucous membranes in addition to airway irritation. Ozone irritates the lungs as well, but its onset of distress can be less predictable and sometimes develops with time after exposure. Carbon monoxide causes hypoxia by binding to hemoglobin rather than directly irritating the airways, so it typically produces systemic symptoms like headache or dizziness rather than immediate airway distress. So, chlorine stands out as the gas most likely to produce immediate respiratory distress due to its direct and rapid chemical injury to the airway.

Focus on how the gas affects the airways right after inhalation. Chlorine gas is an extremely potent respiratory irritant that reacts with moisture in the airway to form hydrochloric and hypochlorous acids. These acids injure the lining of the respiratory tract, causing rapid inflammation, coughing, bronchospasm, and swelling that can lead to immediate dyspnea and respiratory distress.

Ammonia is also a strong irritant, but its effects, while abrupt, depend more on concentration and exposure duration and often involve burning of the eyes and mucous membranes in addition to airway irritation. Ozone irritates the lungs as well, but its onset of distress can be less predictable and sometimes develops with time after exposure. Carbon monoxide causes hypoxia by binding to hemoglobin rather than directly irritating the airways, so it typically produces systemic symptoms like headache or dizziness rather than immediate airway distress.

So, chlorine stands out as the gas most likely to produce immediate respiratory distress due to its direct and rapid chemical injury to the airway.