Irritant gas inhalation injury

[Jason Yan]

Irritant gases are those which, when inhaled, dissolve in the water of the respiratory tract mucosa and cause an inflammatory response, usually due to the release of acidic or alkaline radicals. Irritant gas exposures predominantly affect the airways, causing tracheitis, bronchitis, and bronchiolitis. Other inhaled agents may be directly toxic (eg, cyanide, carbon monoxide) or cause harm simply by displacing oxygen and causing asphyxia (eg, methane, carbon dioxide).
The effect of inhaling irritant gases depends on the extent and duration of exposure and on the specific agent.
Chlorine, phosgene, sulfur dioxide, hydrogen chloride, hydrogen sulfide, nitrogen dioxide, ozone, and ammonia are among the most important irritant gases. Hydrogen sulfide is also a potent cellular toxin, blocking the cytochrome system and inhibiting cellular respiration. A common exposure involves mixing household ammonia with cleansers containing bleach; the irritant gas chloramine is released.
(See also Pulmonary Chemical Warfare Agents and Overview of Environmental Pulmonary Disease.)