Lung-damaging agents

In high concentrations, chlorine gas, phosgene, ammonia, sulphur dioxide and hydrogen chloride are lethal, because they damage the lung tissues. Chlorine and phosgene both irritate the eyes, the gullet, the respiratory tract and the lungs. After heavy exposure, the cause of death is often a combination of suffocation, due to reduced lung functions, and of excessive strain on the heart.