SUFFOCATING AGENTS

If inhaled, these types of chemicals cause fluid to build up in the lungs (pulmonary edema), making it difficult to breathe and can cause death.

Phosgene

Phosgene is a chemical agent that has the odor of newly mowed hay. This highly toxic substance immediately irritates the eyes, nose, and skin. It also produces tissue damage within several minutes of contact. Phosgene exposure is diagnosed by recognizing the signs and symptoms (eye and airway irritation, difficulty breathing, chest tightness, and delayed pulmonary edema). There is no specific antidote for phosgene. Decontaminating all exposed areas is the most effective means of decreasing tissue damage.

Cyanide

Cyanide is a colorless liquid that prevents cells from using oxygen, which results in death. Breathing is the primary mode of exposure. Cyanide in moderate amounts may produce headache, nausea, dizziness, weakness, or anxiety. A large amount of cyanide will produce loss of consciousness within seconds, and death may occur within minutes. Treatment for acute cyanide poisoning depends upon rapidly providing oxygen and the use of antidotes (amyl nitrite, sodium thiosulfate, and sodium nitrite). For more information on cyanide, consult the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. 

Chlorine

Chlorine is a greenish-yellow gas with an irritating odor. Chlorine is a potent irritant to the eyes and skin. Exposure also causes severe lung irritation that may result in death. Chlorine exposure is difficult to diagnose. There is no specific antidote. Victims need to be removed from the source and provided with fresh air. If eyes or skin were exposed, they should be rinsed with plenty of water. Oxygen should be provided if there is shortness of breath or difficulty in breathing. For more information on chlorine, consult the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs.