Zyklon B is a systemic chemical asphyxiant that halts the cellular uptake of oxygen by binding to iron in the bloodstream, causing cytotoxic hypoxia. Initial symptoms include weak pulse, rapid breathing, vomiting and convulsions. Heart rate slows, body temperature drops, and the victim suffers a coma and death.
As Zyklon B concentration increases, death occurs more rapidly. Symptoms of poisoning occur from inhalation at 20 parts per million; whereas, death occurs in less than one minute of exposure at 2,000 parts per million, explains the International Cyanide Management Code.
Zyklon B directly affects organ systems, which are sensitive to low oxygen, such as the central nervous system, cardiovascular system and pulmonary system, notes the Centers for Disease Control and Prevention. Inhalation rapidly dissolves hydrochloric cyanide upon contact with moist mucus membranes of the eyes, nose and mouth. Exposure by skin contact is accelerated if skin is cut, moist or abraded.
Human toxicity is dependent on the method of exposure and varies based on the dose-response effect of different individuals; however, the biochemical process is consistent in entering the bloodstream as described by the International Cyanide Management Code. Preventing the absorption of oxygen in the blood causes the body to switch to anaerobic metabolism. Lactic acid builds in the bloodstream causing lactate acidosis. The combined effect of cytotoxic hypoxia and lactate acidosis results in depression of the central nervous system, respiratory arrest and ultimately death, notes the International Cyanide Management Code.