A simple asphyxiant. Phosgene - COCl2 is used in organic synthesis, in manufacture of dyes, pharmaceuticals, herbicides, insecticides, synthetic foams, resins, and polymers. Phosgene is a lund irritant and extremely toxic. It is also produced in the presence of refrigerants that are drawn through a heat source, refrigeation technicians should take extreme caution and prevent the exposure by making sure that smokeing is avoided in the presence of refrigerants and preventing inhalation of the gas when soldering or brazing. It first came into prominence during World War I, when it was used, either alone or mixed with chlorine, against troops.
Inhalation causes severe lung injury, the full effects appearing several hours after exposure.
First prepared in 1811, phosgene is manufactured by the reaction of carbon monoxide and chlorine in the presence of a catalyst. With water, phosgene reacts to form carbon dioxide and hydrochloric acid.