Summary points

Chemical agents should be considered in major incident planning

Consider exposure to chemical agents in any casualty with unexplained and unusual symptoms

Poisoning with many chemical agents, especially nerve agents, can be treated when diagnosed early

Protective equipment must be worn if there is suspicion that chemical agent remains in the local environment

Move casualties from contaminated environment to well ventilated area to give first aid

Decontamination of the casualty involves removal of clothing, shaving contaminated hair, and irrigation with water or dilute sodium hypochlorite to remove residual agent from skin

Use of chemical weapons in the 20th century

1914-8: Over 1 300 000 people receive gas injuries in first world war, and over 90 000 of them die

1935: Italy begins conquest of Abyssinia (Ethiopia) using mustard gas delivered by aircraft spray

1936: Japan invades China using chemical weapons (including mustard gas, phosgene, and hydrogen cyanide); German chemical laboratories produce first nerve agent — tabun

1963-7: Egypt uses phosgene and mustard aerial bombs in support of South Yemen against the Yemeni royalist forces during the Yemeni civil war

1980-8: Iraq attacks Iran and …