Editing Smoke screen (section)

===Zinc chloride===
Zinc chloride smoke is grey-white and consists of tiny particles of [[zinc chloride]]. The most common mixture for generating these is a [[smoke composition|zinc chloride smoke mixture]] (HC), consisting of [[hexachloroethane]], grained [[aluminium]] and [[zinc oxide]]. The smoke consists of zinc chloride, zinc oxychlorides, and [[hydrochloric acid]], which absorb the [[humidity|moisture]] in the air. The smoke also contains traces of organic chlorinated compounds, [[phosgene]], [[carbon monoxide]], and [[chlorine]].

Its toxicity is caused mainly by the content of strongly acidic hydrochloric acid, but also due to thermal effects of reaction of zinc chloride with water. These effects cause [[lesion]]s of the [[mucous membrane]]s of the upper airways. Damage of the lower airways can manifest itself later as well, due to fine particles of zinc chloride and traces of phosgene. In high concentrations the smoke can be very dangerous when inhaled. Symptoms include [[dyspnea]], retrosternal pain, [[hoarseness]], [[stridor]], [[lachrymation]], [[cough]], [[expectoration]], and in some cases [[haemoptysis]]. Delayed [[pulmonary edema]], [[cyanosis]] or [[bronchopneumonia]] may develop. The smoke and the spent canisters contain suspected [[carcinogen]]s.

The prognosis for the casualties depends on the degree of the pulmonary damage. All exposed individuals should be kept under observation for 8 hours. Most affected individuals recover within several days, with some symptoms persisting for up to 1–2 weeks. Severe cases can suffer of reduced pulmonary function for some months, the worst cases developing marked dyspnoea and cyanosis leading to death.

Respirators are required for people coming into contact with the zinc chloride smoke.