Background

Phosgene is a colourless, reactive, non-flammable gas that is heavier than air.  It is commonly stored under high pressure as a liquid.

Phosgene was first produced by John Davy (inventor of the 'Davy Lamp') at the start of the 19th century.  The chemical was named by combining the Greek words 'phos' (meaning light) and genesis (birth), as Davy used sunlight to produce the chemical from carbon monoxide and chlorine. 

Phosgene is an important industrial chemical, with several million tons produced globally each year.  Phosgene gas is produced industrially by reacting carbon monoxide with chlorine over a catalyst at high temperature. The main commercial use of phosgene is in the manufacture of other chemicals such as plastics, pesticides, medicines, dyes and herbicides.

Phosgene is not used domestically and so exposure in the home is unlikely.  However, phosgene can be produced accidentally if solvents containing chlorine are exposed to hot metal surfaces or flames.

As with all chemicals, the health effects of phosgene are related to the concentration to which you are exposed.  Phosgene is categorised as being very toxic and at low concentrations it may cause eye, nose and throat irritation. Exposure to higher concentrations may cause breathlessness and a cough which produces white or yellow sputum.

Delayed, serious lung damage may occur after exposure to high concentrations.  Spills of liquefied phosgene on the skin may cause irritation and burns.  Children may be more sensitive to the effects of phosgene due to their smaller size.  Phosgene is particularly dangerous as exposure may go unnoticed and there may be a delay of several hours before signs of poisoning become apparent.  Therefore, it is very important that anyone who has been potentially exposed to phosgene must be referred to hospital for observation.

People who have been exposed to phosgene generally make a complete recovery, although this may take some months for those exposed to high concentrations.  Smokers and people with existing lung diseases may experience more severe and persistent lung injury.

Phosgene is unlikely to cause harm to the unborn child and is not considered to be a cancer-causing chemical (carcinogen).

Key Points       Production and Uses

• Phosgene - Production and Uses
  Added/updated: 15 October 2008