Tear gas

Tear gas is the name for a number of chemical compounds.  They are not actually gases.  They are fine powders or mists of liquid.  The chemicals are acidic and cause  pain in the eyes.  Tear gas may cause temporary blindness for up to 45 minutes.  Tear gas is commonly used by police to control crowds.  Phenacyl chloride (CN) liquid and CS powder are two of the chemicals that are often found in tear gas.  Pepper spray is another chemical compound that acts very similarly and is sometimes used to control crowds.

Tear gas is a chemical weapon, and was used as a weapon in the First World War.  The 1925 Geneva Protocol is not specific enough about the use of irritating agents, such as tear gas in war.  The Chemical Weapons Convention, of 1992 prohibits the use of tear gas for warfare.  The use as a riot control agent is not covered by the treaty.

 Problems of using tear gas 
The use of tear gas also has problems: Usually, cartidges of tear gas are thrown; they can hit and injure people. A case of serious injury to the blood vessels from tear gas shells has also been reported from Iran, with high rates of associated nerve injury (44%) and amputation (17%), as well as instances of head injuries in young people. Directly exposing skin to tear gas may lead to chemical burns and allergic reactions of the skin.

In the short term, the medical consequences are usually limited to  skin inflammation. delayed complications are also possible: people with respiratory conditions such as asthma are likely to need medical attention and may sometimes require hospitalization or even ventilation support. Skin exposure to CS may cause chemical burns or induce allergic contact dermatitis. When people are hit at close range or are severely exposed, eye injuries involving scarring of the cornea can lead to a permanent loss in visual acuity. Frequent or high levels of exposure carry increased risks of respiratory illness.

 References 

 Related pages 
 Chemical warfare

 Other websites
 Riot Agents 

Category:Chemical warfare
Category:Law enforcement equipment
Category:Chemicals