Ammonium Nitrate Chemistry

Pepper spray isn’t just a chemical – it’s a chemical weapon

Last week I wrote about pepper spray and other tear gas chemicals, in a story that appeared in The ConversationSBS News, and elsewhere.

Most people accept that law enforcement should have access to tear gas as a form of less-lethal self defense and for riot control. So why is it banned in wartime and why is it so troubling that nations might be using tear gas without justification?

Chemical weapons emerged during World War I, and were used by all sides. Not knowing which chemicals were effective in warfare, just about every harmful substance was tried. The effects were unpredictable and horrific but far from effective in a military sense.

Following World War I it was clear that the only way to prevent chemical warfare escalating was to ban the use of all chemical agents on the battlefield. This was proven during the Vietnam War. History repeated as the US pushed back at the boundaries on chemical weapon bans outlined by the the Geneva Protocol in the 1920's. 

Now we have a robust yet imperfect system of chemical weapons control, underpinned by the Chemical Weapons Convention and the Organisation for the Prohibition of Chemical Weapons (OPCW).

Over a century after WWI, nations continue to use chemical weapons, and unfortunately they are now using them against their own people.

Sarin and chlorine gas have been deployed in the Syrian civil war. Russia used a novel "Novichok" nerve agent to poison a former military officer in the UK. On Russian soil, over 200 hostages were killed in 2002 when a chemical agent was used against Chechen separatists. 

Yes, tear gas is less-lethal. But unjustified use of tear gas on civilians makes it that much more difficult to rid the world of the most deadly chemical weapons.

Chemical formulas for tear gas compounds