Chlorine gas is yellow-green colored and has a strong smell similar to bleach. Like phosgene, it is a choking agent, which obstructs breathing and damages tissues in the body. It can easily be pressurized and cooled to liquid state so that it can be shipped and stored. Chlorine spreads quickly and stays close to the ground because it is heavier than air. Though it is less lethal than other chemical agents, chlorine is dangerous because it’s easy to manufacture and disguise.

Special mention: Riot control agents

While not strictly banned by the CWC (it doesn’t apply to domestic law enforcement), riot control agents have often been used with devastating effects. Their temporary effects include crying, uncontrollable blinking, burning in the throat, sneezing, coughing, vomiting, and at times temporary blindness.

This first appeared in 2014.