[barnas2]

Tear gas is illegal to use in war because of a fear of escalation/retaliatory strikes due to an enemy thinking you're using other more dangerous chemical/biological weapons (chlorine, sarin, mustard, phosgene, etc).

It's not banned in war because it's as dangerous as chemical weapons, it's banned in war so people don't think you're using chemical weapons.

[tekknik]

I’d also add that in basic training you’re hit with tear gas so you know what it’s like and learn to trust your equipment. They don’t do that unless there’s a chance you may encounter it.