Also, somethings to consider: Which tear gas is being used? At what concentration or exposure period can tear gas become fatal? Are you in an enclosed space or outside? Everything I can find says that tear gas is an effective riot control substance and that long term effects or death is the exception and not the rule.
https://www.healthline.com/health/tear-gas-effects#seeking-help
https://pubmed.ncbi.nlm.nih.gov/24379300/
Also, there is conversation that the use of tear gas was banned by the military. This is partially true but is also misleading. The 1993 UN Chemical Weapons Convention dealt with all chemical weapons being used for warfare, and warfare only. Tear gas was addressed but was stated that gases used for riot control are not allowed in warfare. It didn’t ban the substance, just the usage to eliminate the wiggle room of using some horrible gas during warfare and claiming it was used for riot control.
https://ihl-databases.icrc.org/customary-ihl/eng/docs/v2_rul_rule75
But here’s a thought! Why are we worrying about people that want to riot, loot, vandalize, assault others, use weapons, rape and kill? Why is there a view point that they are the poor victims in all of this instead of the instigators? If they weren’t completely out of control and threatening society and human life, tear gas would not be used. Let’s get back to the start of all this instead of trying to question the reaction to the crimes.