My first thought as well
Straight to comments , first thought as well. Second thought was , iinnant that juss too effin’ bad.
It is a poison gas of sorts, ie it’s noxious, harmful to inhale, makes you incapable of normal breathing, it is meant to have a negative physical effect. So you expect no aftereffects? Leaving even within an hour, tear gas is not “two breaths” out of your system.