[photo/encrypted-tbn0.gstatic.com/teargasimages]Tear gas is derived from the Latin word lacrima, meaning "tear".
It's a biochemical weapon that causes severe eye, respiratory, and skin irritation, pain, vomiting, and even blindness. In the eye, it stimulates the nerves of the lacrimal gland to produce tears.
This includes injuries from being hit by tear gas cartridges, which include severe bruising, loss of eyesight, skull rupture, and even death.
While the medical concerns of the gases themselves are typically limited to minor skin inflammation, overdue complications are also possible: people with pre-existing breathing conditions such as asthma, who are most at risk, are likely to need medical consideration and may occasionally require hospitalization or even ventilation support.
Skin contact to CS may cause chemical burns or bring allergic contact dermatitis.
When people are hit at close by range or are severely unprotected, eye damages involving scarring of the cornea can lead to a permanent loss of visual acuity.