Tear gas is meant to be a non-lethal crowd dispersing agent. But to its victims, and the people who study it, that distinction isn't always so clear. As Dr. Jordt told National Geographic, the legacy of tear gas doesn't always live up to that non-lethal claim:

There are enough examples where people suffered severe injury and burns, especially in enclosed environments or city streets with several-story buildings. Residents who live near Tahir Square in Cairo that have gotten a lot of tear gas have had long-term exposure, leading to respiratory problems. Long-term exposure is very problematic.

People with asthma or other conditions can have very severe reactions. Tear gases are very serious chemical threats. I think it is very problematic to use them.


When asked by National Geographic if tear gas should be used on civilians, Dr. Jordt's response was telling:

Tear gas under the Geneva Convention is characterized as a chemical warfare agent, and so it is precluded for use in warfare, but it is used very frequently against civilians. That's very illogical.


It's unknown how many canisters of tear gas have been fired in Ferguson, Missouri. Media reports have been limited, but by all accounts the Ferguson police are relying on it extensively to control and subdue protestors. Given the mixed history of this weapon, and its potential for injury or death, it makes an already unstable situation even more troubling.

Image: Police advance through smoke, Wednesday, Aug. 13, 2014, in Ferguson, Mo. (AP Photo/Jeff Roberson)