These Are the Effects of Tear Gas on the Human Body

Protestors around the country are being met with the substance, which can cause vomiting and choking, among other health problems.

Protesting is an American right; the First Amendment specifically states it as such. So following the death of George Floyd on May 25—and countless others throughout the years—organized protests popped up around the world, with large groups of people assembling in rural and urban areas.

While most of the protests and demonstrations have been peaceful (or intended as such), many have still turned dangerous quickly, with law enforcement meeting protestors with riot gear, rubber bullets, and flash grenades. Tear gas—another riot control agent (RCA)—has also been used in an attempt to break up crowds.

The truth is, a large majority of us may never have to feel the direct effects of tear gas, but it's still important to know how the chemical can affect the human body—and what (if anything) you can do if you do find yourself in that situation. We asked physicians who's most at-risk for suffering from tear gas, what injuries are associated with the substance, and what you should do immediately after being exposed.

What exactly is tear gas?

Riot control agents—again, the technical term for tear gas—may be liquids or solids (fine powders), and include a number of chemical compounds, the most common of which, according to the CDC, are chloroacetophenone (Agent CN) and chlorobenzylidenemalononitrile (Agent CS). Another chemical compound—Agent OC (oleoresin capscium), more widely known as pepper spray, along with its synthetic version PAVA—is also typically grouped into the category of tear gas, per a graphic from the American Civil Liberties Union, based on data from a 2016 report from Physicians for Human Rights (PHR) and the International Network of Civil Liberties Organizations (INCLO).

It's important to know that Agent OC or PAVA and Agent CS aren't necessarily used for the same purposes, and target different bodily systems. Agent OC—commonly used as a personal self-defense tool—targets pain and temperature receptors in the body, causing sensations like burning and severe pain. Agent OC is an oil, and can also penetrate the skin and enter mucous membranes.

Agent CS—most commonly used during protests for crowd-control purposes—dissolves into a painful acidic liquid when it comes into contact with water, sweat, or oil on a person's skin or mucous membranes, per the ACLU. Agent CS is actually a solid white powder that's mixed with a solvent, that is then aerosolized, heated, or exploded to be dispersed through the air.

Also—and definitely not for nothing—tear gas has long been banned from warfare, along with all other chemical weapons, according to the International Committee of the Red Cross (ICRC). However, the use of RCAs in law enforcement is still permitted.

How does tear gas affect the body?

According to the CDC, tear gas specifically targets the the eyes, throat, mouth, skin, and lungs—and it's designed to work fast, causing irritation "within seconds of exposure."

"The first thing that happens [after exposure] is your eyes tear up and become very painful," Diane Calello, MD, executive and medical director of the New Jersey Poison Center and an associate professor of emergency medicine at Rutgers New Jersey Medical School, tells Health. Additionally, tear gas can cause a runny nose, difficulty swallowing, drooling, coughing, chest tightness, wheezing, shortness of breath, rash and burns on the skin, nausea, vomiting, and a choking sensation, per the CDC. And because it typically targets the respiratory tract, tear gas can be especially hard on those with lung or respiratory conditions like asthma.

However, it's not just exposure to the actual substance that can cause harm to the body. "The biggest threat is the canister itself acting as a missile," explains Ian Wittman, MD, chief of emergency medicine at NYU Langone Hospital in Brooklyn, New York. Dr. Wittman adds that these can travel very quickly, and if a tear gas canister hits your eye, it can cause a laceration, leading to blindness or loss of the eye.

If it's aimed at you from a very close distance, the pressure and concentration of the spray itself can also cause damage, Dr. Wittman says. "The large canisters have a pretty high pressure." Those that police forces use can cause significant damage if you're within a few feet of them. He adds that the compounds found in RCAs "can break down tissues of the eye." Dr. Calello also says, if administered close to your face, tear gas can result in a corneal burn, although rarely.

A 2016 report published in Annals of the New York Academy of Sciences echoes the claim that tear gas is especially threatening if used up close. Deaths and severe injuries have been reported as a result of "massive-scale deployments of tear gas munitions," the report says. "These were often caused by direct or close impact of tear gas munitions causing severe head and eye injuries and burns." (Also worth noting: the Annals of the New York Academy of Sciences paper says the United States is among a number of countries in which "tear gas use has dramatically increased in recent years.")

Of course, many injuries related to RCAs stem not from the actual agents themselves but from the rush to get away from them. People trying to evade tear gas that's sprayed into a crowd can end up falling, getting stepped on in that crowd, or sustaining other injuries.

How can you protect yourself against tear gas—and what can you do if you've been exposed?

There's really only one thing you can do to protect yourself if you're in a situation with RCAs: get away from the gas. The CDC says it's important to move to an area where fresh air is available. That's usually to higher ground, because the gas is denser than the air, and will sink closer to the ground. And if you're inside a building where tear gas has been deployed, get out ASAP.

Also important for contact-wearers: Dr. Witmann recommends removing your contact lenses before you go to a protest (wearing glasses may also help reduce your exposure, though they won't protect you completely). And if you are exposed while while wearing your contacts, the CDC says you should not put them back into your eyes even if they're not the disposable kind.

After you're a safe distance away from the tear gas, the CDC recommends following a few simple steps to minimize your suffering:

  • Remove affected clothing as quickly as possible. The CDC says there's a specific way to do this: "Any clothing that has to be pulled over the head should be cut off the body instead of pull over the head."
  • Wash your body. You'll want to rinse your body with soap and water to remove any tear gas residue from your skin. If your vision is blurry, rinse your eyes with water.
  • Throw away your affected clothing. For your safety, you don't want to wash and re-wear those clothes, so the CDC suggests putting them in a sealed plastic bag inside of another plastic bag (while wearing plastic gloves or using tongs), then place the bags outside for your state health department to dispose of.

While you're at it, don't bother applying any techniques you've seen online to "neutralize" exposure. "There is inconclusive evidence to support the use of milk, vaseline, or other remedies to prevent or treat the effect of tear gas exposure," Dr. Calello adds.

Any severe pain that persists half an hour after exposure should prompt you to see a doctor, as should vision loss that continues on after the initial exposure, says Dr. Wittman. And if you experienced any other injuries from tear gas exposure at a protest—like getting hit with a projectile canister or find yourself experiencing difficulty breathing or chest pain—it's a good idea to get medical attention ASAP.

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