Use of tear gas has become increasingly common over the past several decades. Law enforcement agencies in the United States, Hong Kong, Greece, Brazil, Venezuela, Egypt, and other areas use it to control riots and disperse crowds.

A 2013 review of research found that clinically significant health complications from tear gas are uncommon. However, there’s still debate surrounding its acceptable use.

Some people feel more research is needed to better assess its safety. Children and people with respiratory complications may be at a heightened risk of developing complications when exposed to tear gas.

In this article, we’ll look at how tear gas affects human health and what you can do if you’re exposed to it.

Tear gas is a collection of chemicals that cause skin, respiratory, and eye irritation. It’s usually deployed from canisters, grenades, or pressurized sprays.

Despite the name, tear gas isn’t a gas. It’s a pressurized powder that creates a mist when deployed. The most commonly used form of tear gas is 2-chlorobenzalmalononitrile (CS gas). It was first discovered by two American scientists in 1928 and the U.S. Army adopted it for controlling riots in 1959.

Other common types of tear gases include oleoresin capsicum (pepper spray), dibenzoxazepine (CR gas), and chloroacetophenone (CN gas).

Tear gas was used as a chemical weapon in World War I. However, it’s currently illegal for wartime use. In 1993, many of the world’s countries came together in Geneva to sign an international treaty to prevent chemical warfare. Article I(5) of the treaty states, “Each State Party undertakes not to use riot control agents as a method of warfare.”

Almost every country signed the treaty except for four U.N. member states: North Korea, South Sudan, Egypt, and Israel.

Contact with tear gas leads to irritation of the respiratory system, eyes, and skin. The pain occurs because the chemicals in tear gas bind with one of two pain receptors called TRPA1 and TRPV1.

TRPA1 is the same pain receptor that the oils in mustard, wasabi, and horseradish bind to give them their strong flavors. CS and CR gas are more than 10,000 times more potent than the oil found in these vegetables.

The severity of the symptoms you experience after exposure to tear gas can depend on:

  • whether you’re in an enclosed space or an open space
  • how much tear gas is used
  • how close you are to the tear gas when it’s released
  • whether you have a preexisting condition that may be exacerbated

Most people recover from tear gas exposure without any significant symptoms. A 10-year study performed at University of California San Francisco examined 4,544 cases of pepper spray. Researchers found a 1 in 15 chance of developing severe symptoms after exposure.

Some of the potential effects of tear gas exposure include:

Eye symptoms

Immediately after exposure to tear gas, you can experience the following eye symptoms:

Long-term exposure or exposure at a close range can lead to:

Respiratory and gastrointestinal symptoms

Breathing in tear gas can cause irritation of your nose, throat, and lungs. People with preexisting respiratory conditions have a higher risk of developing severe symptoms such as respiratory failure.

Respiratory and gastrointestinal symptoms include:

In severe cases, exposure to high concentrations of tear gas or exposure in enclosed spaces or for a prolonged period of time can lead to death.

Skin symptoms

When tear gas comes into contact with exposed skin, it can lead to irritation and pain. The irritation can last for days in severe cases. Other symptoms include:

Other tear gas symptoms

According to Physicians for Human Rights, prolonged or repeated exposure to tear gas can cause symptoms of post-traumatic stress disorder (PTSD).

Tear gas exposure can lead to increased heart rate or blood pressure. In people with preexisting heart conditions, this can lead to cardiac arrest or death.

Getting hit by a tear gas canister can lead to a traumatic injury.

Some animal research suggests that exposure to CS gas may increase the risk of having a miscarriage or cause fetal abnormalities. However, there isn’t enough human research at this time to know how CS gas affects fetal development in humans.

There’s no antidote for tear gas, so treatment relies on managing individual symptoms.

According to the Centers for Disease Control and Prevention, you should immediately move away from the source of tear gas after exposure and seek fresh air. Vapor from tear gas settles to the ground, so it’s a good idea to seek high ground if possible.

It’s also a good idea to remove clothing that may have been contaminated and bathe with soap and water to get the vapors off your skin.

You can clear your eyes by flushing them with water until you completely get rid of the tear gas.

Complications of tear gas can get worse the longer you’re exposed. Minimizing the amount of time you’re in contact with the gas by moving away as quickly as possible can minimize your risk of developing more severe side effects.

You may be able to minimize your exposure by covering your eyes, mouth, nose, and skin as much as possible. Wearing a scarf or bandana over your nose and mouth may help prevent some of the gas from entering your airways. Wearing goggles can help protect your eyes.

Most people who are exposed to tear gas don’t develop any long-term effects, but in some cases, exposure to tear gas can cause severe complications or death.

If you’re exposed to tear gas, you should seek medical attention immediately so that you can be monitored by a medical professional.

Tear gas is commonly used by law enforcement to control riots and crowds. It’s generally considered a low-risk way to manage riots, but there’s still some debate about when it should be used.

Most people recover from tear gas without complications. However, people exposed to large doses or who have preexisting medical conditions may develop severe symptoms such as respiratory failure, blindness, and even death.

If you’re exposed to tear gas, immediately contact a medical professional to get proper treatment.