What does tear gas do?

Tear gas is a term commonly heard in news stories about protests and riots. So, what is tear gas? Essentially, it's a non-lethal chemical weapon designed to cause irritation in the eyes, mouth, throat, and lungs, temporarily incapacitating those exposed to it. Often used for crowd control at larger scales or personal protection at the individual level, tear gas has unfortunately become a household term due to its frequent use in various situations globally.


Three Types Of Tear Gases

Tear gas isn't a single compound but refers to various chemicals that act as tear gas agents, causing similar effects. There are multiple tear gas chemicals available on the market. These include:

  1. CS gas (o-chlorobenzylidenemalononitrile)
  2. CN gas (chloroacetophenone) - often sold under the brand name Mace
  3. OC spray (oleoresin capsicum) - known as pepper spray

CS is a potent agent, producing stronger effects than CN, though its effects wear off more swiftly. Each of these agents operates differently, but all are used to incapacitate or deter individuals through discomfort and irritation.


How Tear Gas Works

When a tear gas canister is deployed, it releases chemical irritants into the air. These agents act quickly, irritating the mucous membranes of the eyes, nose, mouth, and lungs of those in the exposed area. This exposure leads to a series of reactions including tearing, sneezing, coughing, difficulty breathing, runny nose, and in some cases, severe injury and permanent harm like respiratory failure. The intense discomfort forces individuals to flee from the affected area, making tear gas an effective tool for dispersing crowds.


Commonly Used As Riot Control Agents

The use of tear gas is prevalent, particularly in the form of CN or CS, as seen during moments of civil unrest or large protests. Law enforcement agencies often resort to tear gas use when faced with combative or non-compliant crowds. The liquid tear gas is weaponized and launched either as grenades or aerosol cans, turning the liquid into an aerosol that spreads rapidly, affecting a wide area and helping to disperse crowds efficiently.


Geneva Convention and Tear Gas

Interestingly, Geneva banned tear gas in warfare due to its harmful effects. In 1993, the Chemical Weapons Convention also reinforced the 1925 Geneva Protocol. This prohibition on military forces underscores the serious concerns international bodies have about the use of tear gas. However, the domestic use of these crowd control chemicals by law enforcement for riot control purposes is still permitted in many countries.


Risks Associated with Tear Gas Exposure

It’s crucial to understand that exposure to tear gas can be harmful, especially for individuals with preexisting respiratory conditions. These individuals are at higher risk of developing severe symptoms, which may require immediate medical attention. Symptoms like difficulty breathing, blurred vision, and runny nose are common and can be particularly distressing. Even healthy individuals may experience significant discomfort and disorientation upon exposure. After all, tear gas irritates the eyes, skin, and respiratory system.


What To Know About Tear Gas Exposure

Both CN and CS are primarily irritants — they irritate the mucous membranes, causing a cascade of uncomfortable symptoms. Pepper spray, on the other hand, acts as an inflammatory agent, causing swelling and inflammation in the eyes, nose, and mouth, making it more debilitating than its counterparts. However, its effectiveness relies on direct contact, making pepper spray a popular choice for self-defense against individuals, as well as for protection against attacking animals like dogs and bears.


Protecting Yourself From Tear Gas

If you find yourself in a situation where tear gas is deployed, it’s vital to protect yourself from its effects. Move away from the area as quickly as possible, and seek fresh air. If exposure occurs, flush your eyes with water and remove contaminated clothing. Seeking medical attention is crucial if you experience severe reactions or have preexisting health conditions that may exacerbate the effects of tear gas exposure.

With an understanding of what tear gas is and how it works, individuals can better protect themselves and advocate for the responsible and ethical use of these potent chemical agents. This knowledge is especially pertinent given the prevalence of tear gas in various public and private settings, where its use can significantly impact the health and well-being of those exposed.


This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.

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Frequently Answered Questions

Why does tear gas hurt?
The pain caused by tear gas is a result of the chemical irritating the mucous membranes in the eyes, nose, mouth, and lungs.
What tear gas feels like?
Tear gas feels like a burning sensation in the eyes, nose, mouth, and lungs.