Tear gas and pepper spray are not the same thing. They cause similar symptoms, including burning eyes, difficulty breathing, and skin irritation, but they come from completely different sources and use different chemicals to produce those effects. The confusion is understandable because both fall under the broad category of “riot control agents” or “lacrimators” (substances that cause tearing). In practice, though, the differences between them matter for how they work, how intense they feel, and how you treat exposure.
What Each One Actually Is
Tear gas is a synthetic chemical compound. The two most common types are CS gas (o-chlorobenzylidene malonitrile) and CN gas (2-chloroacetophenone). CS is the more widely used of the two today, especially by military and law enforcement. These are manufactured in a lab, and in their raw form they’re solids or powders that get dispersed into the air as fine particles or droplets.
Pepper spray, by contrast, comes from chili peppers. Its active ingredient is oleoresin capsicum (OC), an oily extract of hot peppers containing capsaicinoids, the same compounds that make a jalapeño burn your mouth. The concentration of OC in commercial sprays ranges from 1% to 10%, but what really determines potency is the capsaicinoid content. Law enforcement formulas can reach capsaicinoid levels as high as 22%. For reference, police-grade pepper spray rates between 2 million and 5.3 million Scoville heat units, hundreds of times hotter than a habanero pepper.
How They Affect Your Body
Both substances are designed to temporarily incapacitate a person, but they take slightly different routes to get there. Tear gas compounds like CS irritate mucous membranes and nerve endings on contact. When the particles land on your eyes, nose, mouth, or skin, they trigger intense burning, uncontrollable tearing, coughing, and a feeling of chest tightness. The reaction is fast and overwhelming, but it’s primarily a surface-level chemical irritation.
Pepper spray works through the same pain pathways your body uses to detect heat. Capsaicinoids activate receptors that normally respond to high temperatures, which is why OC exposure feels like being burned. It causes immediate swelling of the mucous membranes in the eyes, nose, and throat. The eyes typically slam shut involuntarily, and breathing becomes difficult as airways constrict. The sensation tends to be more intensely painful than CS gas, and people often describe it as feeling like their face is on fire.
One key practical difference: pepper spray is effective on people who are heavily intoxicated or in altered mental states, situations where CS gas sometimes has a reduced effect. This is one reason law enforcement agencies adopted OC spray for individual encounters.
How They’re Delivered
The delivery method is one of the most visible differences between the two. Tear gas is typically deployed as canisters that are thrown, launched from grenade launchers, or fired from specialized guns. Some canisters use a pyrotechnic charge (essentially a small controlled burn) to vaporize the chemical, which means they get extremely hot and can cause fires or thermal burns on contact. The gas disperses over a wide area, making it a crowd-control tool.
Pepper spray is usually a handheld canister, similar to a small aerosol can. It shoots a stream, cone, or fog of liquid OC solution. The range is much shorter, typically 10 to 15 feet, and it’s designed for use against individuals or small groups rather than large crowds. Civilian self-defense sprays use this same basic design in a smaller package. Postal workers in the United States have carried OC spray as a dog repellent since the 1960s, originally at a concentration of just 0.35%.
Legal Status
Here’s where things get interesting. The 1993 Chemical Weapons Convention bans the use of riot control agents, including both tear gas and pepper spray, as a “method of warfare.” That means militaries cannot use them against enemy combatants in armed conflict. The same treaty, however, explicitly permits their use for “law enforcement including domestic riot control purposes.”
The practical result is a legal split: these chemicals are banned on the battlefield but legal on city streets. As Canada’s military code of conduct summarizes it, CS gas and pepper spray “may be used for crowd control purposes, but their use as a means of warfare is illegal.” Australia’s military law manual adds that riot control agents can still be used during wartime for specific purposes like maintaining order in prisoner-of-war camps or managing civilian unrest, just not as weapons against opposing forces.
Within the United States, pepper spray is legal for civilian self-defense in all 50 states, though some states restrict concentration levels or canister size. Tear gas canisters are generally not available to civilians and are restricted to law enforcement and military use.
What to Do if You’re Exposed
The immediate response is similar for both. Move to fresh air, ideally to higher ground, since the aerosol particles from both substances are heavier than air and settle downward. Resist the urge to rub your eyes or face, which only grinds the irritant deeper into your skin and mucous membranes.
For eye exposure, the American Academy of Ophthalmology recommends flushing your eyes with water or saline for 15 to 20 minutes. If you’re wearing contact lenses, remove them before rinsing and throw them away, as they trap chemical particles against the eye. Despite online recommendations, there is no evidence that baby shampoo in the rinse water helps.
For skin, wash thoroughly with soap and water. Remove contaminated clothing carefully, pulling it away from your face rather than over your head, and seal it in a plastic bag to prevent re-exposure. Pepper spray’s oily base can make it slightly harder to wash off than CS gas powder, so you may need to scrub longer.
Most symptoms from either substance resolve within 15 to 30 minutes once you’re away from the source and decontaminated, though skin irritation and eye redness can linger for hours. Heavy or prolonged exposure, especially in enclosed spaces, can cause more serious respiratory problems that need medical attention.
The Bottom Line on Differences
Tear gas and pepper spray share the same purpose (temporary incapacitation through pain and irritation) and the same legal category (riot control agents), but they differ in almost every other way. Tear gas is synthetic, powder-based, deployed over large areas, and primarily used by military and police units. Pepper spray is plant-derived, oil-based, aimed at individuals, and widely available to civilians. Both are banned in warfare but permitted for domestic law enforcement. If you’ve been exposed to either, the decontamination steps are largely the same: get to fresh air, flush your eyes with clean water, and wash your skin with soap.