PAVA spray

PAVAPAVA incapacitant sprayPAVA/OC
British police forces have traditionally used CS gas spray. More recently, some forces have opted to use PAVA. Both PAVA and CS are prohibited under Section 5 of the Firearms Act 1968 as a: "weapon of whatever description designed or adapted for the discharge of any noxious liquid, gas or other thing", meaning that it is unlawful for a member of the public to possess them. Police officers, and other servants of the Crown, have lawful exemption to possess and use PAVA.

Pepper spray

OC sprayoleoresin capsicumpepper-sprayed
Some of the OC and CS will remain in the respiratory system, but a recovery of vision and the coordination of the eyes can be expected within 7 to 15 minutes. Some "triple-action" pepper sprays also contain "tear gas" (CS gas), which can be neutralized with sodium metabisulfite (Campden tablets, used in homebrewing), though it is not water-soluble either and must be washed off using the same procedure as for pepper spray. Pepper spray antidotes exist; examples include capsazepine, ruthenium red, and other TRPV1 antagonists. Pepper spray typically comes in canisters, which are often small enough to be carried or concealed in a pocket or purse.

Riot control

riot control agentriot geartear gas
CS gas. Long Range Acoustic Device. Pepper spray. Rubber bullet. Water cannon. Pellet guns (pellet shotguns). Use of bayonets for crowd control.

CR gas

dibenzoxazepinedibenz (b,f)-1,4-oxazepine (CR gas)dibenz[''b,f''][1,4]oxazepine
CS gas. Oxazepine. Pepper spray. Tear gas.

Gas mask

gas masksgasmaskgas-mask
During demonstrations and protests where tear gas or CS gas is employed by riot police, gas masks are commonly used by police and demonstrators alike. Aside from serving their functional purposes, gas masks are also used as emblems in industrial music, with the most notable example, the subgenre of drum and bass called neurofunk. These emblems are used by graffiti taggers because the mask protects them from the paint canister's toxic fumes, and by urban explorers venturing into environments where hazardous materials, such as asbestos, may be present.

Phenacyl chloride

CN gasCNChloroacetophenone
Because of its significantly greater toxicity, it has largely been supplanted by CS gas. Even though CN is still supplied to paramilitary and police forces in a small pressurized aerosol known as “Mace” or tear gas, its use is falling as pepper spray both works and disperses more quickly than CN and is less toxic than CN. The term "Mace" came into being because it was the brand-name invented by one of the first American manufacturers of CN aerosol sprays. Subsequently, in the United States, Mace became synonymous with tear-gas sprays in the same way that Kleenex has become strongly associated with facial tissues (a phenomenon known as a genericized trademark).


Bromoacetone is an organic compound with the formula 3 CCH 2. This colorless liquid is a lachrymatory agent and a precursor to other organic compounds.

2014 Hong Kong protests

Umbrella Revolution2014 Occupy protests2014 protests
The police confirmed that they fired tear gas 87 times. At least 34 people were injured in that day's protests. According to police spokesmen, officers exercised "maximum tolerance", and tear gas was used only after protesters refused to disperse and "violently charged". The South China Morning Post (SCMP) reported, however, that police officers were seen charging the suffragists. The media recalled that last time Hong Kong police used tear gas had been on Korean protesters during the 2005 World Trade Organization conference.

2019 Hong Kong protests

2019 Hong Kong anti-extradition bill protestsHong Kong protestsprotests
The police were found to have been using tear gas as an offensive weapon, firing it indoors inside a railway station, and using expired tear gas, which could release toxic gases upon combustion. The usage of tear gas sparked public health concerns as approximate 10,000 volleys of gas have been fired since June. Chemical residues were found on different public facilities in various neighbourhoods, and a reporter was diagnosed with chloracne following sustained exposure to tear gas, but the government refused to disclose the chemical composition of the gas, citing "operational concerns".


policingpolice forcepolice department
Non-lethal weapons include batons, tear gas, riot control agents, rubber bullets, riot shields, water cannons and electroshock weapons. Police officers typically carry handcuffs to restrain suspects. The use of firearms or deadly force is typically a last resort only to be used when necessary to save human life, although some jurisdictions (such as Brazil) allow its use against fleeing felons and escaped convicts. A "shoot-to-kill" policy was recently introduced in South Africa, which allows police to use deadly force against any person who poses a significant threat to them or civilians.

Chemical weapon

chemical weaponspoison gaschemical
The Holocaust resulted in the largest death toll to chemical weapons in history., CS gas and pepper spray remain in common use for policing and riot control; while CS is considered a non-lethal weapon, pepper spray is known for its lethal potential. Under the Chemical Weapons Convention (1993), there is a legally binding, worldwide ban on the production, stockpiling, and use of chemical weapons and their precursors. Notwithstanding, large stockpiles of chemical weapons continue to exist, usually justified as a precaution against putative use by an aggressor.

Waco siege

WacosiegeBranch Davidian siege
The court found that the government's planning of the siege—i.e., the decisions to use tear gas against the Branch Davidians; to insert the tear gas by means of military vehicles; and to omit specific planning for the possibility that a fire would erupt—was a discretionary function for which the government could not be sued. The court also found that the use of tear gas was not negligent.

Non-lethal weapon

non-lethalless-lethalnon-lethal weapons
The use of chemical weapons such as tear gas (CS) and pepper spray (OC) has come under increasing scrutiny and criticism due to studies showing serious long term side effects. Many police forces are no longer exposing their members to the chemicals during training. Journalist Rubén Salazar was killed in Los Angeles in 1970 by an errant CS gas canister during the Chicano riots. Other serious injuries and fatalities have occurred from either tear gas itself or the projectiles it is delivered in, including the critical injury of veteran Scott Olsen from a tear gas canister during the 2011 Occupy Oakland protests.

Police uniforms and equipment in the United Kingdom

uniformbobbiesBritish Metropolitan Police
Officers may carry either a CS or PAVA (also known as Captor) incapacitant spray. Their effects are designed to be short-lived and exposure to fresh moving air will normally result in a significant recovery within 15–20 minutes. The CS spray issued by UK police services contains a 5% solution of CS whilst Captor sprays contain a 0.3% solution of PAVA. PAVA is significantly more potent than CS. Aerosol incapacitants are classified as prohibited weapons by virtue of Section 5 of the Firearms Act 1968 and possession of such sprays is therefore illegal by the general public. They may only be possessed with the authority of the Defence Council or the Scottish Ministers.

Mónica Kräuter

She stated that the majority of canisters used the main component CS gas, supplied by Cóndor of Brazil, which meets Geneva Convention requirements, but that 72% of the tear gas used was expired and other canisters produced in Venezuela by Cavim did not show adequate labels or expiration dates. Following the expiration of tear gas, she notes that it "breaks down into cyanide oxide, phosgenes and nitrogens that are extremely dangerous". Kräuter has advised against the use of vinegar to neutralize the effects of tear gas since it is an acid, instead recommending the use of sodium bicarbonate or antacids such as Maalox.


hand grenadegrenadeshand grenades
Tear gas grenades are similar to smoke grenades in shape and operation. In tear gas grenades, the filler is generally 80 to 120 g of CS gas combined with a pyrotechnic composition which burns to generate an aerosol of CS-laden smoke. This causes extreme irritation to the eyes and, if inhaled, to the nose and throat. They were used in the Waco Siege. Occasionally CR gas is used instead of CS. Incendiary grenades (or thermite grenades) produce intense heat by means of a chemical reaction. Seventh-century "Greek fire" first used by the Byzantine Empire, which could be lit and thrown in breakable pottery, could be considered the earliest form of incendiary grenade.


aerosolsaerodynamic diameteratomization
An aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants and The liquid or solid particles have diameters typically

Nerve agent

nerve gasnerve agentsnerve gases
Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase, an enzyme that catalyzes the breakdown of acetylcholine, a neurotransmitter.

Amnesty International

AmnestyAmnesty International UKAmnesty International Norway
Amnesty International (commonly known as Amnesty or AI) is a non-governmental organization based in the United Kingdom focused on human rights. The organization claims it has more than seven million members and supporters around the world.


Transient receptor potential cation channel, member A1TRPA1 channel
TRPA1 knockout mice showed near complete attenuation of nocifensive behaviors to formalin, tear-gas and other reactive chemicals. TRPA1 antagonists are effective in blocking pain behaviors induced by inflammation (complete Freund's adjuvant and formalin). Although it is not firmly confirmed whether noxious cold sensation is mediated by TRPA1 in vivo, several recent studies clearly demonstrated cold activation of TRPA1 channels in vitro. In the heat-sensitive loreal pit organs of many snakes TRPA1 is responsible for the detection of infrared radiation.

Bahraini uprising of 2011

Bahraini uprisingBahraini uprising (2011–present)2011 Bahraini protests
On 13 March, the government reacted strongly, with riot police firing tear gas canisters and tearing down protest tents in the Pearl Roundabout and using tear gas and rubber bullets to disperse demonstrators in the financial district, where they had been camping for over a week. Witnesses reported that riot police were encircling Pearl Roundabout, the focal point of the protest movement, but the Ministry of Interior said they were aiming to the open the highway and asked protesters to "remain in the [Pearl] roundabout for their safety". Thousands of protesters clashed with police forcing them to retreat.

Branch Davidians

Branch DavidianBranch Davidian Seventh-Day Adventist ChurchBranch Davidian Seventh Day Adventist
The FBI attempted to use tear gas to flush out the Branch Davidians without bloodshed. Officially, FBI agents were only permitted to return any incoming fire, not to actively assault the Branch Davidians. When several Branch Davidians opened fire, the FBI's response was to increase the amount of gas being used. Around noon, three fires broke out simultaneously in different parts of the building, The government maintains the fires were deliberately started by Branch Davidians. Some Branch Davidian survivors maintain that the fires were started either accidentally or deliberately by the assault.

Demonstration (political)

demonstrationsdemonstrationprotest march
Police and military authorities often use non-lethal force or less-lethal weapons, such as tasers, rubber bullets, pepper spray, and tear gas against demonstrators in these situations. Sometimes violent situations are caused by the preemptive or offensive use of these weapons which can provoke, destabilize, or escalate a conflict. As a known tool to prevent the infiltration by agents provocateurs, the organizers of large or controversial assemblies may deploy and coordinate demonstration marshals, also called stewards. Freedom of assembly in Brazil is granted by art. 5th, item XVI, of the Constitution of Brazil (1988): Constitution of Brazil – Text in English.

Chemical Weapons Convention

CWCChemical Weapons TreatyConvention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction
Tear gas. Full text of the Chemical Weapons Convention, OPCW. Online text of the Chemical Weapons Convention: Articles, Annexes including Chemical Schedules, OPCW. Fact Sheets, OPCW. Chemical Weapons Convention: Ratifying Countries, OPCW. Chemical Weapons Convention Website, United States. The Chemical Weapons Convention at a Glance, Arms Control Association. Chemical Warfare Chemicals and Precursors, Chemlink Pty Ltd, Australia.

People's Park (Berkeley)

People's ParkBloody ThursdayJames Rector
The editorial offices of Berkeley Tribe were sprayed with pepper gas and had tear gas canisters fired into the offices, injuring underground press staff. On May 20, 1969, National Guard helicopters flew over the Berkeley campus, dispensing airborne tear gas that winds dispersed over the entire city, sending school children miles away to hospitals. This was one of the largest deployments of tear gas during the Vietnam era protests. Governor Reagan would concede that this might have been a "tactical mistake." It had not yet been banned from warfare under the Chemical Weapons Convention.