The Encyclopedia is a project of the Geneva Academy of International Humanitarian Law and Human Rights launched on 2 December 2013. The Enyclopedia aims to provide accurate, up-to-date information on weapons, the effects of their use, and their regulation under public international law, in a format that is accessible to non-specialists.+ Find out more
The most common chemicals used in law enforcement include o-Chlorobenzylidene Malononitrile (CS), Chloroacetophenone (CN), and Dibenz(b,f)-1,4-oxazepine (CR), which are often referred to as ‘tear gases’, and oleoresin capsicum (OC) and pelargonic acid vanillylamide (PAVA) which are often referred to as ‘pepper sprays’. OC is naturally derived from the capsicum species of plant (such as chilli peppers) whereas PAVA is a synthetic formulation of one of the active ingredients in OC. Other less commonly used irritants or ‘tear gases’ include N-nonanoylmorpholine (MPK/MPA) which is manufactured predominantly in the Russian Federation and Ukraine, and Diphenylaminearsine (DM, or Adamsite).
Methods of dispersal vary and can range from highly targetable handheld sprays to more indiscriminate forms such as launched projectiles or via water cannon.
Use of RCAs is widespread. In 2011, of the 190 states parties to the 1992 Chemical Weapons Convention (CWC), 111 have declared holdings of CS; 67 of CN; 25 of Capsaicinoids (‘pepper sprays’); 11 of CR; and 15 of ‘other types’ [undefined].Report of the OPCW on the Implementation of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction in 2011. The Organisation for the Prohibition of Chemical Weapons (OPCW) does not report which states have declared these holdings. Of the six states not bound by the CWC in 2012 (Angola, the Democratic People’s Republic of Korea, Egypt, Israel, Myanmar, and South Sudan), evidence suggests that all six are in possession of, or have used in the past, a range of RCAs.See, e.g., ‘Israeli Soldiers Use Tear Gas, Stun Grenades to Evict Palestinian Camp’, Russia Today, 2 February 2013; ‘Riot Police Break Up Myanmar Copper Protest’, Al Jazeera, 29 November 2012; Chosun Media, ‘N. Korea Imports Chinese Riot Gear’, 22 June 2011; ‘South Sudan: Civil Unrest and State Repression: Human Rights Violations in Wau, Western Bahr El Ghazal State’, Amnesty International Report, AFR 65/001/2013, 2013.
The 1992 Chemical Weapons Convention (CWC) prohibits use of RCAs as a method of warfare.Art. I(5), 1992 Chemical Weapons Convention. They are, however, permitted for use for ‘law enforcement including domestic riot control’,Art. II(9)(d). as long as 'the types and quantities are consistent with such purposes’.Art. II.1(a).
All states parties to the Convention are obliged to declare the chemical name, structural formula, and Chemical Abstracts Service (CAS) registry number of all chemicals in their possession that are used for riot control purposes.Art. III(1)(e).
According to the OPCW, there was much debate at the time of drafting as to the inclusion of, or level of restrictions to be placed upon, RCAs. The current status of RCAs under the CWC is a compromise which was reached by the negotiating states OPCW, ‘Riot Control Agents’, undated but accessed in October 2013. and, as such, further guidance for states parties on the permissible development, production, stockpiling, and use of RCAs for law enforcement purposes is limited.
In addition, the term ‘method of warfare’ under Article I(5) is not formally defined in the Convention and the OPCW’s policy-making bodies have not issued an interpretation of this rule. Under international humanitarian law, a method of warfare refers to the use of a weapon in the conduct of hostilities. One state party – the United States of America (US) – maintains that ‘RCAs can be legitimately used for a range of non-offensive actions, by military forces present in certain areas of armed conflict’.M. Crowley, ‘Regulation of Riot Control Agents and Incapacitants under the Chemical Weapons Convention’, Research Paper, 2011. Reportedly, however, the USA used CS gas in its cave-clearing operations in Afghanistan.J. Fry, ‘Contextualized Legal Reviews for the Methods and Means of Warfare: Cave Combat and International Humanitarian Law’, Columbia Journal of Transnational Law, Vol. 44 (2006), pp. 506–09, citing: M. Bahmanyar, Afghanistan Cave Complexes 1979–2004: Mountain Strongholds of the Mujahideen, Taliban and Al Qaeda, 2004.
Under Article 7 of the CWC, all states parties are obligated to ‘adopt the necessary measures to implement its obligations’ under the Convention. This, in part, means enacting new national legislation, or strengthening current national legislation, in order to fulfil their treaty obligations. Relevant national legislation prohibiting the use of RCAs as a method of warfare has been collated by the International Committee of the Red Cross (ICRC) in its study of customary international humanitarian law: ‘Practice Relating to Rule 75: Riot Control Agents’.
The 1925 Protocol for the Prohibition of the Use of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare (1925 Geneva Gas Protocol) prohibits its 137 states parties from using RCAs during an international armed conflict. None of these states parties entered a reservation or declaration of interpretation limiting the scope of the Protocol in terms of the types of chemical weapons to which it applies at time of ratification or accession.Ibid. Further, of the six states that have not ratified the CWC, only Myanmar and South Sudan are not formally bound by this Protocol.
Customary international humanitarian law (IHL) refers to international obligations arising out of established and consistent state practice. According to the 2005 International Committee of the Red Cross (ICRC) study of customary IHL, the prohibition of the use of RCAs as a method of warfare is a rule of customary international law.
Although no international human rights law instrument specifically regulates the development, production, stockpiling, and use of RCAs for law enforcement purposes, human rights law is certainly applicable to the employment of such weapons, especially in its regulation of the use of force by law enforcement officials and other agents of the state.
While several human rights norms may be applicable to the regulation of RCAs, the right to life, freedom from torture and cruel, inhuman or degrading treatment, the right to engage in ‘peaceful protest’, and the right to health, together with attendant obligations on the restraint of force, are the most relevant. Consequently the application of international and regional treaties covering these rights, including the International Covenant on Civil and Political Rights, the UN Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, the African Charter on Human and People’s Rights, the European Convention for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment, and the Inter-American Convention Prevent and Punish Torture, need to be examined.For further discussion see M. Crowley, ‘The Use of Riot Control Agents in Law Enforcement’, Chapter 11 in S. Casey-Maslen (ed.) Weapons Under International Human Rights Law, Cambridge University Press, January 2014.
In addition, of particular relevance are two international normative agreements that codify the rules by which law enforcement personnel should operate but which are not legally binding per se: the 1990 Basic Principles on the Use of Force and Firearms by Law Enforcement Officials (BPUFF) and the 1979 Code of Conduct for Law Enforcement Officials. Although the prohibition on torture and other cruel, inhuman or degrading treatment or punishment has long been considered customary international law, the extent to which the BPUFF and the Code of Conduct reflect customary law is not finally settled.
The BPUFF provides that the ‘development and deployment of non-lethal incapacitating weapons should be carefully evaluated in order to minimize the risk of endangering uninvolved persons’ and that ‘the use of such weapons should be carefully controlled’ (Principle 3). The BPUFF also requires that, ‘whenever the lawful use of force and firearms is unavoidable, law enforcement officials shall:
The Council of the European Union (EU) Common Position 2008/944/CFSP defining common rules governing control of exports of military technology and equipment (hereafter, ‘Common Position’), requires all member states to ‘assess the export licence applications made to it for items on the EU Common Military List … on a case by case basis’.Art. 1. A range of common RCAs such as CS, CR, and CN are covered under category ML7(d)(1)–(6) of the EU Common Military List and their dispersal systems are covered under ML7(e)(1). However, ML7 does not currently include OC or PAVA. All EU member states are legally bound by the Common Position.
Furthermore, Article 5 of the European Council Regulation No. 1236/2005 concerning trade in certain goods which could be used for capital punishment, torture or other cruel, inhuman or degrading treatment or punishment (hereafter, ‘Council Regulation’), requires an export authorisation be issued for ‘substances for the purpose of riot control or self-protection and related portable dissemination equipment’ which are listed in Annex III of the Regulation irrespective of the origin of such goods. This Annex covers OC and PAVA and their related dispersal equipment only. As per the Common Position, all EU member states are legally bound by this Regulation and their national legislation should reflect, or contain stronger versions of, the provisions set out in the Regulation.
Currently, no regional treaties or instruments fully regulate the development, production, stockpiling, and use of RCAs for law enforcement purposes.
In accordance with Article 7 of the 1992 Chemical Weapons Convention, all states parties are required to enact national legislation to implement the provisions of the Convention. In addition, EU member states must implement national legislation in accordance with EC Regulation 1236/2005, and Article 12 of the Common Position.
Outside of the EU, some states have their own national legislation controlling the trade in RCAs. The US, for example, has a relatively strong export control regime; however it is overly complex and as a result controls the trade in RCAs under two different lists administered by two different departments.S. 6 of the Export Administration Act of 1979 (as amended) implements the Commerce Control List which is administered by the Bureau of Industry and Security (Department of Commerce); the International Traffic in Arms Regulations controls the United States Munitions List which is administered by the Directorate of Defense Trade Controls (Department of State).
The 1979 Export Administration Act controls chemical agents including tear gas formulations containing 1% or less of CS, CN or liquid pepper except when packaged in ‘individual containers with a net weight of 20 grams or less’ [CN/CS] or in ‘individual containers with a net weight of 3 ounces (85 grams) or less’ [liquid pepper]. The International Traffic in Arms Regulations control 13 different agents including: CN, CR, CS and Adamsite / DM but does not control formulations containing 1% or less of CN or CS, or individually packaged tear gases or riot control agents for personal self-defence purposes, or liquid pepper.
Despite these relatively strong controls, information on national controls and standard operating procedures relating to the use of RCAs by law enforcement officials in the US is difficult to obtain.
The Alien Tort Claims Act is set out under Title 28 §1350 of the United States Code to allow the district courts of the US to ‘have original jurisdiction of any civil action by an alien for a tort only, committed in violation of the law of nations or a treaty of the United States’ (US GPO (2010)). The Alien Tort Claims Act has the potential to be a powerful tool for non-US citizens to seek redress for human rights violations through the US court system.
In 1991, the case of Abu-Zeineh vs. Federal Laboratories Inc. was brought to court under the Alien Tort Claims Act. The plaintiff, a relative of a Palestinian who died after Israeli troops used US-made CS gas in a confined workplace, sued Federal Laboratories for wrongful death after they ‘allegedly sold gas to Israel with the knowledge that [the] gas caused many civilian deaths’.A. Fagan (ed.) Human Rights & Peace Law Docket 1945-1993, Meiklejohn Civil Liberties Institute Archives, 2013. This case was dismissed as the plaintiffs were stateless and therefore had no ‘foreign citizenship for the purposes of diversity jurisdiction’ in US federal courts.US District Court for the Western District of Pennsylvania, Abu-Zeineh v. Federal Laboratories, Inc., Case No. Civ. A. No. 91-2148, 975 F.Supp. 774, 7 December 1994; and S. Joseph, Corporations & Transnational Human Rights Litigation, Hart Publishing, 2004, p. 66.
In February 2012, 21 plaintiffs filed a class action law suit in a US District Court in California against the Regents of the University of California alleging campus police violated their first, fourth, and fourteenth amendment rights (freedom of speech & assembly, unreasonable search & seizure, and taking property without due process of law) as well as provisions set out under California penal, civil, and government codes of false imprisonment/arrest, and failure to provide medical care (after pepper spray was used against them). The case, Baker v. Katehi, was settled out of court in January 2013 after the University agreed to pay damages and allow the American Civil Liberties Union, over a two-year period, to contribute to the University’s rules on the use of force, handling of student demonstrations and crowd control policies.US District Court for the Eastern District of California, Baker v. Katehi, Case No. 2:12-cv-00450; see the report on the University of Michigan Law School’s Civil Rights Litigation Clearing House website.
In the British case of Johnston v. Chief Constable of Merseyside Police, the claimant was given permission to commence civil proceedings for damages arising from an alleged assault (including use of CS spray) and false imprisonment during an incident in Bootle, Merseyside, in 2009. Results of the subsequent case found the defendant’s use of CS spray an unreasonable level of force and resulted in damages being paid to Mr Johnston.Johnston v. Chief Constable of Merseyside Police,  EWHC 2969 (QB), Case No. 9LV21806; and M. Johnson, Bootle Schizophrenic Sprayed with CS Gas Wins Compensation from Police, Southport Visitor, 20 September 2010.
In July 2006, the American Civil Liberties Union (ACLU) of Colorado filed a
sweeping class action lawsuit in federal court … on behalf of prisoners in the Garfield County Jail who … [were] … subjected to widespread excessive force by deputies’ misuse and abuse of PepperBall guns, restraint chairs, Tasers, pepper spray, and electroshock belts.
This case was settled in April 2011 after changes to the jail’s operating rules, internal reporting systems, and increased access to due process (among other actions).ACLU, ‘ACLU of Colorado Challenges Abuse of Prisoners at Garfield County Jail’, 19 July 2006.
In the 2002 case of Headwaters Forest Defense v. County of Humboldt, the US Court of Appeal for the Ninth Circuit concluded that the use of RCAs against peaceful protesters as an excessive use of force.US Court of Appeal for the Ninth Circuit, Headwaters Forest Defense v. County of Humboldt 276 F.3d 1125, 1 November 2002.
Last updated on: 20 July 2017
Chemical irritant compounds have been used widely throughout history. They were allegedly used against the Ambracians by Marcus Fulvius in the 2nd Century BC and by the Byzantines to harass their enemies. Further, Plutarch, a Roman historian, describes the use of ‘an irritant cloud’ by a Roman general to drive an enemy from a cave in Spain.J. P. Robinson, The Problem of Chemical & Biological Warfare, Vol. 1 in The Rise of CB Weapons, Humanities Press, 1971 in F. R. Sidell, ‘Chapter 12: Riot Control Agents’, in The Textbook of Military Medicine: Medical Aspects of Chemical & Biological Warfare, 1997.
The development of the chemicals used in today’s RCAs (CN, CR, CS, OC, and PAVA) began in the late 1800s with the synthesis of CN by German chemist Carl Graebe.H. Salem et al., ‘Chapter 13: Riot Control Agents’, in M. Lenhart (ed.), Textbooks of Military Medicine: Medical Aspects of Chemical Warfare, US, 2008. According to Salem et al. (2008), CN was the RCA of choice from the latter part of the 1914–18 War until the 1950s when it was replaced with CS. Despite this replacement, CN is still in use today and is sold by a number of companies worldwide in the form of self-defence sprays and tear gas grenades/canisters. A total of 67 states parties to the CWC declared holdings of CN in 2011.Report of the OPCW on the Implementation of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction in 2011. CN has been recently used in:
Yemen (2011) – images show fired US-made CN canisters photographed after protests in the capital Sana’a.L. Loveluck, Yemen & the War on Terror, Varsity Blogs, 13 March 2011. and in the Red Sea city of Hodeidah. Yemen Rights Monitor, Protests March 16, Hodeidah, 16 March 2011.
Mexico (2007) – images show fired US-made CN canisters photographed in Oaxaca in 2007. El Enemigo Comun (2007) Corporate Criminals in Oaxaca, reprinted through IndyMedia, 21 July 2007.
Panama (2001) – images show fired US-made CN canisters photographed in the capital Panama City. E. Jackson, ‘Turmoil in the Capital’, Panama News, May 2001.
CS was first synthesised by British scientists Corson and Stoughton in the 1920s but was not widely accepted for use as an RCA until after 1945 when it was discovered that it was ‘less toxic but more potent than CN’.Salem et al. (2008) (op. cit.). Today, CS is the most widely used RCA, and 111 states parties to the CWC have declared holding CS.Report of the OPCW on the Implementation of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction in 2011. CS has been recently used in many countries, such as:
Azerbaijan (2013) – Israeli-made CS smoke canisters photographed after a demonstration in Baku in March 2013 A. Kazimova (2013) 10 mart aksiyaindaki qulaqbatiran LRAD, Azadliq Radiosu, 13 March 2013.
Bahrain (2012) – images show Brazilian & South African CS gas canisters photographed in Bahrain.
Equatorial Guinea (2012) – French-made CS gas canister photographed being fired by police at Bata Stadium, Bata, January 2012 A. Dalsh (2012) Reuters image ID: GM1E81M1M9701).
Kenya (2012) – French-made CS gas canisters photographed on the belt of a police officer standing guard outside a damaged shop during unrest in Mombasa, August 2012AP Image reprinted by Yahoo News (2012) Riot Police Stand Guard Outside a Damaged Shop in Mombasa, 27 August 2012.
Malaysia (2012) – US-made CS canister photographed after the Bersih 3.0 sit-in rally in Kuala Lumpar, Malaysia, April 2012 PDRM Blog (2012) PDRM 2.0, 30 April 2012.
Peru (2012) – CS gas canisters photographed on the vest of a Peruvian police officer during a protest against a mining project in Cajamarca, Peru on 6 August 2012. The canisters appear visually similar to those made in Spain, and under licence from the Spanish companies in Venezuela E. Benavides (2012) Getty Image ID: 147956867.
Senegal (2012) – French-made CS gas canisters photographed on the vest of a Senegalese police officer during demonstrations in Dakar, 19 February 2012 Seyllou (2012) Getty Image ID: 139311166.
Sudan (2012) – Chinese-made CS gas canister photographed in Sudan during protests in June 2012 Images collated from various sources by Right Now I/O.
Turkey (2013) – images show fired US-, Brazilian-, and South Korean-manufactured CS canisters/grenades after protests in Istanbul, in 2013 Brown Moses (2013) Imgur Collection.
CR, the most recently synthesised but least widely used chemical in use in RCAs today, was developed in the UK in 1962 by Higginbottom and Suchitzsky. It is six times more powerful than CS and 30 times more powerful than CN.Omega Foundation, Crowd Control Technologies: An Appraisal of Technologies for Political Control, 2000. While not widely used today, there have been unconfirmed allegations of use of CR in Egypt (2011) and in Bahrain (2012);P. Beaumont and J. Domokos, ‘Egyptian Military using “More Dangerous” Tear Gas on Tahrir Square Protesters’, The Guardian, 23 November 2011; G. Carlstrom, ‘Bahraini Villagers Fear Effects of Tear Gas’, Aljazeera, 2 April 2012. and it is still currently manufactured in the Czech Republic by the Oritest Group and recently manufactured in India by Tear Smoke Unit, although their CR and CN products had (at time of writing) been removed from their respective websites. Less recently, reports indicate that South Africa manufactured more than 20 tons of CR for use by soldiers policing black townships in the 1980s as, according to Amnesty International, ‘the government realised it was easy for people to deal with the effects of CS gas.’Amnesty International, The Pain Merchants: Security Equipment and its use in Torture and Ill-Treatment, ACT 40/008/2003, 2003. A report from 2005 indicates that CR was secretly authorised by the British government for use in prisons in Northern Ireland in the 1970s in the event of attempted mass breakout, and allegedly used in 1974 to quell rioting at Long Kesh prison, nine miles southwest of Belfast.C. Morrison and M. Bright, ‘Secret Gas was Issued for IRA Prison Riots’, The Observer, 23 January 2005, cited in Salem et al (2008 (op. cit.).
OC was developed in 1960 at the University of Georgia by Jenkins and Hayes. It is derived from the naturally occurring capsicum species of plant and as such, the components of it can vary depending on the crop chosen to manufacture the product.Omega Foundation (2000), op. cit.). OC was originally developed as an animal repellent and sold under the brand name HALT! In the late 1980s, the firearms training unit at the FBI Academy in Virginia, US, undertook a three-year study on OC and subsequently authorized its use by its special agents and SWAT teams to ‘control unruly subjects without having to resort to a physical confrontation or deadly force’.Safety Gear HQ, ‘The History of Pepper Spray’, undated but accessed in October 2013.
PAVA is a capsaicinoid that occurs naturally as a minor component in certain varieties of pepper; it can be synthetically produced. PAVA used in RCAs is predominantly sourced as a synthetic formulation and as such has a consistent strength and composition.Haber et al., Human Effectiveness & Risk Characterisation of OC & PAVA Handheld Devices, Air Force Research Laboratory, May 2007. PAVA is ‘believed to have similar but safer effects … than the natural form of OC’.Salem et al (2008) (op. cit.)
OC and PAVA have become widely used by law enforcement officials for both self-protection and crowd management. Recent examples of their use include:
Bahrain (2012) – images show a Bahraini police officer spraying a woman in the face with a handheld pepper spray during anti-government protests in Manama, 12 October 2012.L. Davidson, ‘Violence Rapidly Escalating in Bahrain’, Washington Post, 12 October 2012.
Brazil (2013) – images show a Brazilian police officer spraying a protester with what appear to be a Brazilian-made handheld pepper spray in Rio de Janeiro.V. Caviano (2013) reprinted on the BBC website, Day in Pictures 18 June 2013.
Israel (2012) – images show Israeli border police officers using handheld pepper sprays whilst detaining a protester in Jerusalem, March/April 2012 A. Awad (2012) reprinted on the BBC website, Week in Pictures: 31 March – 6 April 2012.
Turkey (2013) – images show police using backpack-style sprayers to disperse crowds during protests, and using pepper spray in their water cannons, in Istanbul in May and June 2013 L. Harding (2013) Turkey’s Resistance Image Forged as Pepper Spray Burns Woman in Red Dress, The Guardian, 5 June 2013, and Facebook (2013) Photos of Police Adding JENIX Pepper Spray to the Water from the TOMAs Water Cannons, 15 June 2013.
US (2011) – images and video show University of California campus police officers dousing peaceful sit-in protesters with pepper spray, November 2011 BBC News (2011) Pepper Spray: US Campus Police Suspended, BBC News Online, 20 November 2011.
Last updated on: 20 July 2017
Of the most commonly used RCAs today, CN, CS, CR, and PAVA, are crystalline solids at room temperature, and OC is an oil. They are delivered in relatively low concentrations, in several ways:
As a smoke or powder – many hand-thrown or weapon fired products are available which deliver either a dense cloud of irritant smoke or a direct localised burst of irritant powder. These include:
Grenades which are activated by a fuse and can be hand-thrown or weapon fired via grenade launchers or ‘launching cups’ which fit over the muzzle of conventional shotguns or rifles allowing them to fire larger calibre ammunition. Irritant is dispersed via hot gases and smoke produced through pyrotechnic burning of the payload. Manufactured worldwide in states such as Argentina, Brazil, China, India, the Republic of Korea, and the USA, grenades most commonly contain CS but are also available containing CN, CR and OC. These are designed to be fired at the ground where they release their irritant into the surrounding area.
Cartridges consist of a cartridge case containing either a projectile which is expelled, or the irritant load; like ammunition for conventional arms, they must be fired from a weapon. They range from 12 gauge shotgun rounds up to 40mm cartridges and can be fired from a range of devices including shotguns and a wide variety of specially designed launchers (often called ‘riot guns’). The projectiles have a range of up to 100 metres and once fired a pyrotechnic charge initiates burning to expel the irritant, or a blast charge initiates to disperse powdered irritant. ‘Muzzle blast’ cartridges expel powdered irritant directly from the muzzle of the weapon and are designed for close in fire up to approximately 10 metres. Some cartridges are designed to be fired at the ground where they release their irritant into the surrounding area; however, ‘direct impact projectiles’ are also available which are designed to be fired directly at an individual, which on impact release a small localised burst of powdered irritant combining kinetic impact with irritant effect. Cartridges most commonly contain CS but are also available containing CN, CR, and OC.
‘Pepperball’ and other specially designed projectiles, typically containing OC or PAVA, are designed to be fired directly at an individual using a high pressure air gun. Some projectiles, such as the US-made ‘Pepperball’ projectiles are similar in design to paintball projectiles used for recreational purposes (i.e. a small gel ball containing powdered irritant which splits open on impact releasing a small cloud of irritant). The FN303, manufactured in Belgium by FN Herstal and under licence in the US by FNH USA, consists of a fin-stabilized polystyrene projectile with a bismuth forward payload which, like their paintball-style counterparts, split open on impact to release the irritant payload.
‘Wide-area’ RCA delivery mechanisms including multiple munition launchers, mortar munitions, artillery projectiles, heliborne munition dispensers, cluster munitions, unmanned aerial or ground vehicles, among others, are designed to disperse large amounts of RCAs over wide areas and/or extended distances. These products predominantly contain CS, although others containing CN, CR, and OC have also been developed. The development of certain forms of wide-area RCA delivery mechanisms is a cause for concern given the dangers of: (a) employment of inherently inappropriate munitions for law enforcement; (b) proliferation to and misuse by non-state actors; (c) misuse to facilitate human rights violations; (d) potential employment in armed conflict; and (e) their potential use in chemical weapons programmes. Certain forms of ‘wide-area’ RCA delivery mechanisms may have utility in large scale law enforcement situations provided they meet the CWC ‘types and quantities’ provision and are employed in conformity with human rights standards. Other forms of ‘wide-area’ RCA means of delivery appear to be completely inappropriate for law enforcement. Such means of delivery could inherently breach the CWC ‘types and quantities’ provision and/or the prohibition on the use of RCAs as a ‘method of warfare’.For further discussion see: M. Crowley, Drawing the Line: Regulation of ‘Wide Area’ Riot Control Agents under the Chemical Weapons Convention, Report, 2013. Products of concern have been manufactured in a range of countries since the coming into force of the CWC in 1997, including China, India, the Russian Federation, Serbia, Turkey, and the USA.
As a liquid spray or foam, having been dissolved in a suitable solvent, the irritant is then sprayed or expelled from a range of devices. These include:
Handheld Sprays (aerosols) which usually contain OC or PAVA but are also available in CS, CN, CR, or a mixture thereof. Typically ranging in capacity from 25 millilitres up to one litre. They are manufactured worldwide and are widely used for law enforcement purposes, but also by civilians as personal protection sprays.
Larger ‘over the shoulder’ or ‘backpack-style’ sprayers disperse larger amounts of irritant with a capacity of up to several litres. They commonly contain OC or CS, or an OC-CS mixture. These larger sprayers have been used for law enforcement purposes in States such as Australia, DR Congo, Greece, Mexico, Peru, Turkey, Uganda, and the USA, and are manufactured in China, Germany, Israel, Poland, and the US, among others.
Confined-area extraction devices are predominantly manufactured in the USA and consist of a handheld spray with a ‘wand’ attachment for dispersal of OC spray into a confined area such as a cell, closet, or vehicle, etc.
Water cannon – most models of water cannon are manufactured with two or three separate tanks; the largest for the water and then one or two smaller additional tanks which can contain RCAs (predominantly CS or OC) and/or dye marking products which are mixed with the water for dispersal. As most of the RCAs are unstable and insoluble in water, the irritant is injected into the water stream at the last moment. Water cannon with tanks for RCA dispersal are manufactured in states such as China, Israel, the Republic of Korea, the Russian Federation, and the USA, among others.
As a vapour fog or irritant cloud, having been mixed with a solvent to produce a dense fog or cloud, they are usually dispersed via:
Fixed delivery systems – which are usually installed in secure rooms or places of detention, they disperse CS or OC into an enclosed space via remote control. They are manufactured in Germany and the USA, among others.
Aerosol grenades are a newer type of delivery mechanism for OC, CS or an OC/CS mix. They are a small aerosol with a single activation that empties the entire contents in one burst. They have been advertised as being suitable for use in confined spaces in order to force an individual or group to leave the space, as an area denial system (i.e. to deny access to an enclosed space), and for crowd control purposes. They are predominantly manufactured in the USA.
Hand-held ‘foggers’ – which have been promoted for use during crowd control or law enforcement situations. Mostly manufactured in the USA, hand-held ‘foggers’ can disperse OC, CS, or CN.
Last updated on: 20 July 2017
RCAs are intended to cause temporary incapacitation through sensory irritation; the effects of which disappear within a short time following termination of exposure.
CS, CN, and CR all have similar effects causing a ‘burning sensation in the eyes … severe irritation of the respiratory tract, burning pain in the nose, sneezing, soreness and tightness of chest. Even very light exposure can cause a rapid rise in blood pressure, and as this increases, gagging, nausea and vomiting occur’.H. Hu et al. (1989) 'Tear Gas: Harassing Agent or Toxic Chemical?', Journal of the American Medical Association, 1989, 262:660-3, in Amnesty International (2003) (op. cit.).
OC and PAVA (like CS, CN and CR) ‘interact with sensory nerve receptors in skin or mucosae to produce local sensation (discomfort, itching, burning sensation, or pain) … The principle effects of these agents are on the eye, respiratory tract, and skin ... on the eyes, depending on the concentration, the effects are local itching, discomfort, or pain with excessive lacrimation [tearing] and blepharospasm [involuntary tight closure of the eyes]’.H. Salem et al. (2008) (op. cit.).
Conditions affecting an individual’s reaction to the effects of RCAs include, ‘excessive application of the agent, delivery in an enclosed space, prolonged exposure (as when the victim cannot flee), a high minute ventilation (as during a fight), and (for skin reactions) high temperature and relative humidity’.A. R. Hill et al. (2000) Medical Hazards of the Tear Gas CS: A Case of Persistent, Multisystem, Hypersensitivity Reaction and Review of the Literature, Medicine 79:234-40, 2000.
Unintended effects of the use of these types of RCAs include contact dermatitis, skin blistering, pressure injury to the eyes, bronchoconstriction, and death.Haber et al (2007) (op. cit.), Levin, R et al (1973) Contact Sensitization to CS, A Riot Control Agent, Edgewood Arsenal, Aberdeen Proving Ground, Maryland, November 1973, and Salem, H et al (2008) (op. cit.).
The solvents used to dissolve the chemical irritants can also be harmful. Studies of OC sprays found that some contained toxic solvents: one individual who was exposed to a training spray that contained the substance trichloroethylene, but no OC, went on to develop corneal erosions, with alteration of vision that lasted two days, while use of a Russian-manufactured pepper spray containing unidentified solvents caused ‘severe chemical burns’ and eye damage lasting more than six weeks.M. Holopainen et al. (2003) Toxic Carriers in Pepper Sprays may Cause Corneal Erosion, Toxicology and Applied Pharmacology 186 (2003) 155–162). Concerns have also been expressed about the carcinogenic potential of the solvent MIBK, used to deliver CS (Rappert, B (2003) Health and Safety in Policing: Lessons from the Regulation of CS Sprays in the UK, Social Science & Medicine, 56 (2003) 1273.
Further unintended effects which are not related to the chemical content of riot control munitions per se include impact injuries causing penetrating trauma, which can be exacerbated by the presence of the chemicals in use. It has been documented that a number of individuals have been struck at close range or in sensitive areas of the body with weapon-fired RCAs such as grenades, cartridges, and other specially designed projectiles causing blindness, other serious injury or death.See, e.g., Hu, H et al (1989) (op. cit.), Ijames, S (2007) Tragedy in Boston: The Impact Projectile Death of Victoria Snelgrove, PoliceOne, December 1st, 2007, Law, B (2013) Bahraini Dies after Being Stuck by Tear Gas Canister, BBC News Online, February 22nd 2013, Sollom, R et al (2012) Weaponizing Tear Gas: Bahrain’s Unprecedented Use of Toxic Chemical Agents against Civilians, Physicians for Human Rights.
While some studies have found no long-term physical effects resulting from single or controlled exposures to CS gas or OC,See, e.g., Karagama, YG (2003) Short Term & Long Term Physical Effects of Exposure to CS Spray, Journal of the Royal Society of Medicine, 2003, Vol. 96(4), and M. Vesaluoma et al. (2000) Effects of Oleoresin Capsicum Pepper Spray on Human Corneal Morphology and Sensitivity, Investigative Ophthalmology and Visual Science, 2000 41(8). longer term effects of exposure to high concentrations of RCAs and/or multiple and repeated exposures over a long period of time is less clear and more concerning.
Research from the Occupied Palestinian Territories in the 1980s, the Republic of Korea in 1987, and Bahrain in 2011–12, indicate that exposure to high concentrations of RCAs and/or exposure over a long period of time can potentially be linked to increases in miscarriage, still-births, and other reproductive anomalies; an apparent rise in asthma rates, respiratory failure, and deterioration in lung function; and that they have the potential to cause long-term carcinogenic effects.L. F. Chasseaud et al. (1975) Suppression of Sebaceous Gland Non-Specific Esterase Activity by Electrophilicaβ-Unsaturated Compounds in Sollom, R et al (2012) (op. cit.), Hu, H et al (1989) (op. cit.), Physicians for Human Rights (unknown); The Casualties of Conflict in Sollom, R et al (2012) (op. cit.), Sollom, R et al (2012) (op. cit.).
There are a number of concerns surrounding specific uses of RCAs.
In recent years, photographic evidence indicates that expired RCAs have been used in Bahrain (2012), Egypt (2011), India (2012), the Occupied Palestinian Territories (2011), Turkey (2013) and Venezuela (2009).Brown Moses (2013) Imgur Collection, Elsadeq, K (2011) via Twitter, Omega Research Foundation Archives (2009), Proud to be an Indian (2012) via Facebook, STR/Getty (2012) Getty Image ID: 143178781, Wadi Hilweh Information Center (2011) Israel using Expired Tear Gas on Palestinians of East Jerusalem (with pictures).
Generally, RCAs have a shelf life of three to five years, after which they should not be used. The US company Federal Laboratories, in its pamphlet entitled ‘Riot Control’, stresses that inappropriate storage of their RCAs and/or use after the recommended five year shelf life can cause the equipment to malfunction. It states that while out-of-date material should not be used for riot control, they can be used as training aids as ‘in practice sessions it is of no great importance if a device should malfunction’.Federal Laboratories (date unknown) Riot Control, Federal Laboratories. However, little research has been conducted into how the potency of the irritant is affected over time which leads to further concerns (such as on the health of those exposed to the chemical) in addition to the risk of the device malfunctioning.
The use of RCAs in confined spaces with limited ventilation is inherently risky and can lead to injury or death through suffocation, allergic reaction or hazardous overdose. RCAs should never be used in confined spaces, or in a place where there is no opportunity for the target to easily escape the effects of the RCA such as in a stadium or a narrow street or alleyway.
Some RCA dispersal systems available on the market today appear to be, by their very nature, indiscriminate. Water cannons with separate RCA tanks, hand-thrown or weapon-fired grenades and cartridges, and larger sprayer systems, are not targetable to any one individual and as such can affect innocent bystanders. Use of small targetable sprays helps to minimize the risk of excessive amounts being used and of bystanders being affected.
RCAs should never be used on an already-restrained individual and never in conjunction with spit hoods or masks as this increases the risk of death or serious injury through allergic reaction, suffocation or positional asphyxia, among others.Spit hoods/masks are placed over the head and mouth of an individual and are designed to prevent the wearing spitting. If used in conjunction with chemical irritants they increase the risk of suffocation by prolonging the closeness of the chemical to the nose and mouth and thus preventing the wearer escaping the effects.
Some RCAs contain flammable propellants and should therefore not be used alongside electric shock weapons (such as Tasers) or where there is a fire risk.
Research indicates that some population groups are more likely to be affected by RCAs, for example, those with underlying heath issues such as asthma or hypertension and those who take cocaine;Department of Health (1999) 1999 Annual Report of the Committees on Toxicity Mutagenicity Carcinogenicity of Chemicals in Food, Consumer Products and the Environment, and J. Mendelson et al. (2010) Capsaicin, an Active Ingredient in Pepper Sprays, Increases Lethality of Cocaine, Forensic Toxicology, January 2010, Vol. 28 (1), pp. 33-7. further, ‘the use of [CS] spray in the context of alcohol, drugs and mental illness remains unchartered territory, where the risk is not fully known’ and as such should be used with caution.The Police Complaints Authority (2000) CS Spray: Increasing Public Safety? A Report by the Police Complaints Authority.
Last updated on: 20 July 2017