Pass the mustard: riot-control agents and mistaken identity

Dan Kaszeta is a chemical weapons expert who has written a great deal about the Kremlin’s disinformation campaign around its Skripal assassination attempt and other subjects. Here he explains why tear gas and other riot-control substances are not chemical weapons.

As I have written on this forum before, chemical warfare agents and chemical weapons are not well understood by the general public. Indeed, even among journalists working in defence or security affairs, some general concepts are not well understood. This has given rise to both formal reporting and social media posts that are not entirely based in fact.

Riot Control Agents

A noticeable trend that has emerged in the last few years has been the accidental or deliberate misidentification of riot control agents. These substances, often referred to by euphemisms such as “tear gas” or “pepper spray”, have been around for over a century. While their use in warfare is no longer permitted under the terms of the Chemical Weapons Convention, the same treaty specifically permits their use for domestic law enforcement operations.

The most commonly encountered riot control agents are the substance CS, often deployed from burning or bursting grenades, as well as in spray form, or various oleoresin capsicum (OC) sprays — known colloquially as pepper sprays as they are derived from hot peppers. Also, smoke grenades and smoke flares, generally designed for screening and signaling, have occasionally been used by security forces and mistaken for other things. Reports about Venezuela, Turkey, Indonesia, the United States, France and the UK have misrepresented riot control agents and smokes as other things.

A common theme seems to be to refer to riot control agents as “mustard gas”. So-called “mustard gas” is the chemical compound sulfur mustard, which has no utility in riot control. It is actually an oily liquid, not a gas, and it’s effects are only felt hours after exposure, so it has no usefulness in dispersing a crowd. Needless to say, no reports have ever emerged from any medical treatment facility of anyone with clinical signs indicative of mustard use in conjunction with any of these alleged incidents.

Venezuela

Venezuela has seen civil unrest for years now, and the security forces have shown little compunction in using riot control agents. In 2014, various social media posts reported the use of “mustard gas”, which turned out to be tear gases. One example of several is here. Some reports mistook yellow smoke for mustard, out of the mistaken belief that the name derives from its colour. The name actually derives from the smell of it in liquid form, variously described as being like mustard or burnt garlic. The smell of heated mustard seed oil is actually quite close to the smell of sulfur mustard. Tweets in 2017 (example here) repeated claims of mustard use.

Some other reports in 2014, largely Twitter posts, referred to “green poison gas”. Reports were further confused by the possible use of the old chemical agent Adamsite. This is a vomiting agent, and although it is largely not used for riot control purposes, it was commonplace in the 1960s in military tear gas grenades and has a very long shelf life. However, its use in domestic law enforcement, while rare, appears to fit into the exceptions written into arms control law.

Turkey

In 2013, a National Geographic article erroneously described tear gas as a nerve agent, in the context of reports of tear gas. This article quoted a US academic, not known as a specialist in nerve agents, explaining that tear gases like CS stimulate pain responses in nerve endings. However, that is not the actual definition of a nerve agent. Nerve agents are complex chemicals that bind with the enzyme acetylcholinesterase in the nervous system, causing a variety of signs and symptoms by binding with this chemical. That is not the same thing as stimulating a pain response. It is akin to confusing a stick with a gun. Indeed, if I were to hit someone in the head with a stick, that would cause pain responses in the nerves. This does not mean that a stick is a nerve agent.

Another situation in Turkey saw the absurd reporting of orange-coloured smoke as “Agent Orange” based largely on its appearance. Photos of the actual ordnance used showed orange-coloured smoke flares. See this link for example. For the record, “Agent Orange” is a nickname for a defoliant, and has no reference whatsoever to the colour of the material.

Indonesia

The West Papua region of Indonesia has had a separatist movement for decades. There have been accusations of chemical warfare by the Indonesian authorities. A recent example is here. The military munitions depicted are clearly 40mm conventional grenade launcher rounds. The spent cartridge even says “HE” for high explosive on it. There’s a definite argument to be made that, maybe, use of 40mm HE grenade launcher rounds is inappropriate. However, they are not chemical weapons. Some of the allegations involve use of white phosphorous. However, in both arms control law and by scientific definitions, white phosphorous is an incendiary weapon, not a chemical weapon. Its use as a weapon is problematic, but not an act of chemical warfare. In addition, Indonesia is not a signatory of the relevant arms control agreement with regards to white phosphorous.

United States

The use of riot control agents is prevalent in the US. Most police carry them and they are widely available for self-defence purposes. A number of instances of police use of riot control agents have attracted exaggerated claims. Protests at Standing Rock, North Dakota, in 2016, attracted claims of mustard gas use by police. The North Dakota state government issued a strong denial of this and many other allegations regarding the Standing Rock protests.

Rioting in Ferguson, Missouri, in response to police activity prompted multiple reports of “mustard gas” use, all of which were hyperbole based on the use of CS. The CNN journalist Don Lemon was alleged to have been hit by “mustard gas” while covering the riots, although he appears not to have made the claim himself. Tweets, now deleted, claimed “mustard gas” use. Another series of now deleted tweets linked to a known Russian troll Twitter account claimed that police in Phoenix, Arizona, were using “mustard gas” in 2017. Use of riot control agents at the US-Mexico border in 2018 led to claims of nerve agent use, based largely on the erroneous National Geographic article mentioned above.

France

Police in France use tear gas on occasion. In June 2016, the former Aston Villa football star Stan Collymore claimed he was sprayed with “mustard gas” when, in fact, he was exposed to a normal riot control agent. The claims went viral at the time, although much of it was due to ridicule of Mr Collymore rather than taking the allegation seriously. In 2018, the use of irritating riot control substances against “Yellow Vest” protesters was alleged to be nerve agent, although no evidence surfaced of this.

UK

Two of the more absurd allegations of mustard gas incidents have been in the UK, neither of which involved police activity. The west London gin distillery Sipsmith had an accident involving an experiment with mustard seeds at some point in 2011 or 2012. In a stunning case of odd journalism, various tabloids years later, in 2016, reported that the distillery had been evacuated due to “mustard gas” being created. For the record, mustard gas has nothing to do with mustard seeds, and the distillery issued a statement on the matter. In 2017, a mysterious cloud of gas or vapour passed over the UK’s south coast at Birling Gap. One of the many theories behind this still-unexplained incident was that it might have been “mustard gas” — possibly leaking from a sunken ship in the channel. However, this is inconsistent with both the reported odour (nobody reported the telltale garlic smell as far as I can tell) and the fact that sulfur mustard is an oily liquid which could, theoretically, have formed a slick on the sea, but not a cloud of gas.

Why does it matter?

Conflating legal substances that are generally, mostly, non-lethal with ones that are not legal and likely to cause lasting illness, serious injury, and or death is not a good situation. If inflated claims are believed, then one side in a party could believe that lethal force is being used. It could be the equivalent of saying “they are shooting us” when in fact the police are using batons, not guns. It could cause escalations in violence if one side thinks the other has committed atrocities.

On a more sinister level, conflating police use of riot control agents, even if disproportionate and cruel, with things like Sarin serves to make false equivalencies. You can see the “well, both Assad and Trump use chemical weapons, so….” arguments around social media. If it leads to a “it doesn’t matter; everyone uses them” attitude, then chemical arms control is undermined.

None of my comments here should be construed as advocacy of use of tear gases and irritating riot control agents in any particular situation. They are largely non-lethal but are certainly dangerous in some circumstances, and their toxicity against vulnerable people, such as children or those with respiratory conditions, is not as well studied as for healthy adults. Riot control agents have a place within legitimate law-enforcement operations, and the scope and rules for that are certainly an area for robust discussion. However, the nature of argument these days seems to be that you say “X is not a chemical weapon”, then the discourse generally degrades to “oh my God you are on the side of the genocidal oppressors of people X” within hours, if not minutes. In reality, one can hold the opinion that People X do not need or deserve oppression AND say that the spent grenade launcher cartridge in the picture is not, in fact a chemical weapon.

The views expressed here may not necessarily represent those of the Integrity Initiative.