Tear gas traces its roots back to Middlebury

The discovery of the tear gas component 2-chlorobenzylidene malononitrile (CS gas) by two Middlebury chemists propelled modern riot control industry

By Lucy Townend

While Middlebury chemists Ben Corson and Roger Stoughton discovered CS gas in Warner Hall in 1928, the compounds used in modern-day tear gas have not changed much since it started to be used in the riot control industry in the 1950s. (Henry Sheldon Museum)

In 1928, Ben Corson and Roger Stoughton were investigating the reaction between carbonyl compounds and malononitrile in Warner Hall at Middlebury College when they discovered 2-chlorobenzylidene malononitrile (CS). Even though it garnered little attention when published in the Journal of American Chemistry Society, CS gas is now one of the most widely-used components in tear gas, a riot control agent that has been used in recent weeks on protesters against police brutality and systemic racism. 

It also recently dominated the headlines after President Trump used it to clear protesters in Lafayette Square. 

According to Dr. Simon Cotton, a chemistry professor at the University of Birmingham, most tear gases are not technically gases; they are made up of tiny, solid particles of substances like CS that are released in a spray or fog. These tiny particles act as an irritating agent, sending warning messages to the brain that primarily affect our respiratory systems and mucous membranes and causing burning sensations, tears and nausea. Tear gas will also adhere to any nearby surfaces, including the ground or buildings. 

“Tear gases are designed to attack the senses simultaneously, intentionally producing both physical and psychological trauma,” said Dr. Anna Feigenbaum, a professor at Bournemouth University, in an email to The Campus. Part of Feigenbaum’s research focuses on how tear gas transitioned from being used by the military in World War I to being used as a riot control agent by law enforcement. 

“Protest often involves a contest between activists and the state,” said Jim Ralph, professor of history at Middlebury. In an email to The Campus, Ralph described a confrontation that took place in Boston in March 1770, when the British fired at and killed five protestors who were upset at the military occupation of their city. 

“As this example suggests,” said Ralph, “governments have often turned to the display (and the use) of force to seek to control crowds.” 

While chemical weapons were first used by the French during World War I, CS gas was not used until the 1950s, almost thirty years after Corson and Stoughton discovered the compound. The British began investigating the properties and effects of the chemical at Porton Down, one of the oldest chemical warfare investigation sites in the world with a history of accusations of unethical human testing

“I had a searing hot pain in my chest for two minutes,” reported one man who was exposed to CS at the research facility for five minutes. “My eyes watered a great deal, despite the goggles, and I was salivating markedly.” The British then shared their findings with the United States. 

This sharing coincided with the rise of riot control forces that were distinct from other law enforcement in the 1900s. “The underlying theory of police response to crowd control into the 20th century was that the crowds quickly turned into mobs,” Ralph said. In 1968, this modus operandi was demonstrated as protestors at the Democratic National Convention were fired at by police officers, even as some police departments were beginning to develop tactics to prevent police from escalating conflicts. 

“After civil unrest — and its repression — in the 1950s and 1960s, riot control became an industry of its own,” Feigenbaum said, describing the ways in which CS and other tear gases began to be marketed as a safe and humanitarian method of dispelling and defending against crowds in the United States. 

“The idea has always been that using these chemicals for crowd control might actually be a more progressive way to use them,” Dr. Stuart Schrader said in an interview with The Campus. Schrader studies policing, counterinsurgency and racism at Johns Hopkins University. When asked whether police should use tear gas on protesters, Schrader said that police should not. 

“At the same time, I do think it’s important to recognize that if the alternative is police firing guns into crowds, then CS is perhaps better,” Schrader said. 

Part of the argument for the use of tear gas involves using it as a defensive tactic as opposed to an offensive tactic. According to Schrader, this rationale was used by the Johnson administration to justify the use of CS gas in Vietnam beginning in 1968, as they claimed that it was used in crowd control or to de-escalate situations. 

“That was a misleading argument,” Schrader said. “Just as today, in what we’ve been seeing over the past couple of weeks, these chemicals are not being used in a de-escalatory or defensive fashion.” As the military realized the capabilities of CS gas in Vietnam in the late 1960, domestic law enforcement began using CS gas in similar ways against civilians. 

In 1997, tear gas was banned from use in warfare by the Chemical Weapons Convention. However, there is a provision that allows tear gas to be used in riot control by domestic law enforcement, which has allowed for its legal use in the United States. When asked about the chances of a nationwide ban on the use of tear gas in the United States, Schrader was not optimistic. 

“A national ban might be a pretty high hurdle,” Schrader said, citing the difficulty of passing any legislation through Congress, “but I do think it might be possible at a municipal level.” According to the Los Angeles Times, some lawmakers in Congress plan on introducing a bill to ban tear gas, while some cities, such as Dallas, have begun to ban tear gas. 

When discussing the legality of tear gas, the terms “lethal” and “less lethality” tend to spark significant debates. 

“CS is supposed to incapacitate, and it is supposed to be non-lethal,” Cotton said. “It is supposed to be lethal if you use it in confined spaces.” In recent protests, police have appeared to spray a gas to trap protesters in confined spaces, such as when a protest in Philadelphia moved to a highway on June 1. 

Feigenbaum discussed the effectiveness of the term “less lethality” as a way to describe the relative violence associated with a weapon.

 “If I shoot you in the foot, you are less likely to die than if I shoot you in the head,” said Feigenbaum. “However, this does not mean that the foot bullet is a ‘humanitarian agent’ whereas the head bullet is a violent weapon.”

In Cotton’s opinion, Corson and Stoughton should not be faulted for creating a harmful chemical compound. 

“Chemistry is neutral in the sense that a molecule is not good or bad,” said Cotton. “Whether chemicals are good or bad depends on what they are used for.” He noted that the two chemists presented their findings publicly in the Journal of American Chemistry Society. 

“Think about this,” said Cotton. “If they had found it with the intention of using it as a weapon of war, would they have reported it publicly? Of course they wouldn’t.” 

Schrader, however, has a more nuanced perspective of the responsibility of chemists creating compounds that can be used for nefarious purposes, claiming that scientists do need to acknowledge the consequences of their discoveries. 

“If it’s a profoundly unjust, racist world, then these technologies might be used to bolster or strengthen those inequalities,” Schrader said. However, Schrader also acknowledged the 30 year gap between the discovery of CS gas in Warner Hall and its use for crowd control. 

“I don’t necessarily think that the responsibility rests on Middlebury’s shoulders, because there also needed to be policymakers who took this chemical and used it in the way that it was used.”