Conclusion: Tear Gas, Pepper Spray, and Chemical Weapons


According to reputable official the Honorable Mr. Andrew C. Weber, the Assistant Secretary of Nuclear, Chemical, and Biological Defense programs, “the Office of the Assistant Secretary of Defense for Nuclear, Chemical and Biological Defense Programs has a wide range of duties related to countering Weapons of Mass Destruction (WMD) threats.  Their team of top scientists helps us understand these threats and engage in activities and programs to counter them.  Their duties include overseeing Department of Defense science and technology investments in countermeasures that will enable the United States forces to prevent, protect against, and respond to WMD threats”. However there is still one chemical weapon that is marketed to the masses today and even used against protests: tear Gas.

Tear gas in use

Tear gas was first introduced World War I by the French. It was not very concentrated, and the Germans hardly noticed it was being used. In August 1914, the French fired 26 mm grenades containing ethyl bromoacetate, but the low concentration, only approximately 19cm³ per grenade, was not enough to bother the Germans. Afterwards, due to shortages of bromine, the primary chemical was switched to chloroacetone. The Germans then retaliated with a tear gas of their own making, using it for the first time in October of 1914 on the British. Again, the weapon was so dilute that the enemy combatants did not even notice.

Peaceful protesters in Tahrir Square attempt to flee from the noxious tear gas

Since its debut in the Great War, tear gas, and its famous derivative pepper spray, has transformed from an ineffective weapon of war to a highly efficient tool for dispersing protesters. It has become a lynchpin in the arsenal of modern authoritarian regimes and has seen widespread use in recent years, with the Arab Spring and the Turkish protests being the more high-profile international cases. In an especially ironic incident, tear gas manufactured in the US, the great champion of democracy, was used on protesters in Tahrir Square attempting to enact some democratic reform. In Turkey, when Prime Minister Erdogan tried to seize historic sites and develop them for his cronies, protesters invaded Taksim Square; they were tear gassed. Luckily for them, the tear gas brought international attention to their plight, but that cannot be said of all tear gas victims.

A doctored photograph which emphasizes the inhumane actions of Lt. Pike, who had pepper sprayed a peaceful protester.

Another event exemplifying the political, rather than physical, power tear gas can have was the UC Davis Occupy protest that involved Lt. Pike, a police officer who had pepper sprayed a peaceful protester for no apparent reason. The ensuing media firestorm brought new attention to the waning Occupy Movement, showing that chemical weapons aren’t always so bad. Also, the image of the cop pepper spraying the protesters birthed many amusing pictures, another positive effect of chemical weapons.

3-D Model of 2-Chlorobenzalmalononitrile (CS)

Although tear gas has numerous different forms, 2-Chlorobenzalmalononitrile (also known as CS) is the most common. CS has a chemical formula of C10H5ClN2, composed of several cyanide functional groups, Due to the hydroscopic nature of aerogels, a type of colloid, when silica aerogel is combined with CS, the fluidity, water resistance, chance of exposure and intensity of the symptoms increase.  CS gas is synthesized by the reaction of 2-chlorobenzaldehyde and malononitrile through Knoevenagel condensation. This reaction is composed of two steps: first, the nucleophilic addition of an active hydrogen compound to a carbonyl group and second, a dehydration reaction in which a molecule of water is removed. of the symptoms increase


ClC6H4CHO + H2C(CN)2 → ClC6H4CHC(CN)2 + H2O

There are a couple major components in tear gas. Charcoal is used as an ignitor when combined with potassium nitrate allowing the can to combust. This is because potassium nitrate gives off great quantities of oxygen when it burns, feeding the fire, while charcoal will begin to smolder when the pin is pulled. Silicon is also added so that when the exothermic reaction of potassium nitrate occurs causing super hot glass droplet to forms, igniting the other compounds. The sucrose in the can acts as a fuel source for the fire at a relatively low temperature, vaporizing the O-Chlorobenzalmalononitrile, a lachrymator, irritating the eyes or the nose. Potassium chlorate is an oxidizer creating some of the smoke, while magnesium carbonate is used to to keep the solution slightly neutral. This is all dispersed in nitrocellulose, a sticky binding, to create a homogenous mixture.

Although technically banned under the UN Convention on Chemical weapons, tear gas is not nearly as lethal as other compounds such as Ricin or Sarin gas. In fact it has to be 25 grams per cubic meter for it be lethal when only concentrations 4 grams per cubic meter are used to disperse crowds. However it is still worrying to note that chemical weapons are not just abstract concepts, created in sinister labs in shady countries, but actually used today, even here in the US.