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The global wave of protests against racial injustice and police violence, sparked by the heartbreaking death of George Floyd at the hands of a Minneapolis police officer, has spread across major U.S. cities and beyond. In many instances, protesters have faced intense resistance from law enforcement armed with tear gas, a chemical weapon dating back to the early 20th century.
What exactly is tear gas?
Tear gas is not a single substance, and despite the name, it is typically not in gaseous form. Various compounds serve as 'lachrymatory agents,' most of which are solid at room temperature. These compounds are often mixed with other dispersal agents, such as liquids or gases, for deployment.
What is the origin of tear gas?
Tear gas has been experimented with by military forces since World War I. Both France and Germany developed and used lachrymatory agents in combat, although there were some initial challenges. As noted by the U.S. Army's Combat Studies Institute, the Germans launched around 3,000 tear gas shells during a single day of battle in 1914, but the British soldiers who were targeted 'experienced no significant effects and didn’t realize they were under chemical attack.'
Soon after, the Germans refined their methods and began using tear gas effectively. In 1916, they launched 2,000 shells into a French trench system, causing 2,400 French soldiers to become blinded, coughing, and weeping—ultimately trapping them as they were surrounded by German forces wearing protective goggles.
The introduction of CS gas came several decades later. Its key compound, 2-chlorobenzylidene malononitrile, was synthesized by American chemists Ben Corson and Roger Stoughton in 1928. The name 'CS' is derived from the chemists' initials. This variant of tear gas was developed and tested during the 1950s and 1960s.
How does tear gas affect individuals?
Tear gas irritates the mucous membranes in the eyes, nose, mouth, and lungs, leading to tearing, coughing, burning, and stinging sensations, along with chest tightness and difficulty breathing. At higher concentrations, exposure may result in stomach irritation, causing vomiting and diarrhea.
German toxicologist Uwe Heinrich explains that dispersing tear gas at a concentration of 1 mg per cubic meter leads to symptoms of irritation. As the concentration increases, the effects worsen rapidly. A concentration of 10 mg per cubic meter can force even well-trained soldiers to withdraw from the area. Concentrations between 10 and 20 mg/m3, or higher, can lead to severe injury or, depending on the individual and exposure conditions, death. In one case reported in a Swiss medical journal, a healthy adult man exposed to a tear gas grenade containing just one gram of CS while inside a building developed toxic pulmonary edema, a condition where excess fluid collects in the lungs, causing difficulty breathing. He only recovered after weeks of medical treatment.
Exposure to tear gas may increase susceptibility to respiratory illnesses such as influenza or COVID-19, according to Duke University anesthesiology professor Sven-Eric Jordt, as he tells OneZero. Prolonged exposure in confined spaces can lead to long-term damage, including glaucoma, blindness, respiratory failure, and even death.
Since tear gas is actually a solid, its particles can land on surfaces such as clothing, food, animals, and plants. The environmental damage caused by tear gas has not been thoroughly studied, but it likely contributes to air pollution. Additionally, it may disproportionately affect Black and Latino communities already burdened by environmental pollution.
Shouldn’t tear gas be banned?
In a way, yes. Tear gases were commonly used in warfare throughout much of the 20th century until 1993, when the Chemical Weapons Convention outlawed the production, stockpiling, and use of chemical weapons in combat. However, this international treaty does not apply to domestic law enforcement, meaning that police forces in the United States are permitted to use tear gas on civilians, often as a tool for crowd control.
How do you treat exposure to tear gas?
If you're outdoors, the best remedy for breathing issues is fresh, uncontaminated air and some time to recover. In cases of high exposure or if you're in an enclosed space, bottled oxygen or specific asthma medications may be administered to help ease breathing difficulties. Any affected skin should be cleaned with soap and water, and eyes should be rinsed with sterile water or a saline solution. Some protesters use a mixture of baking soda and water based on the belief that the basic sodium bicarbonate can weaken the tear gas molecules and lessen its effects. Others have tried using milk or milk of magnesia to soothe the burning from pepper spray, though experts warn that these substances aren't sterile and could lead to infections.
This story has been updated for 2020.
