Protests against racism and police brutality triggered by the tragic murder of George Floyd by a Minneapolis police officer have occurred in every major American city and in countries around the world. In many places, demonstrators encountered strong resistance from the police who used tear gas – a chemical weapon that dates back to the early 20th century.
What is tear gas?
Tear gas is not a specific chemical and, despite the name, is not usually a gas. There are several different compounds that are used as “tear remedies”. Most of them are solids at room temperature and are mixed with liquid or gaseous dispersants for use.
Where did tear gas come from?
Tear gases are something that the military has played with since the First World War. Both France and Germany developed and used tear irritants in the fight, but there was obviously a certain learning curve. According to the Combat Studies Institute of the US Army, the Germans fired around 3,000 tear gas cartridges in one day in 1
Shortly afterwards, the Germans had gotten better under control and were using tear-causing gases with great effect. In 1916 they fired 2,000 grenades into a French trench system and 2,400 French soldiers – blinded, coughing and crying – were quickly surrounded by German troops in safety glasses.
CS gas would come a few decades later. Its active component, 2-chlorobenzylidene malononitrile, was synthesized in 1928 by the American chemists Ben Corson and Roger Stoughton (the CS stands for Corson and Stoughton). The tear gas used was developed and tested in the 1950s and 1960s.
What does tear gas do?
Tear gases irritate the mucous membranes of the eyes, nose, mouth and lungs and cause cracks, coughing, burning and stinging. Chest tightness and difficulty breathing. At higher concentrations, exposure can cause gastric irritation, which can lead to vomiting and diarrhea.
According to the German toxicologist Uwe Heinrich, dispersing the gas in a concentration of 1 mg per cubic meter leads to irritation symptoms. From there it gets sour pretty quickly. A concentration of 10 mg per cubic meter can force trained soldiers to withdraw from an area. Ten to 20 mg / m3 or more can result in serious injury or death, depending on the victim and exposure conditions. In an incident reported in a Swiss medical journal, an otherwise healthy adult man was exposed in a building to a tear gas grenade that contained only one gram of CS. He quickly developed toxic pulmonary edema, a condition in which excess fluid accumulates in the air sacs of the lungs and causes difficulty in breathing, and only recovered after weeks of medical treatment.
Shouldn’t tear gas be illegal?
It is somehow. Tear gases were used in warfare for most of the 20th century until the Chemical Weapons Convention banned the manufacture, storage, and use of chemical weapons in combat. However, the international treaty does not apply to the national law enforcement agencies of the nations. As a result, US police officers are free to spray it on civilians, typically as a means to disperse the crowd.
How do you treat tear gas exposure?
When you’re outside, the best antidote to breathing problems is fresh, pristine air and time. In the event of high dose exposure or exposure in closed rooms, oxygen in bottles or certain asthma medications can be administered to relieve breathing difficulties. Any exposed skin should be washed with soap and water and the eyes rinsed with sterile water or saline. Some demonstrators use a solution of baking soda and water to theorize that the basic sodium bicarbonate can weaken the molecules in tear gas and counteract its effects. Others have used milk or magnesia milk to combat the burning sensation in pepper spray. Experts warn that these liquids are not sterile and can cause infections.
This story was updated for 2020.