Video footage from the 1970s shows CS gas being tested on Army volunteers sheds light on a practice that continues in the US military today.
Footage shows soldiers entering a gas chamber without any facial protection, where a small amount of the tear gas is released for approximately 30 seconds of exposure.
The soldiers can be seen coughing, rubbing their eyes and retching after they are released from the chamber.
Gas exposure helped military officials at the time see how people would be affected during combat missions, and the testing is still done today as part of a soldier’s training.
US soldiers exposed to CS gas, or tear gas, in 1972 can be seen coughing and rubbing their eyes
The US Army first started testing CS gas on volunteer soldiers in the 1970s, but the practice still continues today
The volunteer soldiers were exposed to the gas for 30 seconds in a chamber before a similar test took place outside
The video, which recently resurfaced, was made by the Department of Defense in 1972.
Later in the video, several soldiers are shown out in the field as a cloud of CS gas is released on their position, with the men being told they are allowed to put on gas masks when they feel it is appropriate.
Several fail to do this in time, though, again resulting in an adverse reaction to the chemical.
But while the video may seem like an outdated practice from a bygone era, the truth is in fact the exact opposite.
New recruits to all branches of the US military still have to take part in CS gas training today, though it is done in a far more controlled environment.
Footage shows soldiers entering a gas chamber without any facial protection, where a small amount of the tear gas is released for approximately 30 seconds of exposure
The video of the soldiers, which recently resurfaced, was made by the Department of Defense in 1972
During initial training, refresher courses and equipment maintenance exercises members of the armed forces are exposed to CS gas tablets melted on a hotplate.
Following exposure to the gas while wearing masks, troops are told to take off their protective gear and endure the exposure.
The training demonstrates the importance of properly fitting protective gas masks.
Developed by two students in 1928 at an American university, CS gas was first tested by the British in the 1950s and 60s before being picked up by the Americans toward the end of the 1960s.
The compound 2-chlorobenzalmalononitrile is the main component of CS gas, and it is used by domestic police forces around the world as a crowd control device, despite its use in warfare being banned by the Chemical Weapons Convention of 1997.
The compound 2-chlorobenzalmalononitrile is the main component of CS gas, and it is used by domestic police forces around the world as a crowd control device, despite its use in warfare being banned by the Chemical Weapons Convention of 1997
The gas was notably used in Ferguson, Missouri during the recent disturbances there in 2014
The American Library of Medicine says of its effects: ‘The eye is the most sensitive organ in riot control because CS causes epiphora, blepharospasm, a burning sensation, and visual problems.
‘Coughing, increased mucous secretion, severe headaches, dizziness, dyspnoea, tightness of the chest, difficulty breathing, skin reactions, and excessive salivation are common.
‘The onset of symptoms occurs within 20 to 60 seconds, and if the exposed individual is placed in fresh air these findings generally cease in 10 to 30 minutes.’
The tear was used in Berkeley, California, on May 21, 1969, what is now known as Bloody Thursday.
Later in the video, several soldiers are shown out in the field as a cloud of CS gas is released on their position, with the men being told they are allowed to put on gas masks when they feel it is appropriate
Developed by two students in 1928 at an American university, CS gas was first tested by the British in the 1950s and 60s before being picked up by the Americans
New recruits to branches of the US military still have to take part in the exercise to this day, though it is done in a far more controlled environment
During a memorial for student James Rector, who was shot and killed by police, CS gas was dropped directly on a trapped crowd.
With no escape possible, dozens of people, including children, were injured during the panic.
It was notably used in Ferguson, Missouri, during protests in 2014, and was also used by police in Pittsburgh in 2009 to disperse crowds gathered outside the G20 summit in the city.
In Britain its use is far less frequent, with very few instances of police using it on the public.
It was used in the Iranian embassy siege in 1980 and during the Toxteth riots in Liverpool in 1981.