TRUE OR FAKE. Is tear gas toxic in the long term?

We know the immediate dangers of tear gas: intense irritation and difficulty in breathing. But would it also be toxic in the long term? After going through numerous studies and taking samples, the doctor of biology Alexander Samuel came to the conclusion that a continuous molecule in tear gas turns into cyanide. “And this cyanide, at the concentration that I have been able to measure in any case, is dangerous enough to cause damage to the brain, liver and kidneys”he explains.

A study carried out on animals actually demonstrated that tear gas could turn into cyanide once ingested. For the various toxicologists interviewed by France Info, this does not mean that the situation necessarily occurs in humans.

Dissatisfied studies according to critics of tear gas

Pr. Bruno Megarbane, head of the medical and toxicological resuscitation department at the Lariboisière hospital in Paris, specifies in particular “that the experimental conditions do not correspond at all to human exposure”and that the toxicity of cyanide, which is always immediate, has no long-term effects.

Alexander Samuel says that the studies cited were not carried out under the right conditions. One was made in particular after an exposure of up to 1.5 mg/M3 of tear gas. However, during the Portland riots in the United States, demonstrators were exposed to 4.5 mg/m3. Asked about this by email, Dr. Robert Garnier, toxicology doctor, explains that there is no “in practice no known case of human hydrocyanic poisoning after exposure to CS [gaz lacrymogène]”. Toxicologists therefore ensure that the toxicity of the gas is immediate, and solely linked to its irritant power. The answer does not satisfy the detractors of the CS, who ask for more precise studies on the subject.