Tear gas

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Tear gas in use in France 2007
Exploded tear gas canister in the air in Greece

Tear gas, also known as a lachrymatory agent or lachrymator (from

CN gas (phenacyl chloride), bromoacetone, xylyl bromide and Mace
(a branded mixture).

While lachrymatory agents are commonly deployed for riot control by law enforcement and military personnel, its use in warfare is prohibited by various international treaties.[NB 1] During World War I, increasingly toxic and deadly lachrymatory agents were used.

The short and long-term effects of tear gas are not well studied. The published peer-reviewed literature consists of lower quality evidence that does not establish causality. More rigorous research is needed.[1] Exposure to tear gas agents may produce numerous short-term and long-term health effects, including development of respiratory illnesses, severe eye injuries and diseases (such as traumatic optic neuropathy, keratitis, glaucoma, and cataracts), dermatitis, damage of cardiovascular and gastrointestinal systems, and death, especially in cases with exposure to high concentrations of tear gas or application of the tear gases in enclosed spaces.[2]

Effects

2-chlorobenzalmalononitrile
is the active agent in CS gas.

Tear gas generally consists of aerosolized solid or liquid compounds (bromoacetone or xylyl bromide), not gas.[2] Tear gas works by irritating mucous membranes in the eyes, nose, mouth and lungs. It causes crying, sneezing, coughing, difficulty breathing, pain in the eyes, and temporary blindness. With CS gas, symptoms of irritation typically appear after 20 to 60 seconds of exposure[3] and commonly resolve within 30 minutes of leaving (or being removed from) the area.

Risks

As with all non-lethal or less-lethal weapons, there is a risk of serious permanent injury or death when tear gas is used.[1][4][5][2] This includes risks from being hit by tear gas cartridges that may cause severe bruising, loss of eyesight, or skull fracture, resulting in immediate death.[6] A case of serious vascular injury from tear gas shells has also been reported from Iran, with high rates of associated nerve injury (44%) and amputation (17%),[7] as well as instances of head injuries in young people.[8] Novel findings suggest that menstrual changes are one of the most commonly reported health issues in women.[1]

While the medical consequences of the gases themselves are typically limited to minor

eye injuries involving scarring of the cornea can lead to a permanent loss in visual acuity.[12] Frequent or high levels of exposure carry increased risks of respiratory illness.[2]

In the

The majority (2116; 93.8%) of protestors who reported exposure to tear gas during the 2020 protests in Portland, Oregon (USA) reported physical (2114; 93.7%) or psychological (1635; 72.4%) health issues experienced immediately after (2105; 93.3%) or days following (1944; 86.1%) the exposure. The majority (1233; 54.6%) of respondents who reported exposure to tear gas during the 2020 protests in Portland, Oregon (USA) have also reported receiving or planning to seek medical or mental healthcare for their tear gas-related health issues.[1] It has been shown that health issues associated with the exposure to tear gas are often require medical attention.[1]

Site of action

CN gas (phenacyl chloride) and bromoacetone in rodent models.[16][17]

Use

Warfare

During World War I, various forms of tear gas were used in combat and tear gas was the most common form of chemical weapon used. None of the belligerents believed that the use of irritant gases violated the Hague Convention of 1899 which prohibited the use of "poison or poisoned weapons" in warfare. Use of chemical weapons escalated during the war to lethal gases, after 1914 (during which only tear gas was used).

The US

Chemical Warfare Service developed tear gas grenades for use in riot control in 1919.[18]

Use of tear gas in interstate warfare, as with all other chemical weapons, was prohibited by the Geneva Protocol of 1925: it prohibited the use of "asphyxiating gas, or any other kind of gas, liquids, substances or similar materials", a treaty that most states have signed. Police and civilian self-defense use is not banned in the same manner.[19]

Tear gas was used in combat by Italy in the

Israel–Palestine conflict.[20][21]

Tear gas exposure is an element of military training programs, typically as a means of improving trainees' tolerance to tear gas and encouraging confidence in the ability of their issued protective equipment to prevent chemical weapons exposure.[22][23][24]

Riot control

Certain lachrymatory agents, most notably tear gas, are often used by police to force compliance.[5] In some countries (e.g., Finland, Australia, and United States), another common substance is mace. The self-defense weapon form of mace is based on pepper spray which comes in small spray cans. Versions including CS are manufactured for police use.[25] Xylyl bromide, CN and CS are the oldest of these agents. CS is the most widely used. CN has the most recorded toxicity.[3]

Typical manufacturer warnings on tear gas cartridges state "Danger: Do not fire directly at person(s). Severe injury or death may result."[26] Tear gas guns do not have a manual setting to adjust the range of fire. The only way to adjust the projectile's range is to aim towards the ground at the correct angle. Incorrect aim will send the capsules away from the targets, causing risk for non-targets instead.[27]

Tear gas during the repression of the protest against the El Khomri law (labour law) in Paris, France, 2016.
Tear gas during the repression of the protest against the El Khomri law (labour law) in Paris, France, 2016.

Counter-measures

A variety of protective equipment may be used, including

swimming goggles and adapted water bottles, as well as covering as much skin as possible.[28][29][30]

Activists in United States, the Czech Republic, Venezuela and Turkey have reported using

baking soda.[34] There have also been reports of these antacids being helpful for tear gas,[35] and for capsaicin-induced skin pain.[36]

During the

Chilean protesters of Primera Línea have specialized individuals collecting and extinguishing the tear gas grenades. Others act as tear gas medics, while yet another group, the so-called shield-bearers, protect the protesters from the direct physical impact of the grenades.[38]

Treatment

A paramedic tending to an opposition protester during the 2014 Venezuelan protests
Fabiola Campillai, a Chilean woman left blind in both eyes by a direct hit of a tear-gas grenade in her face.

There is no specific antidote to common tear gases.[3][39] At the first sign of exposure or potential exposure, masks are applied when available. People are removed from the affected area when possible.[40][41] Immediate removal of contact lenses has also been recommended, as they can retain particles.[41][39]

Decontamination is by physical or mechanical removal (brushing, washing, rinsing) of solid or liquid agents. Water may transiently exacerbate the pain caused by

amphoteric salt solution, a first aid product for chemical splashes, may help with ocular burns or chemicals in the eye.[42][44]

Bathing and washing the body vigorously with soap and water can remove particles that adhere to the skin. Clothes, shoes and accessories that come into contact with vapors must be washed well since all untreated particles can remain active for up to a week.[45] Some advocate using fans or hair dryers to evaporate the spray, but this has not been shown to be better than washing out the eyes and it may spread contamination.[39]

Anticholinergics can work like some antihistamines as they reduce lacrymation and decrease salivation, acting as an antisialagogue, and for overall nose discomfort as they are used to treat allergic reactions in the nose (e.g., itching, runny nose, and sneezing).[citation needed]

Oral analgesics may help relieve eye pain.[39]

Most effects resulting from riot-control agents are transient and do not require treatment beyond decontamination, and most patients do not need observation beyond 4 hours. However, patients should be instructed to return if they develop effects such as blistering or delayed-onset shortness of breath.[40]

Home remedies

Vinegar, petroleum jelly, milk and lemon juice solutions have also been used by activists.[46][47][48][49] It is unclear how effective these remedies are. In particular, vinegar itself can burn the eyes and prolonged inhalation can also irritate the airways.[50] Vegetable oil and vinegar have been reported as helping relieve burning caused by pepper spray,[41] Kräuter suggests the usage of baking soda or toothpaste, stating that they trap the particles emanating from the gas near the airways that are more feasible to inhale.[34] A small trial of baby shampoo for washing out the eyes did not show any benefit.[39]

See also

References

Informational notes

  1. ^ E.g. the Geneva Protocol of 1925 prohibited the use of "asphyxiating gas, or any other kind of gas, liquids, substances or similar materials".

Citations

  1. ^
    PMID 33902512
    .
  2. ^ .
  3. ^ .
  4. ^ Heinrich U (September 2000). "Possible lethal effects of CS tear gas on Branch Davidians during the FBI raid on the Mount Carmel compound near Waco, Texas" (PDF). Prepared for The Office of Special Counsel John C. Danforth.
  5. ^
    PMID 2501523. Archived from the original
    (PDF) on 29 October 2013.
  6. .
  7. .
  8. .
  9. .
  10. .
  11. .
  12. .
  13. ^ "INDH se querella por homicidio frustrado contra Carabineros en favor de trabajadora que habría perdido visión de ambos ojos". Instituto Nacional de Derechos Humanos (in Spanish). 27 November 2020. Retrieved 29 June 2020.
  14. ^ "INDH presenta querella por joven que perdió un ojo por lacrimógena en año nuevo en Plaza Italia". Instituto Nacional de Derechos Humanos (in Spanish). 8 January 2020. Retrieved 29 June 2020.
  15. ^ "INDH se querella por lesión a profesor que perdió un ojo en Valparaíso". Instituto Nacional de Derechos Humanos (in Spanish). 4 January 2020. Retrieved 29 June 2020.
  16. PMID 19036859
    .
  17. .
  18. .
  19. ^ "Practice Relating to Rule 75. Riot Control Agent". ihl-databases.icrc.org/. IHL Database. Retrieved 7 July 2020.
  20. ^ 100 Years of Tear Gas, The Atlantic, August 16, 2014
  21. ^ "Israeli Soldiers Assault Activists, Palestinians Bringing Water to West Bank Village". Haaretz.
  22. ^ "Co. G recruits use new gas mask in confidence chamber". tecom.marines.mil. Marine Corps Websites. Retrieved 25 October 2019.
  23. ^ "Recruits feel effects of Confidence Chamber". mcrdsd.marines.mil. Marine Corps Websites. Retrieved 25 October 2019.
  24. ^ "MoD confirms army CS gas investigation". Politics.co.uk. 13 May 2006. Archived from the original on 9 October 2013. Retrieved 6 January 2013.
  25. ^ "Mace pepper spray". Mace (manufacturer). Archived from the original on 5 August 2013. Retrieved 21 February 2014.
  26. ^ Smith E (28 January 2011). "Controversial tear gas canisters made in the USA". Africa. CNN.
  27. Turkish Doctors' Association, 16 June 2013, TÜRK TABİPLERİ BİRLİĞİ'NDEN ACİL ÇAĞRI!
  28. ^ "Gezi park protesters bring handmade masks to counter police tear-gas rampage". Hürriyet Daily News. 31 May 2013.
  29. ^ "Protecting yourself from tear gas: INSI". newssafety.org. Archived from the original on 25 July 2021. Retrieved 28 November 2020.
  30. ^ a b Livingston, Mercey (2 June 2020). "Here's what to do if you get exposed to tear gas". CNET. Retrieved 28 November 2020.
  31. ^ Ferguson D (28 September 2011). "'Maalox'-and-water solution used as anti-tear gas remedy by protesters". Raw Story. Archived from the original on 23 August 2014. Retrieved 4 June 2013.
  32. ^ "Medical information from Prague 2000". Archived from the original on 18 October 2014.
  33. ^ Ece Temelkuran (3 June 2013). "Istanbul is burning". Occupy Wall Street.
  34. ^ a b "Prof USB Mónica Kräuter, Cómo reaccionar ante las bombas lacrimógenas". Tururutururu (in European Spanish). 26 May 2017. Archived from the original on 7 November 2017. Retrieved 1 November 2017.
  35. ^
    S2CID 7870564
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  36. .
  37. Japan Times. 9 August 2019. Archived from the original
    on 7 November 2019. Retrieved 27 October 2019.
  38. ^ Claude, Magdalena (6 January 2020). "Retrato de un clan de la Primera Línea". CIPER Chile (in Spanish). Retrieved 6 March 2020.
  39. ^
    PMID 26808721
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  40. ^ a b c "Riot-Control Chemical Agents - Injuries; Poisoning". MSD Manual Professional Edition. Retrieved 4 October 2022.
  41. ^
    PMID 26554271
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  42. ^ .
  43. .
  44. .
  45. ^ "Who, What, Why: How dangerous is tear gas?". BBC. 25 November 2011. Retrieved 31 May 2017.
  46. ^ Agence France-Press. "Tear gas and lemon juice in the battle for Taksim Square". NDTV. Retrieved 23 June 2013.
  47. ^ Doyle M (24 June 2013). "Turks in Pittsburgh concerned for their nation". Pittsburgh Post-Gazette.
  48. ^ Arango T (15 June 2013). "Police Storm Park in Istanbul, Setting Off a Night of Chaos". The New York Times.
  49. ^ Hughes G (25 June 2013). "Denbigh man tear gassed". The Free Press. Archived from the original on 28 June 2013. Retrieved 28 June 2013.
  50. Toxics Use Reduction Institute, UMAss Lowell. Archived from the original
    on 24 June 2013. Retrieved 22 June 2013.

Further reading

External links