CS gas: Difference between revisions
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CS is used by many police forces within the USA, for example the [[NYPD]], it was most famously used as one of a number of techniques used by [[FBI]] law enforcement officials in the 1993 [[Waco Siege]]. |
CS is used by many police forces within the USA, for example the [[NYPD]], it was most famously used as one of a number of techniques used by [[FBI]] law enforcement officials in the 1993 [[Waco Siege]]. |
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Members of the [[United States|US]] armed forces are often exposed to CS during initial training to show the importance of proper wearing of a [[gas mask]] as well as to develop confidence in the equipments effectiveness (many soldiers misattribute the feeling of air rushing into the mask as being the |
Members of the [[United States|US]] armed forces are often exposed to CS during initial training to show the importance of proper wearing of a [[gas mask]] as well as to develop confidence in the equipments effectiveness (many soldiers misattribute the feeling of air rushing into the mask as being the caused by a poor seal). As the agent's presence quickly reveals improper fit or seal of the mask's rubber gaskets against the face, it is sometimes used during training refresher courses or equipment maintenance exercises as well. |
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===Elsewhere=== |
===Elsewhere=== |
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Revision as of 04:53, 26 August 2006
| CS gas | |
|---|---|
| General | |
| IUPAC | 2-Chlorobenzalmalononitrile |
| Other names | CS Gas
Tear gas ortho-chlorobenzylidene malononitrile Propanedinitrile, [(2-chlorophenyl)methylene] Malononitrile, (o-chlorobenzylidene) β,β-Dicyano-o-chlorostyrene (o-Chlorobenzal)malononitrile (o-Chlorobenzylidene)malononitrile 2-Chlorobenzylidenemalononitrile (o-Chlorobenzylidene)malonitrile o-Chlorobenzylidenemalonic nitrile NCI-C55118 USAF KF-11 2-Chloro BMN b, b-Dicyano-O-chlorostyrene 2-Chlorobenzylidenemaloninitrile Propanedinitrile, 2-2-chlorobenzylidene 2-(2-Chlorobenzylidene)malononitrile |
| Molecular formula | C10H5Cl N2 |
| Molar mass | 188.6 g/mol [1] |
| Appearance | White crystalline powder, Colourless gas when burned. |
| CAS number | [2698-41-1] |
| Properties [2] | |
| Density/phase | 1.04 g/cm3, solid |
| Soluble | MiBK, hexane, benzene, methylene chloride, acetone, dioxane, ethyl acetate, and pyridine. |
| Insoluble | ethanol, water |
| Melting point | 93°C, (366.15 K), (199.4 °F) |
| Boiling point [3] | 310 °C, (583.15 K), (590 °F) |
| Vapor pressure | ([[1 10-3 m|mm]] Hg) 3.4 x 10-5 at 20°C |
| Volatility | 0.71 mg/m3 at 25°C |
| Toxicity Values | ICt50 = 10 to 20 mg-min/m3 LCt50 = 61,000 mg-min/m3 |
| Exposure Limits | Workplace Time-Weighted Average: 0.4 mg/m3 General Population Limits: No standard identified |
| Related compounds SDBS |
5-chloro-2-quinolinecarbonitrile 6-chloro-2-quinolinecarbonitrile 7-chloro-2-quinolinecarbonitrile |
CS or 2-chlorobenzalmalononitrile (chemical formula: C10H5ClN2) is a substance that is used as a riot control agent and is usually claimed to be non-lethal by the forces who use it. CS was discovered by two Americans, Ben Carson and Roger Staughton in 1928, the first letters of the scientists' surname giving us the name of the substance, 'CS' [4]. It was developed and tested secretly at Porton Down in Wiltshire, England. Apparently this testing occurred in the 1950s and 1960s when CS was used firstly on animals, then subsequently on British Army servicemen volunteers. Notably CS has a limited effect on animals due to "under-developed tear-ducts and protection by fur". [5].
Production
It is synthesized by the reaction of 2-chlorobenzaldehyde and malononitrile via the Knoevenagel condensation:
- ClC6H4CHO + H2C(CN)2 → ClC6H4CHC(CN)2 + H2O
The reaction is catalysed with weak base like piperidine or pyridine. The production method has not changed since the substance has been discovered by B Carson and R Staughton.[6] Other bases, solvent free methods and microwave promotion have been suggested to improve the production of the substance.[7]
The physiological properties have been discovered already by the chemists first synthesising the compound in 1928: "Physiological Properties.-Certain of these dinitriles have the effect of sneeze and tear gases. They are harmless when wet but to handle the dry powder is disastrous. (sic)"[6]
'CS Gas' - a misnomer
In common parlance CS is referred to as 'CS gas' or 'Tear gas', however this description is incorrect because 2-chlorobenzalmalononitrile is a solid at room temperature, not a gas. A variety of techniques have been used to make this solid usable as an airborne irritant. For example in Waco, Texas, CS was dispersed in droplet form. CS was dissolved in the organic solvent Methylene chloride (MC) and when this evaporated, the CS crystallized into fine particles [1].
It is worth noting that many types of tear gas have been produced with effects ranging from mild tearing of the eyes to immediate vomiting and prostration. CN and CS are the most widely used and known, but around 15 different types of tear gas tested worldwide. CS has become the most popular due to its strong effect and lack of toxicity in comparison with other similar chemical agents. The effect of CS on a person will depend on whether it is packaged as a solution, or if it is an aerosol; the size of solution droplets and the size of the CS particulates after evaporation, are factors determining its effect on the human body. Certain individuals however have been found to be particularly sensitive to CS and or the organic solvents that are utilised. Studies on the use of CS on the public have noted that it may be ineffective against persons who are either mentally ill or who are under the effects of alcohol [8].
Persons which had contact with CS sometimes develop allergic contact dermatitis[9], even with blisters and crust[10][11] Studies show that most of the effects are of a relative short term, but individuals notice some mild effects even after months.[12]
Preparations
- Melted and sprayed in the molten form.
- Dissolved in organic solvent.
- CS2 dry powder (CS2 is a siliconized, micro-pulverized form of CS).
- CS from thermal grenades by generation of hot gases [1].
CS incapacitant spray
CS Incapacitant Spray is used as a temporary incapacitant, to subdue attackers, or persons who are violently aggressive, by many police forces. The chemical reacts with moisture on the skin and in the eyes causing a burning sensation and the immediate forceful shutting of the eyes. Reported effects can include tears streaming from the eyes, running nose full of mucus, burning in the nose and throat areas, disorientation, dizziness and restricted breathing. In highly concentrated doses it can also induce severe coughing and vomiting.
Although predominantly used by police forces it has also been used in criminal attacks in various countries.[13] [14] [15] [16].
CS is banned from use in war by the 1997 Chemical Weapons Convention (signed 1993), as its use could be a trigger for full scale chemical warfare. However, domestic police use of it is legal in many countries.
Use geographically
Cyprus
CS was first tested in the field by the British army in Cyprus in 1958. At this time it was known by the code name T792 [17].
Vietnam
It has been reported that thousands of tons of CS gas were used by the U.S. forces in Vietnam to bring Viet Cong into the open [18], other estimates report 15 million pounds of CS being used [19].
Northern Ireland
CS gas was heavily used in the Bogside area of Derry, Northern Ireland during the "Battle of the Bogside", a two-day riot in August, 1969. A total of 1,091 canisters containing 12.5g of CS; and 14 canisters containing 50g of CS, were released in the densely populated residential area [20]. On 30 August the Himsworth Inquiry was set up to investigate the medical effects of its use in Derry. Its conclusions, viewed in the political context of the time, still pointed towards the necessity of further testing of CS gas before being used as a riot control agent. Not long after, the British Army and RUC ceased using CS in Northern Ireland. Up to this point, it had been used in crowd control scenarios in Derry and Belfast.
Iraq
Iraq successfully developed CS during the 1970s and during the 1980s produced tons of the substance firstly at Salman Pak and later at al-Muthanna [21]. Saddam Hussein used CS against the Kurds in his own country and against Iran during the Iran-Iraq War.
England & Wales
CS tear gas was first used in mainland Britain to quell rioting in the Toxteth area of Liverpool in 1981. [22]
Personal incapacitant spray (PIS) was sanctioned for use by Police in England and Wales in 1995. [23] The CS preparation in this case is CS dissolved in the organic solvent MiBK, or methyl iso-butyl ketone, an industrial de-greasing agent. The propellant used in this preparation is Nitrogen [24].
It has been noted that the solvent MiBK is itself harmful, and can cause inflammation, dermatitis, burns to the skin & liver damage. [25].
A six month trial by 16 police forces in England began on the 1st March 1996. Only two weeks later, on the 16th of March 1996, a Gambian asylum seeker, Ibrahima Sey was taken to Ilford Police Station in East London. Whilst incapacitating the man, police sprayed him with CS and held him on the ground for over 15 minutes. The man died, the case was taken to court and although a verdict of "Unlawful Killing" was given by the jury at the end of the inquiry into his death, no charges were brought against any member of the police force [26].
The forces that do use the PIS in the UK require that police constables should themselves be sprayed with a 3% dissolved CS, during self-defence training, in order for them to be able to be authorised to carry it as personal protection equipment. They are also trained in helping the incapacitated person recover quickly once successfully restrained. Most forces currently issue CS Spray to its officers, but there has been a recent move for a few forces to issue PAVA Spray (pelargonic acid vanillylamide aka nonivamide).
Notably the CS spray used by UK police has 5 times as much CS as the spray used by American police forces (5% dissolved CS and 1% CS respectively). [27]
In 1999 the UK mental health charity MIND called for a suspension in its use until it is fully tested and there is proof that CS is safe. [28]
More recently, in February 2006 there have been calls to have CS spray banned in the UK after Dan Ford, from Wareham in Dorset, was permanently facially scarred after being sprayed in the face with a police CS canister. Mr Ford was subsequently advised by doctors to stay out of sunlight for at least 12 months. About the incident, his cousin, Donna Lewis, was quoted as saying:
"To look at him, it was like looking at a melting man, with liquid oozing from his face." [29]
However it is not yet confirmded that Mr Ford's injury is a reaction from being exposed to police CS spray or whether another non-police chemical exposure has caused the injury and an investigation is ongoing.
USA
CS is used by many police forces within the USA, for example the NYPD, it was most famously used as one of a number of techniques used by FBI law enforcement officials in the 1993 Waco Siege.
Members of the US armed forces are often exposed to CS during initial training to show the importance of proper wearing of a gas mask as well as to develop confidence in the equipments effectiveness (many soldiers misattribute the feeling of air rushing into the mask as being the caused by a poor seal). As the agent's presence quickly reveals improper fit or seal of the mask's rubber gaskets against the face, it is sometimes used during training refresher courses or equipment maintenance exercises as well.
Elsewhere
CS was used in large quantities to quell a peaceful protest in Lusaka, Zambia in July 1997, Amnesty International reported that it had been manufactured by the UK company Pains-Wessex. Subsequently, Amnesty called for an export ban when the receiving regime is either not fully trained in the use of CS, or had shown usage "contrary to the manufacturer’s instructions". [30]
In September 2000, the Guardian Newspaper revealed how a UK company, HPP, used legal loopholes to export CS to a private security company in Rwanda, in breach of United Nations sanctions. [31] The Guardian also reported that CS was used by the Hutu militia in Rwanda to flush Tutsis out of buildings before hacking them to death.
CS has been used by the government in South Africa; by Israel against Palestinians; by the South Korean government in Seoul, and during the Balkan conflicts.
CS tear gas was used at the G8 protests in Genoa, Italy [32] and Quebec, Canada [33] during the FTAA anti-globalization demonstrations during the Quebec City Summit of the Americas.
The Australian Army trains its soldiers with CS gas in a manner similar to that of the USA. It is a basic part of NBC (nuclear, bacteriological, chemical) training. Gas is released by burning tablets, usually in a tent, and soldiers exposed to it on three occasions. During the first two exposures the soldier enters the tent wearing a gas mask. During the first exposure he removes his gas mask and leaves the tent. During the second exposure he must release the mask, receive facial exposure, then replace and clear the mask. In the third exposure he enters the tent unprotected, must fit and clear the gas mask before leaving. Symptoms are a burning sensation on any moist skin, whether due to perspiration or other fluids such as tears or in the nasal membranes.
Toxicity
Although described as a non-lethal weapon for crowd control, many studies have raised doubts about this classification. As well as creating severe pulmonary damage, CS can also significantly damage the heart and liver. [34]
On 28 September 2000, Prof. Dr. Uwe Heinrich released a study commissioned by John C. Danforth, of 'The Office of Special Counsel', to investigate the use of CS by the FBI at the Branch Davidians' Mount Carmel compound. In summary, he concluded that the lethality of CS used would have been determined mainly by two factors: whether gas masks were used, and whether the occupants were trapped in a room. He suggests that if no gas masks were used and the occupants were trapped, then:
"...there is a distinct possibility that this kind of CS exposure can significantly contribute to or even cause lethal effects." [1]
Many reports have associated CS exposure with miscarriages [34], this is consistent with its reported clastogenic effect (abnormal chromosome change) on mammalian cells.
When CS is metabolized, cyanide can be detected in human tissue. [34] According to the United States Army Center for Health Promotion and Preventive Medicine, CS emits "very toxic fumes" when heated to decomposition, and at specified concentrations CS gas is an immediate danger to life and health. They also state that those exposed to CS gas should seek medical attention immediately[1].
Decontamination
Decontamination can be performed by washing with an alkaline solution of water and 5% sodium bisulfite.[5]
See also
References
- ^ a b c d Study by Uwe Heinrich Documents the chemistry of CS and its effects on the body. 09 March ,2006)
- ^ U.S. Army Center for Health Promotion and Preventive Medicine Detailed Facts About Tear Agent O-Chlorobenzylidene Malononitrile (CS) (pdf)09 March ,2006)
- ^ www.wombles.org.uk Article on pepper spray and tear gas.09 March ,2006)
- ^ columbia.thefreedictionary.com/
- ^ a b Zarc International Inc. CS factsheet
- ^ a b Corson BB, Stoughton RW (1928). "Reactions of Alpha, Betha-Unsaturated Dinitriles". J Am Chem Soc. 50: 2825–2837. doi:10.1021/ja01397a037.
- ^ Pande A, Ganesan K, Jain AK, Gupta PK, Malhotra RC (2005). "Novel Eco-Friendly Process for the Synthesis of 2-Chlorobenzylidenemalononitrile and ITS Analogues Using Water As a Solvent". Org Proc Res Develop. 9: 133–136.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ POLICE COMPLAINTS AUTHORITY "SAFER RESTRAINT" - April 2002 (pdf)
- ^ Sommer S, Wilkinson SM (1999). "Exposure-pattern dermatitis due to CS gas". Contact Dermatitis. 40: 46–47.
- ^ Karalliedde L, Wheeler H, MacLehose R, Murray V (2000). "Possible immediate and long-term health effects following exposure to chemical warfare agents". Public Health. 114: 238–248. doi:10.1038/sj.ph.1900659. PMID 10962584.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Weir E (2001). "The health impact of crowd-control agents". J Am Med C. 164: 1889–1890. PMID 11450291.
{{cite journal}}: Cite has empty unknown parameter:|1=(help) - ^ Karagama YG , Newton JR, Newbegin C J R (2003). "Short-term and long-term physical effects of exposure to CS spray". J Royal Soc MedMed C. 96A: 172–174. PMID 12668703.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Guardian Unlimited CS gas attack by former pupil injures 68 children , October, 1999, Liverpool
- ^ irishhealth.com Gas attack at Dublin hospital, May 2004
- ^ BBC News online Shopkeeper attacked with CS gas, December 2005, Manchester
- ^ BBC News online Car thieves spray gas at motorist, January 2006, Oxted
- ^ Final Report of the Expert Panel to Review SAS Veterans’ Health Concerns 2003(pdf)
- ^ totse.com The Human Aversion to Killing and the Lie of "Non-Lethal" Weapons
- ^ It was also used by the North Vietnamese forces in some battles like Hue in 1968 or during the Easter Offensive in 1972. The Austin Chronicle FBI's Use of Tear Gas Questioned at Davidian Trial, Lethal Weapon, by Robert Bryce.
- ^ Dr Raymond McClean (1997). The Road To Bloody Sunday (revised edition). Guildhall: Printing Press. ISBN 0-946451-37-0. (extracts available online)
- ^ www.iraqwatch.org
- ^ BBC News online Riots in Toxteth
- ^ Euripidou E, MacLehose R, Fletcher A (2004). "An investigation into the short term and medium term health impacts of personal incapacitant sprays. A follow up of patients reported to the National Poisons Information Service (London)". Emerg Med J. 21 (5): 548–52. PMID 15333526.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ The Police Complaints Authority CS SPRAY: INCREASING PUBLIC SAFETY, March 2000. (pdf)
- ^ Safety (MSDS) data for methyl isobutyl ketone The Physical and Theoretical Chemistry Laboratory Oxford University
- ^ INQUEST, 1997 Report on the death in Police custody of Ibrahima Sey
- ^ Southward RD (2000). "CS incapacitant spray". J Accid Emerg Med. 17 (1): 76. PMID 10659007.
- ^ BBC News online Statement made by MIND
- ^ BBC News online Report on Dan Ford.
- ^ Amnesty International Report Stopping the Torture Trade (pdf)
- ^ Guardian Unlimited British firms trade in torture
- ^ italy.indymedia.org Laura Tartarini, lawyer of Genova Legal Forum
- ^ www.nowtoronto.com Foggy Over Tear Gas Safety - Enzo Di Matteo
- ^ a b c Tear Gas: Harassing Agent or Toxic Chemical Weapon? The Journal of the American Medical Association
External links
- Gas Chromatography NIST
- U.S. Army Center for Health Promotion and Preventive Medicine General Facts About Tear Agent O-Chlorobenzylidene Malononitrile (CS) {pdf}
- PATTEN REPORT RECOMMENDATIONS 69 AND 70 RELATING TO PUBLIC ORDER EQUIPMENT A Paper prepared by the Steering Group led by the Northern Ireland Office - April 2001
- COMMITTEES ON TOXICITY, MUTAGENICITY AND CARCINOGENICITY OF CHEMICALS IN FOOD, CONSUMER PRODUCTS AND THE ENVIRONMENTSTATEMENT ON 2-CHLOROBENZYLIDENE MALONONITRILE (CS) AND CS SPRAY, September 1999. (pdf)
- Journal of Non-lethal Combatives, Jan 2003 Noxious Tear-Gas Bomb Mightier in Peace than in War.
- www.thisisessex.co.uk Officers sprayed by their own CS.
- "Crowd Control Technologies : An Assessment Of Crowd Control Technology Options For The European Union" - The Omega Foundation (pdf)
- HEALTH AND SAFETY IN POLICING University of Nottingham paper on CS use in the UK.
- BBC 'wiki' site - entry on CS gas
- eMedicine Information on irritants: Cs, Cn, Cnc, Ca, Cr, Cnb, PS
- PBS article on CS use in Waco.
- How to combat the effects
- PHR Publication The Use of Tear Gas in the Republic of Korea - A Report by Health Professionals.