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168 18Accid Emerg Med 1999;16:168-170

CS exposure-clinical effects and management J Accid Emerg Med: first published as 10.1136/emj.16.3.168 on 1 May 1999. Downloaded from Elspeth Worthington, Patrick A Nee

Abstract properties, namely chloroacetophone (CN), The number of people exposed to CS , and . spray presenting to accident and emer- The mechanism ofaction of CS in humans is gency departments is on the increase. Its not fully understood. Hydrochloric acid is pro- effects, though usually minor and short duced by reduction of chloride ions on the skin lived, involve several systems and can and this may cause marked local irritation.2" occasionally be life threatening. It is CS alkylates intracellular sulphydryl groups, therefore important that staff are able to competitively inhibiting the enzymes depend- manage these patients and know when and ent on this group."' There is also a cyanide how to protect themselves and others from moiety within CS molecule. Although this may further contamination. contribute to the local irritative effects of the (7Accid Emerg Med 1999;16: 168-170) compound it is not thought to enter the central nervous system under normal conditions of Keywords: CS spray; incapacitant; emergency manage- exposure.2 8 ment CS sprays were designed for use by the to incapacitate violent opponents who The use of hand held defence sprays to could not be restrained without risk to life.9 incapacitate violent offenders has become Short, low dose exposures have the required widespread among many UK police forces. rapid onset deterrent qualities with few medi- Accident and emergency personnel are there- cal complications.5 fore increasingly treating patients who have Police guidelines specify that a warning must been exposed to CS spray. A basic understand- be given before using the spray and that it ing of its clinical effects is essential to permit should not be administered at a range of less the appropriate triage and emergency care of than 3 feet due to increased risks of toxicity, such patients. especially to the eyes. After the use of CS spray O-chlorobenzylidene malonitrile was named the victims should be promptly removed from CS after the two chemists Corson and the contaminated area to avoid prolonged Stoughton who synthesised the compound in exposure. During transportation the prone 1928. In its natural state it is a fine white solid position should be avoided because of the dan- similar to talcum powder with a pepper-like ger of asphyxia and police are advised to leave odour. Its is represented in the windows open to aid dispersion.'0 When in police custody, attendance by a police surgeon fig 1. It can be disseminated as a fine dust via http://emj.bmj.com/ an or, when mixed with a pyrotechnic is mandatory for anyone suffering any compli- compound, as a smoke or fog of minute parti- cations as a result of CS spray exposure.9 cles from a or canister. Guidelines for police surgeons specify that The "CS incapacitant spray" currently in anyone suffering with a pre-existing pulmonary use by the UK police forces contains a solution or cardiac condition should be examined and of CS in a of monitored by a doctor and referred to a hospi- propelled by compressed . In legal tal as necessary.' terms this is a and requires a licence for on October 4, 2021 by guest. Protected copyright. its possession.' In minute doses it acts as a Effects severe irritant and lacrimator causing a severe The irritant effects of CS are of rapid onset local reaction within seconds of contact with even in low concentrations and are short lived mucous membranes and skin. There are other (15-30 minutes) if individuals are moved into with a similar fresh air,' though the time for complete recov- compounds range of irritant ery has been questioned.'0 Area decontamina- Accident and tion is not required after the use of CS , Emergency CN however the incapacitant spray used by the Department, Royal police adheres to surfaces within its vicinity University and when used indoors people are at risk of Hospital recontamination if the area is not thoroughly E Worthington CN cleaned. Both agents are widely held to be safe Accident and when used appropriately; irritant symptoms Emergency are produced at concentrations at least 2600 Department, Whiston times lower than the .6 There are Hospital, Prescot, said to be no additional hazards in elderly sub- Merseyside L35 5DR jects or those with a history of allergies, hyper- P A Nee tension, jaundice, or hepatitis." Correspondence to: Mr Nee. EYES Figure 1 Chemical structure ofo-chlorobenzylidene CS and similar agents are known as lacrima- Accepted 11 February 1999 malonitrate (CS). tors. They are intended for use against an CS exposure 169

aggressor and their main target is the eyes. teratogenic.4 20 No increase in the incidence of They cause an intense irritation of exposed spontaneous abortions, stillbirths, or congeni- mucous membranes resulting in lacrimation, tal abnormalities has been found in the

blepharospasm, conjunctival erythema, and geographical areas of CS gas use." There have J Accid Emerg Med: first published as 10.1136/emj.16.3.168 on 1 May 1999. Downloaded from periorbital oedema.5 8 These symptoms are been no reported cases of CS gas or spray pre- more severe in those victims wearing contact cipitating seizures in people with epilepsy nor lenses. Permanent eye damage is uncommon of any significant psychiatric disturbance at- and there are no reported cases of blindness in tributed to its use.49 humans as a consequence of exposure to CS gas or spray.5 However, raised intraocular CHILDREN pressure may occur and may precipitate acute There are only a few case reports ofinfants and angle closure glaucoma. Longer term potential children exposed to CS gas and its effect seems problems include cataracts, vitreous haemor- similar to that in adults. Chemical pneumonitis rhage, and traumatic optic neuropathy.'2 was found in a toddler after prolonged exposure, but a full recovery was made.' RESPIRATORY On inhalation the spray initially causes nasal Complications congestion and rhinorrhoea. As it reaches the CS spray is thought to be a safe agent when mouth its burning acidic precedes the protocols governing its use are adhered to. Pro- stinging effect on the throat. Progression into tocol violations are usually concerned with the the larynx, trachea, and pulmonary tree can duration and concentration of exposure and cause coughing, the production of copious failure to remove victims from the contami- secretions, bronchospasm, and nated area. Adverse reactions are more fre- laryngospasm.5 8 Excessive exposure can result quent and more severe when the spray is used in pulmonary oedema, which may be delayed in enclosed spaces.4 12 14There are no reports of up to 24 hours, chemical pneumonitis or con- death directly attributable to CS gas or spray in gestive heart failure.5 Patients with pre-existing the current literature.61' respiratory disease such as or chronic Most safety studies have been performed in obstructive pulmonary disease are at particular North America where CS gas has been used by risk of more severe reactions and exacerbation police forces for many years.6 The effective of their underlying conditions.4 1314 There are deterrent concentration in adult subjects is several reports of reactive airways dysfunction 10-20 mg/Mi.6 In higher concentrations there syndrome in previously healthy individuals is an increased risk of longer lasting effects exposed to CS gas, and prolonged cough and such as corneal damage, skin burns, and respi- impaired respiratory function may last for ratory damage. many months.'5 The solvent base of the CS incapacitant spray now being used in the UK is also an irri- SKIN tant to the eyes and the effects it may have on Contact of CS with the skin produces a burn- the skin, that is irritation, erythema, drying, ing sensation and erythema usually settling flaking and blistering, may be delayed in onset within 24 hours. 14 Prolonged contact, espe- for up to eight hours and can last for up to one http://emj.bmj.com/ cially in association with wet skin or clothing, week.' '4 worsens the effect and can result in chemical burns.'6 17 These are usually minor but exten- Management of CS exposure sive damage up to 20% of the body surface On reaching fresh air, recovery from these area has been reported.'7 Allergic contact agents is usually complete in 30 minutes; thus as a result of repeated exposure to the most important early action in managing 14 both CS gas and spray has been reported.3 victims of CS spray exposure is their removal on October 4, 2021 by guest. Protected copyright. from that site into clean areas.4 '4 '9 GASTROINTESTINAL Exposed victims should be placed in a well Gastrointestinal disturbances with loss of ventilated area, preferably with a free flow of air appetite, nausea, vomiting, and diarrhoea have to aid dispersal of the gas and no unprotected occurred after CS gas exposure.5 16 These are attendants downwind. also known effects of the propellant used in the Contamination of the eyes with CS gas police incapacitant spray.'8 Acute hepatocellu- should be treated by blowing dry air directly lar damage and associated enzyme changes onto them with an electric fan if available,12 have also been reported.5 However no evidence however CS spray may require irrigation of the of chronic liver damage has been found in sub- eyes with isotonic fluids or water for its jects exposed to CS gas." complete removal.'4 22 Once the irritant symp- toms settle usually only mild conjunctival OTHER SYSTEMS injection or minor corneal abrasions persist. Experiments in a chemical defence establish- These patients can then be discharged with a ment did not reveal any significant changes to short course of broad spectrum antibiotic eye cardiovascular parameters or to the electrocar- drops. Older subjects should be monitored for diogram except a mild short lived symptoms and signs of acute glaucoma.'2 tachycardia,'9 although in persons with pre- The skin should be showered with soap and existing cardiac disease hypertension may be copious flowing water. Any burns should be exacerbated.' managed in the same way as thermal burns. There is no substantial evidence in animals Topical steroids and antiseptic solutions may or humans that CS gas is carcinogenic or be used for dermatitis and erythema."4 170 Worthington, Nee

Patients with persistent respiratory symp- should be aware of the effects of such toms should be admitted for observation; exposures and their management. Staff must humidified oxygen may provide symptomatic also ensure that they have access to appropriate

relief.'4 Aminophylline or inhaled I2 agonists personal protection equipment in order to J Accid Emerg Med: first published as 10.1136/emj.16.3.168 on 1 May 1999. Downloaded from may be necessary in the management of acute avoid becoming exposed themselves. bronchospasm in patients with pre-existing Conflict of interest: none. respiratory problems.4 Funding: none. may rarely be indicated. Exposed persons are 1 Anonymous. CS incapacitants. Guidelines for police surgeons. at risk of secondary pneumonia but there is no Advice sheets for victims. : HMSO, 1996. 2 Bhattacharya S, Hayward A. CS gas-implications for the definite evidence that prophylactic antibiotics anaesthetist. Anaesthesia 1993;48:896-7. are of any benefit.4 3 Ro YS, Lee CW. dermatitis. Int Jf Dermatol 1991;30:576-7. Pulmonary oedema and reactive pneumoni- 4 Folb P, Talmund J. Tear gas-its toxicology and suggestions tis should be managed with supportive meas- for management of its acute effects in man. S Afr Med Jf 1989;76:295. ures as above depending on its severity. It is 5 Vaca F, Myers J, Langdorf M. Delayed pulmonary edema essential to admit those individuals at risk of and bronchospasm after accidental lacrimator exposure. Am J Emerg Med 1996;14:402-5. late development of pulmonary oedema to 6 Danto BL. Medical problems and criteria regarding the use hospital for monitoring. Those at greatest risk of tear gas by police. Am J Forensic Med Pathol 1987;8:317- 22. are older people with pre-existing cardiac or 7 Anonymous. Toxicity of CS. Lancet 1971;ii:698. respiratory disease and those who have had a 8 Yih J-P. CS gas injury to the eye. BMJ 1995;311:276. 9 The truth of CS. Dispatches Channel 4, 1996. substantial exposure in confined space.4 14 10 Anonymous. "Safety" of chemical batons. Lancet 1998;352: Protection of medical staff is fundamental in 159. 11 Himsworth H, Black DAK, Crawford T, et al. Report of the managing these patients. The use of disposable enquiry into the medical and toxicological aspects of CS (ortho- rubber gloves, close fitting protective goggles, chlorobenzylidene malonitrile). II: Enquiry into the toxicological uses of CS and its use for civil purposes. London: HMSO, and garments covering the full length of arms 1971. and legs is usually sufficient.5 Contaminated 12 Gray PJ. Treating CS gas injuries to the eye. BMJ 1995;311: 871. clothing should be removed and sealed in plas- 13 Hu H, Christani D. Reactive airways dysfunction after tic bags and later rinsed several times in cool exposure to teargas. Lancet 1992;339:1535. " 14 Medical Toxicology Unit Chemical Incident Response water with conventional washing powder.' If Service (London). Crowd control agents. London: Medical clothes are washed in a washing machine a cool Toxicology Unit Chemical Incident Response Service, 1998. cycle is preferred as hot water will cause any 15 Howard H, Fine J, Epstein P, et al. Tear gas-harassing residual CS to vaporise with a risk to nearby agent or toxic ? JAMA 1989;262:660-3. 16 Punte CL, Owens EJ, Gutentag PJ, et al. Exposures to individuals.'2 ortho-chlorobenzylidene malonitrile. Arch Environ Health In patients requiring intubation all medical 1963;6:366-74. attendants should 17 Holland P, White RG. The cutaneous reactions produced by protect themselves from o-chlorobenzylidene malonitrile. Br _J Dermatol 1972;86: contamination. The anaesthetist should wear 150-4. 18 Medical Toxicology Unit Chemical Incident Response close fitting eye protection and a facemask. Service (London). Methyl isobutyl ketone. London: Medical Other procedures such as tube thoracostomy Toxicology Unit Chemical Incident Response Service, 1998. merit similar precautions. 19 Beswick FW, Holland P. Acute effects of exposure to ortho- chlorobenzylidene malonitrile. British Journal of Industrial Medicine 1972;29:298-306. Summary 20 Anonymous. Tests on CS for carcinogenicity. BMJ 1973:i: Victims exposed to CS spray, after its recent 129. http://emj.bmj.com/ 21 Park S, Giammona ST. Toxic effects of tear gas on an infant introduction as a crowd control agent by UK following prolonged exposure. Am J Dis Child 1972;123: police forces, are presenting to emergency 245-6. 22 Breakall A, Bodiwala GG. CS gas exposure in a crowded departments with increasing frequency. Clini- night club: the consequences for an accident and cal staff involved in the care of these patients emergency department. J Accid Emerg Med 1998;15:56-7. on October 4, 2021 by guest. Protected copyright.