Management of the effects of exposure to tear gas

CS Gas – Secondary effects on healthcare professionals

20 February 2010

Dear Sir

We read with interest the article by Carron et al regarding the effects of exposure to tear gas(1). We agree that with their comments relating to the multiple effects of these chemical irritants especially chlorobenzylidene-malononitrile (CS gas). We encountered a case whereby a 27yr old gentleman was sprayed with CS gas by police following a dispute with his girlfriend. He sustained mixed thickness burns to his face, trunk, upper arms and was managed by isolation in a cubicle room. According to his medical records, he had experienced similar sequelae 3yrs earlier when he allegedly was fleeing from police and was sprayed with CS gas. He had a similar injury pattern affecting his face, trunk and upper arms and he was eventually discharged with little scarring to his face.

With reports of sensitisation to the effects of CS gas(2), our initial suspicions of sensitisation of this patient were unfounded. However, whilst we have no control over these often frequent offenders who are sprayed with CS gas, we were concerned regarding the potential secondary effects on healthcare professionals who come into contact with these individuals.

As highlighted by Carron et al., the secondary effects of exposure to irritant substances like chlorobenzylidene-malononitrile is real(1). In Britain, the use of tear gas for crowd control is uncommon, but the use of CS gas is more apparent. Police are advised on the decontamination of subjects exposed to CS gas and are warned of the risk to officers who are ‘inadvertently exposed to, or cross-contaminated’ with CS gas(3). However, guidance on the management of the secondary effects is absent. The secondary effects of CS gas exposure can be significant and we feel it is an important consideration which should form part of guidance for police, with increased awareness for healthcare professionals.

Davey et al. reported difficulty reintubating a patient after suffering from laryngospasm from initial extubation post surgery(4). The patient had been sprayed with CS spray 10hrs earlier, prior to surgery. As the patient emerged from his anaesthetic, he coughed repeatedly, at which point the anaesthetist experienced progressive burning sensation over her face and eyes. The senior anaesthetist who was called to help also suffered from ‘excessive lacrimation and facial burning sensation’. Although no harm came to patient or either anaesthetist, such an occurrence could have compromised the patient’s care including his life. Hankin et al. reported secondary exposure to CS gas over a prolonged period of time due to the lingering effects of CS gas in a confined space(5). Twenty-one staff workers across Scotland came into contact with the CS gas which was initially sprayed in the back of a delivery vehicle to detect unauthorised stowaways. Staff from 16 different stores complained of the irritant effects of CS gas as the vehicle travelled across the different stores. This illustrates the extent and longevity that CS gas can have in being able to cause effects over such a long period of time after initial use. In the US, where the use of CS gas is more ubiquitous, secondary effects have been reported on a more regular basis, directly affecting accident and emergency staff(6). A case report of 3 emergency staff who had been exposed to CS was reported in 2005(7). They suffered from respiratory and eye irritation effects whilst trying to treat a patient.

Further to this, people can be sensitised to the effects of CS gas after repeated exposure. Varma et al. reported apparent sensitisation of their patient after being sprayed with CS gas on 2 separate occasions – the second occasion requiring intravenous antibiotics and systemic steroids(2). Hill et al. reported a case of multisystem hypersensitivity reaction to CS gas requiring ICU admission for several months(8). After the patient recovered and was discharged, patch testing was performed and it was discovered that the patient had a ‘marked sensitization to CS.’

In view of the potential secondary effects of irritant substances, there should be guidance for healthcare professionals to help reduce chances of secondary exposure. We are aware that CS gas lingers in hair and skin and therefore decontamination must form part of patient management. Our suggested algorithm is as follows:

230983(Figure 1)

In conclusion, secondary exposure to CS gas can pose significant risk to healthcare professionals, which in turn can compromise patient care. We must take appropriate precautions in protecting themselves from exposure from affected patient(s) thereby allowing us to treat patients successfully.


1. Carron PN, Yersin B. Management of the effects of Tear gas exposure. BMJ. 2009 Jun 19;338:b2283

2. Varma S, Holt PJ. Severe cutaneous reaction to CS gas. Clin Exp Dermatol. 2001 May;26(3): 248-50.

3. Incapacitant Spray: Guidance on the Use of Incapacitant Spray, Association of Chief Police Officer of England, Wales & Northern Ireland; May 2009.

4. Davey A, Moppett IK. Postoperative complications after CS spray exposure. Anaesthesia 59 (2004), pp1219-20

5. Hankin SM, Ramsay CN. Investigation of accidental secondary exposure to CS agent. Clin Toxicol (Phila) 45 (4) (2007), pp 409-11.

6. Horton DK, Berkowitz Z, Kaye WE. Secondary contamination of emergency department personnel from hazardous materials events, 1995-2001. Am J Emerg Med. 2003;21:28-33.

7. Horton DK, Burgess P, Rossiter S, Kaye W. Secondary contamination of emergency department personnel from o-chlorobenzylidene malononitrile exposure. Ann Emerg Med 2005; 45:655-8

8. Hill AR, Silverberg NB, Mayorga D, Baldwin HE. Medical hazards of the tear gas CS. A case of persistent, multisystem, hypersensitivity reaction and review of the literature. Medicine (Baltimore). 2000 Jul;79(4):234-40.

Competing interests: None declared

Patient consent obtained.

Competing interests: None declared

Nakul Kain, Clinical Fellow in Burns and Plastic Surgery

Anuj Mishra, M Ian James

Whiston Hospital, Liverpool, L355DR

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