Effects of incapacitant spray deployed in the restraint and arrest of detainees in the Metropolitan Police Service area, London, UK: a prospective study.

PURPOSE: In the United Kingdom (UK) police restraint and control of detainees is undertaken by assorted means. Two types of incapacitant spray (IS) are approved by the UK Home Office for use: CS (o-chlorobenzylidine malononitrile, dissolved in an organic solvent--methyl iso-butyl ketone and pelargonic acid vanillyamide (PAVA). The aim of this study was to document the effects of incapacitant sprays, by symptom assessment and medical examination, within a few hours of deployment. METHODS: A detailed proforma was produced to explore the nature of the arrest, the nature of exposure to the incapacitant spray, the type of incapacitant spray, the symptoms experienced and the medical findings. RESULTS: 99 proformas were completed. 74 % were completed by detainees and 26 % were completed by police officers. 88 % were exposed to CS spray, the remainder to PAVA spray. The mean time of assessment after exposure was 2.8 ± 2.33 h (mean ± SD). The most frequent sites of IS contact were the face and scalp (n = 78), and exposure to the left and right eyes (n = 32). The most common symptoms were: painful eyes (n = 68); red eyes (n = 58); runny nose (n = 59); lacrimation (n = 55); nasal discomfort (n = 52); skin irritation (n = 49); and skin burning (n = 45). The most common medical findings were: conjunctival erythema (n = 34); skin erythema (n = 21); and rhinorrhea (n = 20). CONCLUSIONS: Symptoms and signs of exposure to IS lasted longer than was expected (a mean of 2.8 h). Approximately 30 % of those exposed had ocular effects and 20 % had skin effects. The findings of this study will enable the guidelines on the expected effects and duration of symptoms resulting from exposure to incapacitant sprays to be reviewed and suggestions for their management to be refined.

Evaluation of CS (o-chlorobenzylidene malononitrile) concentrations during U.S. Army mask confidence training.

All soldiers in the U.S. Army are required to complete mask confidence training with o-chlorobenzylidene malononitrile (CS). To instill confidence in the protective capability of the military protective mask, CS is thermally dispersed in a room where soldiers wearing military protective masks are required to conduct various physical exercises, break the seal of their mask, speak, and remove their mask. Soldiers immediately feel the irritating effects of CS when the seal of the mask is broken, which reinforces the mask's ability to shield the soldier from airborne chemical hazards. In the study described in this article, the authors examined the CS concentration inside a mask confidence chamber operated in accordance with U.S. Army training guidelines. The daily average CS concentrations ranged from 2.33-3.29 mg/m3 and exceeded the threshold limit value ceiling, the recommended exposure limit ceiling, and the concentration deemed immediately dangerous to life and health. The minimum and maximum CS concentration used during mask confidence training should be evaluated.

Acute laryngeal and bronchial obstruction after CS (o-chlorobenzylidenemalononitrile) gas inhalation.

CS gas (o-chlorobenzylidenemalononitrile) is one of the most commonly used riot agents. It can create excessive tearing, conjunctivitis, uncontrolled blinking (blepharospasm) and a sensation of burning and pain at initial exposure. Pulmonary edema (ARDS) and/or diffuse airway lesions on human would be lethal after CS inhalation. We report a case with acute laryngeal and bronchial obstruction due to vocal cord edema and extensive crusting at glottic level, trachea and bronchi. The CS gas was sprayed in a 6 x 6 m(2) closed room, and she was exposed to increased concentration of the gas for 10 s. Surprisingly, her initial symptoms were raised 21 days after CS spray exposure.

The pathology of lethal exposure to the Riot Control Agents: towards a forensics-based methodology for determining misuse.

The aim of this is to review deaths associated with the use of Riot Control Agents (RCAs) and to assess how the presenting pathologies is such cases may better inform cause of death conclusions upon autopsy. We also sought to present which additional steps should be added to the Minnesota protocol and the European harmonization of medico-legal autopsy rules in suspected cases of deaths associated with the use of RCAs. We included 10 lethal cases in our study. In three cases, RCAs were found to be the sole cause of death, in three cases RCAs were ruled a secondary cause of death due asphyxia or asthma subsequent to exposure to RCAs and in four cases RCAs were contributory factors to death. In three cases the responsible agents were identified as Chloroacetophenone (CN), Chlorobenzylidene malononitrile (CS) and Oleoresin capsicum (OC) and in the remaining 7 cases, the agent was OC alone. As there are no specific findings in suspected cases of death associated with RCA use, establishing cause of death and whether RCAs are the sole cause or only a contributory factor will be based on the elimination of other possible causes of death. For this reason, a specifically structured autopsy is essential. This specifically structured autopsy should contain basic principles of the Minnesota Protocol and the European harmonization of medico-legal autopsy rules with the following additional steps taken: examination of clothing, eyes, and skin; examination of pharyngeal, tracheobronchial, and eusophegeal mucosas; and a thorough recording of the steps taken by the party conducting the arrest, including other possible causes of in-custody death, as well as a detailed medical history of the deceased.

Medical hazards of the tear gas CS. A case of persistent, multisystem, hypersensitivity reaction and review of the literature.

A 30-year-old incarcerated man was sprayed with the "tear gas" ortho-chlorobenzylidene malononitrile (CS). He was hospitalized 8 days later with erythroderma, wheezing, pneumonitis with hypoxemia, hepatitis with jaundice, and hypereosinophilia. During the subsequent months he continued to suffer from generalized dermatitis, recurrent cough and wheezing consistent with reactive airways dysfunction syndrome, and eosinophilia. These abnormalities responded to brief courses of systemic corticosteroid but recurred off therapy. The dermatitis resolved gradually over 6-7 months, but the patient still had asthma-like symptoms a year following exposure. Patch testing confirmed sensitization to CS. The mechanism of the patient's prolonged reaction is unknown but may involve cell-mediated hypersensitivity, perhaps to adducts of CS (or a metabolite) and tissue proteins. This is the first documented case in which CS apparently caused a severe, multisystem illness by hypersensitivity rather than direct tissue toxicity. Both the ethics and safety of CS use remain controversial, in part because of the difficulty documenting sporadic injuries received in the field, and also because the charged circumstances surrounding CS use may lead to both underreporting and exaggerated claims of medical harm. The medical literature on CS focuses mainly on its immediate irritant effects and on transient dermal and ocular injuries, with only 2 prior case reports of acute lung injury related to CS exposure. Given the paucity of documented lasting effects despite its widespread use for more than 3 decades, CS appears to be safe when deployed (outdoors) in a controlled manner, but it can cause important injuries if misused or if applied to a sensitized individual.

Health and safety in policing: lessons from the regulation of CS sprays in the UK.

Recent years have seen the introduction of a wide range of weapons for police forces around the world intended to minimise injuries incurred in officer-public encounters. In 1996, police forces in England and Wales began trials of CS incapacitant sprays. This article reviews the claims and counterclaims surrounding the medical implications of the sprays with a view to asking how the uncertainties associated with them have been handled in the regulation process. This analysis casts considerable doubt on the robustness of the precautions taken and demonstrates a continuing failure for relevant government agencies to respond and learn from problems identified. Drawing on wider literature regarding the health implications of risky technologies, it further asks what policy lessons the case of the CS sprays holds for the regulation of weaponry at an international level.

Acute mass burns caused by o-chlorobenzylidene malononitrile (CS) tear gas.

The use of tear gas in controlling riots has been an accepted practice in many countries for the past four decades. In a recent event, a large quantity of tear-gas canisters were used during a situation of unrest in a Hong Kong Refugees' Detention Centre. We report 96 cases of acute burn injury as an unpredicted side effect of o-chlorobenzylidene malononitrile (CS) tear gas. There were 47 females and 49 males with an age ranging between < 1 to 51 years. These burns were categorized as minor burns, with the total body surface area (TBSA) ranging from 1 to 8 per cent with mean percentage of 3. Most of the patients sustained superficial or partial-skin thickness injuries. Only two patients were admitted to the Prince of Wales Hospital Burns Centre because of deeper burns; debridement and skin grafting was required in one of them. The mechanism of burn injury was due to the flame generated from the grenade explosion, direct contact between the hot canister and the victim's skin, and the effect of the chemical powder inside the canisters when it splashed onto the victim's body. We suggest that the noxious transient effects of tear gas are underestimated, furthermore varying cutaneous effects and deep burns may result from its uncontrolled use during riots. There is a continuing need to reassess the potential toxic effects of CS tear gas as a riot control agent and to debate whether its future use can be condoned under any circumstances.

Acute effects of the potent lacrimator o-chlorobenzylidene malononitrile (CS) tear gas.

1. The use of tear gas to control civil unrest is accepted practice by government authorities worldwide. It is rarely used in Hong Kong but during a recent riot at a Vietnamese detention centre large quantities were used and this was cause for some concern. 2. All patients presenting to the British Red Cross Clinic after the incident were seen by one of the authors. To establish if exposure to tear gas had serious effects on the health of the detainees, the case records of the 184 patients with symptoms consistent with CS exposure were reviewed 2 months later. 3. The most common complaints were burns (52%), cough (38%), headache (29%), shortness of breath (21%), chest pain (19%), sore throat (15%) and fever (13%). However, the only common findings on examination by a physician were burns (52%) and an inflamed throat (27%). All burns could be categorised as "minor' according to the American Burns Association classification and all were consistent with CS gas exposure. 4. Some patients complained of other symptoms that had not been previously reported in the literature, such as haemoptysis (8%) and haematemesis (4%), but these were only confirmed in one patient. 5. The majority of patients had recovered within 2 weeks of exposure although one asthmatic patient complained of shortness of breath lasting for 33 days and a sore throat lasting for 38 days after the incident. She had abnormally low peak expiratory flow readings, but had a clinical history of asthma. 6. No serious sequelae were encountered, but the incidence of burns in these patients was higher than would be expected from a review of the literature. However, very little data on the effects of tear gas in a riot situation has been published. There have been reports of high concentrations of CS gas causing reactive airways dysfunction but this was not seen in our group of patients.

Short-term and long-term physical effects of exposure to CS spray.

CS gas (2-chlorobenzylidene malonitrile) is widely used in an incapacitant spray that causes intense lacrimation, blepharospasm and burning sensations in the throat and nose. Questions have been raised about its safety. We obtained information on short-term and long-term symptoms, and performed ear, nose and throat examinations and respirometry at 8-10 months, in 34 young adults who had been exposed to CS spray in a confined space during a confrontation with police. The group was subdivided into those who had been sprayed directly on the face (n=10) and those exposed indirectly. At one hour, all but 2 individuals still had symptoms; respiratory and oral symptoms were significantly more prevalent in the directly exposed group. At one month, only oral symptoms were significantly more prevalent. At 8-10 months, symptoms were still reported but there were no differences between the groups and clinical examinations revealed no specific abnormalities. There was no convincing evidence of long-term physical sequelae from exposure to CS spray.

Acute pulmonary effects from o-chlorobenzylidenemalonitrile "tear gas": a unique exposure outcome unmasked by strenuous exercise after a military training event.

o-Chlorobenzylidenemalonitrile, more commonly called CS, is grouped with several other irritant agents referred to as "tear gas." It is a riot-control agent used frequently in military settings to test the ability and speed of personnel in donning their military gas masks. When personnel are exposed to CS without proper personal protective equipment, it has potent irritant effects. We report a unique cluster of hospitalizations of nine U.S. Marines who developed a transient pulmonary syndrome. All nine patients had symptoms of cough and shortness of breath. Five of the nine presented with hemoptysis, and four presented with hypoxia. Symptoms were associated with strenuous physical exercise from 36 to 84 hours after heavy exposure of CS in a field training setting. Four of the nine Marines required intensive care observation as a result of profound hypoxia. All signs and symptoms resolved within 72 hours of hospital admission. One week after CS exposure, all nine Marines demonstrated normal lung function during spirometry before and after exercise challenge using cycle ergometry.

Cutaneous burns from CS incapacitant spray.

A case of a superficial burn following exposure to CS incapacitant spray is reported. This is followed by a summary of the properties and effects of CS and the other agents which occur in the incapacitant spray. CS is relatively safe, but it does have unwanted effects, especially on skin exposure. Possible contributing factors to the production of a skin burn are discussed.

Long-term psychiatric morbidity in the aftermath of CS spray trauma.

The physical effects of CS spray are well documented. However, less is known about the impact of its use by the police on the psychological health of those exposed. In this study we explored the psychiatric morbidity of a group of 30 individuals who experienced the same trauma, a significant part of which was exposure to CS spray. Just over a quarter suffered post-traumatic stress disorder. It is proposed that more attention needs to be paid to the psychological effects of the use of CS spray by the police. Consistent with other studies, a past psychiatric history and a more external locus of control was associated with post-traumatic morbidity. The latter finding may have implications for psychological interventions after exposure to trauma.

Personal aerosol protection devices: caring for victims of exposure.

The increased incidence of violence in our society has led to a concern for personal safety. For self-protection, many individuals are turning to personal aerosol protection devices (PAPDs), which are readily accessible to the general public. The greater use and misuse of these noxious chemicals has led to an increase in injuries associated with exposure. Health care providers need to be aware of the modes of action of PAPDs, the presenting exposure symptoms, first aid measures, and decontamination procedures of the environment and the victim's belongings. This article provides a thorough discussion of PAPDs and will assist the clinician in delivering primary care and health education to victims of PAPD exposures.

O-chlorobenzylidene malononitrile (CS riot control agent) associated acute respiratory illnesses in a U.S. Army Basic Combat Training cohort.

Acute respiratory illnesses (ARIs) are among the leading causes for hospital visits in U.S. military training populations and historically peak during U.S. Army Basic Combat Training (BCT) following mandatory exposure to the riot control agent o-chlorobenzylidene malononitrile (CS). This observational prospective cohort studied the association between CS exposures and ARI-related health outcomes in 6,723 U.S. Army recruits attending BCT at Fort Jackson, South Carolina from August 1 to September 25, 2012 by capturing and linking the incidence of ARI before and after the mask confidence chamber to CS exposure data. Recruits had a significantly higher risk (risk ratio = 2.44; 95% confidence interval = 1.74, 3.43) of being diagnosed with ARI following exposure to CS compared to the period of training preceding exposure, and incidence of ARI after CS exposure was dependent on the CS exposure concentration (p = 0.03). There was a significant pre-/postexposure ARI difference across all CS concentration levels (p < 0.01), however, no significant differences were detected among these rate ratios (p = 0.72). As CS exposure is positively associated with ARI health outcomes in this population, interventions designed to reduce respiratory exposures could result in decreased hospital burden and lost training time in the U.S. Army BCT population.