30 lethal,90 such as when they are dispersed in confined spaces and result in high levels of exposure. Pyrotechnic projectiles containing chemical irritants may result in death if the round burns near combustible material and causes a fire. 7.3.4 If chemical irritants are deployed behind a group of violent individuals, this may prompt them to move towards law enforcement officials and agencies, thereby increasing the risk of a violent confrontation. Irritants will also affect law enforcement officials if they are not adequately protected from cross-contamination caused by the movement of the irritant cloud/particles. 7.3.5 The use of chemical irritants can temporarily cause breathing difficulties, nausea, vomiting, irritation of the respiratory tract, tear ducts and eyes, spasms, chest pains, dermatitis or allergies. In large doses, it can cause necrosis of the tissue in the respiratory tract and the digestive system, pulmonary oedema and internal bleeding.91 Repeated or prolonged exposure to chemical irritants should be avoided. Any person who has been exposed to any chemical irritant should be decontaminated as soon as possible. CIRCUMSTANCES OF POTENTIALLY UNLAWFUL USE 7.3.6 Irritant projectiles should generally not be fired at an individual. In any event, projectiles should not be fired at the head or face, owing to the risk of death or serious injury from impact trauma.92 Y. Karagama et al., “Short-Term and Long-Term Physical Effects of Exposure to CS Spray”, Journal of the Royal Society of Medicine, vol. 96, No. 4 (2003), pp. 172–74; M. Crowley, Chemical Control (Palgrave, London, 2015), p. 48. See also R.J. Haar et al., “Health impacts of chemical irritants used for crowd control: a systematic review of the injuries and deaths caused by tear gas and pepper spray”, BMC Public Health, vol. 17 (2017). 91 European Court of Human Rights, Abdullah Yaşa and others v. Turkey, Judgment, 16  July 2013, para. 30. 92 European Court of Human Rights, Ataykaya v. Turkey, Judgment, 22 July 2014, paras. 56–57. 90