27 which is incorporated into liquid and then pressurized to turn it into an aerosol. Sprays come in the form of jets or “fogger” variants, with jets being more discriminating. 7.2.2 Hand-held chemical irritants are used to incapacitate or dissuade a violent assailant or to help effect the lawful arrest of a suspect who is resisting violently.80 They are designed to be sprayed in the face of a person from a distance of up to several metres, delivering the active chemical to the eyes, nose and mouth, causing irritation to the eyes, upper respiratory tract and skin.81 Hand-held sprays come in different sizes, and disperse varying quantities with each use. CIRCUMSTANCES OF POTENTIALLY LAWFUL USE 7.2.3 A chemical irritant should be used only where sufficient toxicological information is available to confirm that it will not cause any unwarranted health problems and when its delivery against a target is accurate. Chemical irritants should only be deployed where a law enforcement official has reason to believe there is an imminent threat of injury. SPECIFIC RISKS 7.2.4 When chemical irritants are used appropriately, their effects are normally transient, lasting up to approximately three hours.82 Exposure to fresh air and treating the eyes with cool water83 typically remedies the effects within one or two hours. Some people, however, have exceptionally severe reactions to irritant spray. Restraining a suspect by placing them in the prone position (i.e., where the person is lying flat with the chest down and back up) should Omega Foundation, “Crowd Control Technologies: An Appraisal of Technologies for Political Control”, 2000. 81 J. McGorrigan and J.J. Payne-James, “Irritant Sprays: Clinical Effects and Management”, Faculty of Forensic and Legal Medicine, United Kingdom, 2017 (available at http://bit.ly/2R4mfDE). 82 J.J. Payne-James, G. Smith, E. Rivers, S. O’Rourke, M. Stark and N. Sutcliffe, “Effects of incapacitant spray deployed in the restraint and arrest of detainees in the Metropolitan Police Service area, London, UK: a prospective study”, Forensic Science Medicine and Pathology, vol. 10, No. 1 (March 2014), pp. 62–68. 83 Hot water will reactivate the irritant. 80