Send to

Choose Destination
BMC Public Health. 2017 Oct 19;17(1):831. doi: 10.1186/s12889-017-4814-6.

Health impacts of chemical irritants used for crowd control: a systematic review of the injuries and deaths caused by tear gas and pepper spray.

Author information

University of California, 3136 College Avenue, Berkeley, CA, 94705, USA.
Physicians for Human Rights, 256 W 38th Street, 9th Floor, New York, NY, 10018, USA.
Emory University School of Medicine, 100 Woodruff Circle, Atlanta, GA, 30322, USA.
Division of HIV, ID and Global Medicine, Department of Medicine, University of California, 533 Parnassus, Box 1031, San Francisco, CA, 94143, USA.



Chemical irritants used in crowd control, such as tear gases and pepper sprays, are generally considered to be safe and to cause only transient pain and lacrimation. However, there are numerous reports that use and misuse of these chemicals may cause serious injuries. We aimed to review documented injuries from chemical irritants to better understand the morbidity and mortality associated with these weapons.


We conducted a systematic review using PRISMA guidelines to identify injuries, permanent disabilities, and deaths from chemical irritants worldwide between January 1, 1990 and March 15, 2015. We reviewed injuries to different body systems, injury severity, and potential risk factors for injury severity. We also assessed region, context and quality of each included article.


We identified 31 studies from 11 countries. These reported on 5131 people who suffered injuries, two of whom died and 58 of whom suffered permanent disabilities. Out of 9261 total injuries, 8.7% were severe and required professional medical management, while 17% were moderate and 74.3% were minor. Severe injuries occurred to all body systems, with the majority of injuries impacting the skin and eyes. Projectile munition trauma caused 231 projectile injuries, with 63 (27%) severe injuries, including major head injury and vision loss. Potentiating factors for more severe injury included environmental conditions, prolonged exposure time, and higher quantities of chemical agent in enclosed spaces.


Although chemical weapons may have a limited role in crowd control, our findings demonstrate that they have significant potential for misuse, leading to unnecessary morbidity and mortality. A nuanced understanding of the health impacts of chemical weapons and mitigating factors is imperative to avoiding indiscriminate use of chemical weapons and associated health consequences.


2-chlorobenzalmalonitrile (agent CS); Crowd control; Demonstrations; Less lethal weapons; Oleoresin capsicum (agent OC); Pelargonic acid vanillylamide or capsaicin II (PAVA); Pepper spray; Protests; Tear gas

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center