Law enforcement throughout the world is increasingly responding to popular protests with crowd-control weapons (CCWs), also known as “less-lethal” weapons. The proliferation of CCWs without adequate regulation, training, monitoring, and/or accountability has led to the widespread and routine use or misuse of these weapons, resulting in injury, disability, and death. For decades, PHR has documented the severe health harms these weapons can cause, and shared resources to help prepare the public for encounters with law enforcement.
Health Impact of Crowd-Control Weapons
Crowd-control weapons can cause serious injury, disability, and even death. These fact sheets describe the health impact of acoustic weapons, blunt force weapons, directed energy devices, rubber bullets (and other kinetic impact projectiles), stun grenades (and other disorientation devices), tear gas (and other chemical irritants), and water cannons. They also outline when and how these weapons can legally be used.
Fact Sheets on Commonly Used Crowd-Control Weapons
- Acoustic Weapons
- Blunt Force Weapons
- Chemical Irritants (tear gas)
- Chemical Obscurants
- Directed Energy devices
- Disorientation Devices (stun grenades)
- Kinetic Impact projectiles (rubber bullets)
- Powder Blast Dispersion
- Scattershot Projectiles
- Water Cannons
Guidance for Protesters
- Preparing for, Protecting Against, and Treating Tear Gas and Other Chemical Irritant Exposure: A Protestor’s Guide
- Crowd-Control Weapons and Social Protest in the United States
Our Work
After the South Korean government used more than 350,000 canisters of tear gas against demonstrators in 1987, PHR organized an investigation that concluded Seoul’s indiscriminate use of massive amounts of tear gas was clearly excessive use of force, effectively changing the perception of tear gas as a harmless crowd-control tactic. Since then, PHR has conducted numerous investigations into governments’ excessive and indiscriminate use CCWs and other forms of excessive force, including in Bahrain, Georgia, Israel and the occupied Palestinian territories, Kashmir, Panama, Thailand, Türkiye, and Sudan.
In 2023, PHR and the International Network of Civil Liberties Organizations published Lethal in Disguise 2, an update to the original groundbreaking 2016 report, documenting the misuse and abuse of CCWs, the detrimental health effects that these weapons can have, and the impact of their use on freedom of assembly and expression. With our partners, PHR advocates for international standards and guidelines for CCWs in order to prevent injury, disability, and death.
PHR documents the use and misuse of crowd-control weapons by law enforcement in the United States. Our 2026 interactive visual investigation “Charting the Crackdown” mapped violence across the country during the 2025-2026 protests against U.S. immigration enforcement, in partnership with the Human Rights Center at UC Berkeley. In our investigation “Tools of Repression” PHR experts exposed the increasing use of three lesser-known crowd-control weapons being deployed in U.S. cities. PHR has documented the serious injuries inflicted on people participating in the protests and medics providing assistance to protesters during the 2020 nationwide protests of the police killing of George Floyd.
