Why police use of tear gas should be banned

Tear gas is illegal in warfare under the Chemical Weapons Convention, and should be banned for use against civilians under international human rights law, write Vincent Wong, Natasha Williams and Maija Fiorante.

Illegal in warfare, tear gas is widely used by law enforcement authorities against civilians

People in Montreal flee as police disperse tear gas during a May 31 demonstration calling for justice in the death of George Floyd and victims of police brutality. (Graham Hughes/Canadian Press)

This column is an opinion by Vincent Wong, Natasha Williams and Maija Fiorante. Wong was a research associate at the International Human Rights Program at the University of Toronto Faculty of Law, where Williams and Fiorante are second-year students. The three co-authored 'The Problematic Legality of Tear Gas in International Human Rights Law.' For more information about CBC's Opinion section, please see the FAQ.

Videos of people emerging from clouds of smoke, coughing and clutching their chests, have become a common scene from protests worldwide, from Black Lives Matter demonstrations in U.S. cities, to anti-government protests in Belarus, Hong Kong and Lebanon. As the use of tear gas has become ubiquitous in policing protests, so too have questions about its legality and the harm it causes.

Despite its widespread use, tear gas is a dangerous and indiscriminate chemical agent that is chronically abused by law enforcement to suppress those exercising their freedoms of expression and assembly. Tear gas is already illegal in warfare under the Chemical Weapons Convention, and should be banned under international human rights law. 

Tear gas is not a low-risk weapon. The chemical agent does not distinguish between the young and the elderly, the healthy and the sick, the peaceful and the violent.

It poses particular health risks for vulnerable groups, such as children and those with pre-existing conditions.

These problems are only intensified when law enforcement misuses tear gas, as they often do, deploying it in large quantities, in confined or densely populated spaces, and against peaceful demonstrators. Prolonged exposure, or exposure to large quantities, can cause severe injuries such as blindness, chemical burns and even respiratory failure leading to death.

A protester rinses the eyes of another with water after police in Washington fired tear gas during a protest against the death of George Floyd near the White House on May 31. (Roberto Schmidt/AFP/Getty Images)

A recent surge in its use against protestors, coupled with the devastation of a global pandemic, exacerbates the risk of harm. There's concern among medical professionals that the use of tear gas can increase the risk of developing and spreading respiratory illnesses, including COVID-19, adding to the dangers of the agent.

Tear gas canisters themselves are also a threat, and have caused deaths when launched directly at protestors. It is time for the dangers of this weapon to be fully recognized.

In 1997, the Chemical Weapons Convention entered into force, with states agreeing that tear gas should not be acceptable during war, where far greater leeway is given to the use of deadly force. The Convention received almost unanimous support, with 193 countries having ratified it. However, the agreement was negotiated as to exempt the use of the agents for riot control purposes, allowing law enforcement agencies to use tear gas on civilians.

One reason for the ban of tear gas in warfare is that these agents do not distinguish between combatants and noncombatants.

The indiscriminate nature of the weapon also results in similar problems outside of war. Tear gas causes harm regardless of whether someone is a rally-goer or a bystander.

People in Washington who had gathered to protest the death of George Floyd run from tear gas used by police to clear the street near the White House on June 1. (The Associated Press)

Although tear gas is exempted from the Chemical Weapons Convention, international guidance on the use of force for law enforcement has existed for decades.

The UN recently released a new set of guidelines focusing specifically on what it terms "less-lethal weapons." These guidelines state that tear gas "should be targeted at groups of violent individuals unless it is lawful in the circumstances to disperse the entire assembly. Such use should accord due consideration to the impact on other non-violent participants or bystanders ... due attention should be paid to the potential for panic in a crowd, including the risk of a stampede."

Under international law, the use of any force by law enforcement must be necessary and proportionate to the situation. However, as a recent Amnesty International investigation shows, tear gas is seldom used in accordance with these principles.

Instead, it has become the weapon of choice for policing assemblies and demonstrations, and is often used to disperse largely peaceful crowds, preventing people from exercising their fundamental freedoms of assembly, association and expression.

A demonstrator suffers the effects of tear gas exposure after police deployed it June 13 in Atlanta, to clear a protest near the restaurant where Rayshard Brooks was fatally shot by Atlanta police. (Ben Gray/Atlanta Journal-Constitution via The Associated Press)

And it is projected that the riot-control market will experience at least a 4 per cent compounded annual growth rate over the next five years, as demand for these types of weapons by local law enforcement continues to grow.

Misuse of tear gas can constitute cruel and inhuman treatment, and in the worst cases, can violate the right to life. More UN guidance has clearly not resulted in more humane and proportionate use.

The best way to address the dangers of tear gas is to ban it under international human rights law altogether.

Medical volunteers help a man as police fire tear gas during a protest against Beijing's national security legislation in Hong Kong on May 24. Police fired volleys of tear gas in a popular shopping district as hundreds took to the streets to march against China's proposed tough national security legislation for the city. (Vincent Yu/The Associated Press)

The UN, international rights groups, domestic governments, and international courts have already signalled a growing movement toward restricting the use and trade of tear gas.

Both the U.K. and U.S. banned the export of tear gas to Hong Kong in response to misuse by the Hong Kong Police Force last year, and several U.S. cities have implemented temporary bans on its use as well.

In Canada, NDP MP Matthew Green has sponsored a House of Commons petition calling for a nationwide ban on the use of tear gas in Canada after police in Montreal used the agent against Black Lives Matter protestors this summer.

By removing access to tear gas, police and lawmakers will have to reckon with techniques to de-escalate protests and peaceful gatherings, encourage non-violent strategies and political solutions, and give priority to freedom of expression and assembly — primary considerations in a free and democratic society. In turn, this will encourage states to engage in a culture shift that truly respects and fulfills their human rights obligations, and ultimately better protects the fundamental rights of individuals.