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The reckless use of tear gas by Hong Kong police in confined spaces is dangerous and patently unlawful

By Dr. Howard Hu and Phelim Kine

Hong Kong police did something medically dangerous – and patently unlawful – on Sunday night, August 11.

Riot gear-clad officers who had pursued pro-democracy protesters into the Kwai Fong subway station fired multiple barrages of tear gas into the crowded, confined space.

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File photo: May James/HKFP.

By doing so, they not only subjected the surgical- and gas-mask-wearing protesters to the risks associated with tear gas, they also put untold numbers of commuters in harm’s way by subjecting them – with no prior warning – to what is essentially an attack by a chemical weapon in a tightly confined area.

Physicians for Human Rights is not alone in sounding the warning about the illegality and public safety risks of Hong Kong police misuse of tear gas. On August 13, the Office of the United Nations High Commissioner for Human Rights declared that there was “credible evidence of employing less-lethal weapons such as tear gas in ways that are prohibited by international norms and standards.”

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Police firing tear gas inside the Kwai Fong MTR station. Photo: Felix Lam/HK.Imaginaire; RTHK screenshot.

The police deployment of tear gas in the subway station put both protesters and commuters at risk of injury or even death from either the blunt trauma inflicted by the high-velocity cartridges that deliver the gas or the inhalation of the gas itself. That’s because the use of tear gas in any confined space, including a subway station, greatly increases the levels of exposure and, consequently, the quantities of gas that are typically inhaled.

While no evidence has surfaced so far that such injuries resulted from the tear gas attack on Kwai Fong subway station, all protesters and commuters without adequate protective equipment were subjected to tearing and eye pain and were at potential risk of corneal injury, respiratory distress, allergic reactions, and chemical burns.

Moreover, the risk that respiratory distress could progress to potentially fatal lung injury is accentuated in the elderly, children, and individuals with pre-existing cardiac or respiratory disease, such as asthma or emphysema.

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File photo: Holmes Chan/HKFP.

The tear gas attack on the Kwai Fong subway station was more than just a willfully reckless use of what is classified as a “non-lethal incapacitating weapon” designed to reduce the need for deployment of lethal firearms in crowd-control situations. It constituted a violation of United Nations international standards on how such weapons can and should be used.

The UN Basic Principles on the Use of Force and Firearms by Law Enforcement Officials stipulate that the use of non-lethal incapacitating weapons such as tear gas requires careful evaluation to ensure that “uninvolved persons” are not endangered by their usage, guidance ignored in the subway station attack.

The Principles also specify that police cannot plead “exceptional circumstances such as internal political instability or any other public emergency” to deviate from ensuring the safest deployment of such weapons.

The Kwai Fong tear gas attack was just the latest in a recent serious escalation in the Hong Kong police’s abuse of this indiscriminate and potentially lethal weapon to disperse protesters.

Although Hong Kong police deployed tear gas during the Umbrella Movement protests that paralyzed large swathes of the city’s business district for two months in 2014, its use has skyrocketed in recent days in an apparent desperate effort to quell intensifying protests by hundreds of thousands of protestors who have flooded Hong Kong’s streets in a tenacious display of defiance to perceived threats to Hong Kong’s rights and freedoms.

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File photo: Holmes Chan/HKFP.

Whereas in the two months of the Umbrella Movement protests Hong Kong police deployed a total of 87 tear gas rounds, they fired more than 1,000 tear gas rounds in 14 of 18 city districts between June 9 and August 4 alone. Such an escalation suggests that the police are operating under woeful ignorance or willful disregard of the rules on the safe and lawful use of tear gas in densely populated areas.

We at Physicians for Human Rights (PHR) have documented the impact of such misuse of this chemical agent for decades, including in Bahrain, Egypt, and Kenya. However, the Hong Kong police’s misuse of tear gas bears the most striking and sinister resemblance to the extreme deployment of tear gas by police in South Korea against pro-democracy protesters which PHR documented in 1987.

In that instance, South Korean police often fired tear gas cylinders directly into crowds or into enclosed spaces where people gathered. The tear gas they used – O-chlorobenzylidene malononitrile, commonly referred to as CS gas – is the same chemical formula that Hong Kong police are deploying today.

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File photo: May James/HKFP.

The injuries sustained by South Korean tear gas victims which PHR documented then – including crushing chest injuries, eye injuries resulting in blindness, and blistering skin burns from direct contact with the chemical – provide an alarming indication of the possible outcomes if Hong Kong police continue to deploy tear gas with wanton disregard for public health.

Tragically, some South Korean tear gas victims developed chronic conditions linked to exposure to tear gas, including deterioration of lung function, new onset asthma, and chronic obstructive pulmonary disease.

The scale of the South Korean police deployment of tear gas – 331,000 cannisters and grenades in a two-month period – dwarfs what we have seen in Hong Kong so far. But the similarity between what we documented in South Korea and what we are seeing in Hong Kong is alarming and requires the Hong Kong police and authorities to immediately curtail both the quantity and location of their use of tear gas to avoid such harmful impacts on Hong Kongers.

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File photo: May James/HKFP.

The Hong Kong police has for decades staked a claim as “Asia’s finest,” a regional exemplar of professional policing. The police who fired tear gas canisters into the Kwai Fong subway station should have known full well the potentially deadly consequences of their actions. Poor judgement, or worse, reckless disregard for public safety, demands consequences.

The UN Principles stipulate that “arbitrary or abusive use of force” of any kind, including deployment of tear gas, should result in criminal prosecution for police officers responsible for those actions as well as their superior officers if “they did not take all measures in their power to prevent, suppress or report such use.”

The only way to break the Hong Kong police’s dangerous reliance on tear gas is accountability and legal consequences for officers and their superiors who are deploying it in blatantly dangerous and unlawful ways. Until that happens, these kinds of attacks may well continue, with potentially tragic results.


Phelim Kine is Director of Research & Investigations at Physicians for Human Rights.

The reckless use of tear gas by Hong Kong police in confined spaces is dangerous and patently unlawful