The riots in Hong Kong are good news for one sector of China’s economy: tear gas manufacturers.

Chinese companies that produce tear gas and other crowd-control weapons are gearing up to meet increased demand in China and abroad. Police in Hong Kong, a semi-autonomous part of China, have repeatedly fired tear gas against protestors in the former British colony. Massive protests have swept Hong Kong this year in response to a new law that would have eased extraditions to China, as well as what Hongkongers see as Beijing’s gradual usurpation of democratic rights promised when Britain handed back the colony in 1997.

Interestingly, the tear gas used by Hong Kong police is not made in China. “Although Hong Kong – where tear gas has been extensively by police during the ongoing anti-government protests – relies on foreign suppliers, mainland China produces its own supplies along with other so-called ‘non-lethal’ weapons such as acoustic and electromagnetic equipment,” according to Hong Kong’s South China Morning Post.

The Chinese government has an appetite for tear gas. “China started producing its own tear gas in the 1990s,” said the Post. “Over the past decade, mainland riot police have reportedly used tear gas at some of the country’s most high-profile protests, including demonstrations against land seizures in Wukan village in the southern province of Guangdong in 2011 and 2016.”

That appetite for crowd suppression is growing. “In 2016, 16 companies across the country were selected by a government procurement process to supply the ministry with backpack tear gas spray,” said the Post. “This number had increased to 50 by the time of the 2018 bidding process.”

There are also reports that “made-in-China tear gas was being used against protesters during Thailand’s political unrest, the Arab spring and at anti-government demonstrations in Sudan and Venezuela,” the Post noted.

Tear gas has been used as a military weapon—the United States used it in Vietnam to flush the Viet Cong out of tunnels—though international law classifies it as a chemical weapon that is banned for combat purposes, though armies can use it for crowd control. Typically, tear gas is associated with civilian law enforcement. Global demand for tear gas has boomed in recent years as governments from France to Egypt have struggled with domestic turmoil. This is part of a global riot control equipment market that is expected to reach $13.5 billion by 2024.

But non-lethal crowd control is a particularly significant issue for China’s military. It was thirty years ago when People’s Liberation Army troops used live ammunition to kill thousands of people during the infamous 1989 Tiananmen Square protests in Beijing. Some Chinese soldiers balked at shooting civilians, while their commanders complained that lack of non-lethal weapons forced them to use live ammunition (though tear gas was used at Tiananmen Square).

China has made no secret that the protests continue or get out of hand, the army might intervene in Hong Kong. “We are determined to protect national sovereignty, security, stability and the prosperity of Hong Kong,” Chen Daoxiang, commander of the PLA garrison in Hong Kong, warned last month. An ominous Youtube video showed Chinese troops clad in riot gear practicing riot control, including firing tear gas. Those scenes were interspersed with footage of soldiers shooting rifles as they stormed buildings.

A military crackdown in Hong Kong would generate a tremendous international backlash, and possibly domestic discontent as well. A robust supply of tear gas would give the Chinese army a less bloody option than bullets.

Michael Peck is a contributing writer for the National Interest. He can be found on Twitter and Facebook.

Image: Reuters.