Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

A police officer fires tear gas at protesters after the presidential election results were announced in Kisumu, Kenya on August 15, 2022. (Photo by Baz Ratner/Reuters)

A man wears a gas mask as he holds a bouquet of flowers, following the outbreak of the novel coronavirus on Valentine’s Day in Hong Kong, China on February 14, 2020. (Photo by Tyrone Siu/Reuters)

Fans of Gimnasia de La Plata choke on tear gas during a local tournament match between Gimnasia de La Plata and Boca Juniors in La Plata, Argentina, Thursday, October 6, 2022. The match was suspended after tear gas thrown by the police outside the stadium wafted inside affecting the players as well as fans who fled to the field to avoid its effects. (Photo by Gustavo Garello/AP Photo)

A supporter of Pakistan Tehreek-e-Insaf (PTI) party gestures after tear gas was fired by the police to disperse the crowd during a protest to demand the release of former prime minister Imran Khan in Islamabad on November 26, 2024. Thousands of protestors calling for the release of Pakistan's jailed ex-prime minister Imran Khan defied roadblocks and tear gas to march to the gates of the nation's capital on November 26. (Photo by Aamir Qureshi/AFP Photo)

A woman attempts to cover a tear gas canister fired by police at a crowd in Srinagar protesting against the recent killings in Kashmir, August 17, 2016. (Photo by Cathal McNaughton/Reuters)

Riot police fire tear gas during a protest by supporters of Dilma Rousseff in Sao Paulo, Brazil August 31, 2016. (Photo by Paulo Whitaker/Reuters)

A Palestinian protester, dressed as Santa Claus, reacts after inhaling tear gas fired by Israeli troops during clashes in the West Bank city of Bethlehem December 23, 2016. (Photo by Mussa Qawasma/Reuters)