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 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)

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)

Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)

Local men help a wounded woman after a mortar attack by the Ukrainian army of the center of Donetsk, Ukraine, 14 August 2014. Reports state that ten local people where wounded and one killed after the mortar attack. (Photo by Sergei Ilnitsky/EPA)

Ballet dancer and performer Ashlee Montague of New York wears a gas mask while she dances in Times Square as the coronavirus disease (COVID-19) outbreak continued in Manhattan, New York City, U.S., March 18, 2020. (Photo by Andrew Kelly/Reuters)

A police officer fires his tear gas launcher during a clash with student protesters in Surabaya, East Java, Indonesia, Thursday, October 8, 2020. Thousands of enraged students and workers staged rallies across Indonesia on Thursday in opposition to the new law they say will cripple labor rights and harm the environment. (Photo by Trisnadi/AP Photo)

Turkish police detained dozens of demonstrators participating in an LGBT pride march in Istanbul, Turkey on June 26, 2021. Police fired tear gas, rubber bullets and blocked attempts by protesters to gather in large numbers after a government decision to ban pride events in recent years. (Photo by Diego Cupolo/NurPhoto/Rex Features/Shutterstock)