Gas masks, Unit 731, Japanese Germ Warfare Experimental Base, Harbin, Heilongjiang, China, Asia

A Britiush Gas worker wears protective gas mask prior to cutting through the gas main as part of an upgrade of piping, Ambleside, Cumbria, England, United Kingdom, Europe

A gas mask at the Muckleborough Collection, Norfolk, England, United Kingdom, Europe

Person wearing mask in smoke

Iran, Middle East, Asia, True Colour Satellite Image With Border And Mask. Satellite view of Iran (with border and mask). This image was compiled from data acquired by LANDSAT 5 & 7 satellites.

Welder.

During a training session for workers dealing with toxic chemical spills, participants in protective suits walk down the street, Detroit, Michigan, USA

A training session for workers dealing with toxic chemical spills, Detroit, Michigan, USA

Painting, mural, completely veiled people wearing breathing masks or gas masks, Berlin Wall, East Side Gallery, Berlin, Germany, Europe

Man wearing surgical gloves and mask refueling car at gas station

Man wearing surgical gloves and mask at gas station

Man wearing surgical gloves and mask at gas station

Man wearing surgical gloves and mask refueling car at gas station