The earliest known gas masks were made in Iraq in the 9th century to protect people working in polluted wells. In the 17th century, plague doctors wore bird-shaped masks filled with herbs to protect them from getting sick. But it wasn't until the 18th century that Jean-François Pilatre de Rosie invented the first breathing apparatus. Primitive respirators were widely used by miners in the 18th century.
In the middle of the 19th century, the construction of gas masks, which we already know, was patented. It is designed to filter dust from the air inhaled by the user. In 1914, Gareth Morgan invented a breathing apparatus that used a hood and a hose hung from the floor to prevent inhalation of smoke. Today's gas masks hood as featured on Gas Mask Pro is more of an upgraded version with a revised filter and blower system.
A special air supply was later added to these masks, and shortly thereafter, in 1915, Nikolai Zelinsky invented the first gas mask to use activated carbon to filter toxic gases and aided military efforts by introducing chemical warfare agents. In 1943 the British Army developed a more modern gas mask.
These masks are lighter, less bulky, and more compliant to the face than those used during World War I. This allows for the use of separate, interchangeable filters. It also provides protection against emerging threats from nuclear and biological warfare pollutants. This became the standard during World War II.