gas mask


Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Wikipedia.

gas mask,

face covering or device used to protect the wearer from injurious gases and other noxious materials by filtering and purifying inhaled air. In addition to military use (see chemical warfarechemical warfare,
employment in war of incendiaries, poison gases, and other chemical substances. Ancient armies attacking or defending fortified cities threw burning oil and fireballs. A primitive type of flamethrower was employed as early as the 5th cent. B.C.
..... Click the link for more information.
), gas masks are employed in mining, in industrial chemistry, and by firemen and rescue squads. The gas mask consists essentially of a face cover with two eyepieces and a mouthpiece that communicates with a canister containing a filter. The filter absorbs noxious gases as they pass through the canister to the mouth. The face cover also has a one-way outlet valve for exhaled air. See poison gaspoison gas,
any of various gases sometimes used in warfare or riot control because of their poisonous or corrosive nature. These gases may be roughly grouped according to the portal of entry into the body and their physiological effects.
..... Click the link for more information.
.

Gas Mask

 

a device for protecting the respiratory organs, eyes, and face of a person against toxic and radioactive substances, bacterial agents, and other harmful impurities in the air in the form of vapors, gases, or aerosols. Gas masks are classified by their method of protection as filtering masks, whose action is based on decontamination or filtration of harmful impurities from the air inspired, and oxygen masks, which completely isolate the respiratory organs from the environment (the air breathed is regenerated in the cartridge of the gas mask).

Filtration gas masks in the form of multilayered gauze bandages soaked with special solutions for protection against chlorine and phosgene appeared during World War I, but they were not effective against other toxic agents. In 1915 the Russian chemist N. D. Zelinskii invented the world’s first dry filtering gas mask with activated charcoal and a rubber mask. In 1916 this gas mask was adopted by the Russian and Allied armies. Dry gas masks soon appeared in the armies of other countries. The present-day filtering gas mask consists of a canister, a facepiece (helmet), and a carrier (pouch). As it is inspired, the contaminated air enters the canister. Aerosols are removed in the aerosol filter, and vapors and gases are removed in the layer (chemical absorber) of activated charcoal. The air decontaminated in the canister passes through the connecting tube under the facepiece of the mask. The facepiece consists of a rubber helmet-mask with goggles and a valve unit. The gas mask set includes means to prevent the goggles from steaming up (a special pencil and an antisweat film). In the winter, insulating packing is mounted on the eyepiece rings of the helmet-mask. The mask can be used for an extended period of time and weighs about 2 kg.

Isolation-type oxygen masks are used in cases where filtering masks do not provide protection, for example, where there is a deficiency of oxygen in the environment. A distinction is made between oxygen masks based on the use of chemicals and those using compressed oxygen in containers. In the first kind, air that is exhaled enters the cartridge where water vapor and carbon dioxide are absorbed and oxygen is given off; the air then passes into the breathing bag. When inspired, the air passes again from the bag through the cartridge and enters at the bottom of the facepiece. The process is repeated for each breathing cycle. This kind of gas mask can be used from one to three hours and weighs 4–4.5 kg. In the isolation-type mask based on the use of compressed oxygen, when the exhaled air enters the cartridge the carbon dioxide is removed and the air passes into the breathing bag, to which oxygen from the bottle is fed simultaneously. When inspired, the oxygen-enriched air enters at the bottom of the facepiece of the mask. This kind of mask can be used for one or two hours and weighs roughly 9 kg.

M. I. PROSTOMOLOTOV

gas mask

[′gas ‚mask]
(engineering)
A device to protect the eyes and respiratory tract from noxious gases, vapors, and aerosols, by removing contamination with a filter and a bed of adsorbent material.
References in periodicals archive ?
Gas mask distribution in Birmingham, October 1939 and, above, competitors in the Newcastle West End Police gas mask snooker handicap in aid of the British Red Cross
They've been sleeping in protective clothing and report quickly with gas masks on .
Initial M3 facepiece production problems led to the adoption of the M4 lightweight gas mask, an M2 facepiece overhauled and assembled with lightweight mask parts (filter, hose, and carrier).
Dever said every Sailor on Stennis will leave the gas mask testing area with all-new CBR equipment.
Too bad we don't keep extra gas masks for visitors," my father says, eyeing me.
During the last leg of the flight, I seriously practice the use of my gas mask for the first time.
Format:( 1; is one is an adult gas mask, but there were also special masks for children and babies.
In such cases a gas mask for 15-16 minutes will be sufficient for you," added Harris.
Crowds at a Tel Aviv distribution centre waited hours to collect gas masks yesterday.
If it stuck there the gas mask was properly sealed and safe.
A standard gas mask costs around pounds 100, but, said Mr Howell, could prove a worthy investment.
is marketing a gas mask for use by European military, civil defense, police, fire medical and emergency personnel.