Gas mask

related topics
{acid, form, water}
{@card@, make, design}
{ship, engine, design}
{war, force, army}
{system, computer, user}
{black, white, people}
{album, band, music}
{work, book, publish}
{woman, child, man}
{land, century, early}

A gas mask is a mask put on over the face to protect the wearer from inhaling "airborne pollutants" and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Some gas masks are also respirators, though the word gas mask is often used to refer to military equipment (e.g. Field Protective Mask, etc.) (The user of the gas mask is not protected from gas that the skin can absorb.)

Airborne toxic materials may be gaseous (for example the chlorine gas used in World War I) or particulate (such as many biological agents developed for weapons such as bacteria, viruses and toxins). Many gas masks include protection from both types. During riots where tear gas or CS-gas is employed by riot police, gas masks are commonly used by police and rioters alike.

Aside from serving their functional purposes, gas masks are also used as emblems in industrial music, by graffiti taggers because the mask protects them from the graffiti canister's toxic fumes, and by Urban Explorers venturing into environments where materials such as asbestos is present.

The traditional gas mask style with two small circular eye windows originated when the only suitable material for these eye windows was glass or perspex; as glass is notoriously brittle, glass eye windows had to be kept small and thick. Later, discovery of polycarbonate allowed gas masks with a big full-face window. Some have one or two filters attached to the face piece. Some have a large filter connected to the face piece by a hose.

Contents

Principles of construction

Absorption is the process of being drawn into a (usually larger) body, or substrate, and adsorption is the process of deposition upon a surface. This can be used to remove both particulate and gaseous hazards. Although some form of reaction may take place, it is not necessary; the method may work by attractive charges, for example, if the target particles are positively charged, use a negatively charged substrate. Examples of substrates include activated carbon, and zeolites. This effect can be very simple and highly effective, for example using a damp cloth to cover the mouth and nose whilst escaping a fire. While this method can be effective at trapping particulates produced by combustion, it does not filter out harmful gases which may be toxic or which displace the oxygen required for survival.

Full article ▸

related documents
Bessemer process
Soldering iron
Agate
Stainless steel
Amber
Polytetrafluoroethylene
Shellac
Rotaxane
Wafer (electronics)
Pipette
Lustre (mineralogy)
Quartz
Microtubule
Pyrite
Tanning
Cyanoacrylate
Rutile
Calotype
Brass
Flagellum
Hygroscopy
Diamondoid
Vacuum flask
Ductility
Hematite
Protactinium
Samarium
Compounds of carbon
Perchloric acid
Forensic engineering