Gas mask

A gas mask is a mask worn on the face to protect the body from airborne pollutants and toxic materials, and also known as a respirator. The mask may cover the eyes and other vulnerable soft tissues of the face, and will always form a sealed cover over the nose and mouth.

Reaction and exchange

This principle relies upon the fact that substances that can do harm to humans are usually more reactive than air. This method of separation will use some form of generally reactive substance (for example an acid) coating or supported by some solid material. An excellent example is resins. These can be created with different groups of atoms (usually called functional groups) that exhibit different properties. Thus a resin can be tailored to a particular toxic group. When the reactive substance comes in contact with the resin, it will bond to it, removing it from the air stream. It may also exchange with a more harmless substance at this site.

Related Topics:
Acid - Resin - Atom

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There are two main difficulties with gas-mask design:

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The user may be exposed to many different types of toxic material. Miltary personel are especially prone to being exposed to a diverse range of toxic gases. However if the mask is for a particular use (such as the protection from a specific toxic material in a factory), then the design can be much simpler and the cost lower.

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The protection will wear off over time. Filters will clog up, substrates for absorption will fill up, and reactive filters will run out of reactive substance. This means that the user only has protection for so long, and then they must either replace the filter device in the mask, or use a new mask.

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