SafetyDepot recognises that central to the
selection of the correct respiratory protection (face mask) is the understanding
of the hazard being faced.

The following key points require consideration before choosing your respirator,
whether disposable or re-usable cartridge type.

• What exactly is the the hazard


• In what form is the hazard encountered


• What other applicable regulations may effect selection


• What is the Occupational Exposure Standard (OES) for the hazard


• What is the airborne concentration of the hazard


• How long will worker(s) be exposed to the hazard within any given 24hr
  period

With all of this information it is possible to work out the Time Weighted
Average,

There are five forms of hazard that are commonly encountered within the
workplace, these include,

Dust - formed by the breaking down of solid materials in
general the smaller the dust particle the greater the hazard. Fibres of material
should also be treated as dusts.

Mist - Formed by processes that involve atomisation and
condensation, such as spraying, and consists of tiny liquid droplets

Fume - formed by the vaporisation of a solid material by the
application of intense heat. Extremely fine solid particles are formed as the
vapour cools and condenses

Vapour - a gaseous state formed by evaporation from
substances that are normally either solid or liquid at room temperature

Gas - an air like substance at room temperature. Gases can
travel very far very quickly.