Proforce recognises that central to the selection of the correct respiratory device is the understanding of the hazard being faced. The following key points require consideration before choosing your respirator, disposable or cartridge type. What is the name of 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 then possible to determine the Time Weighted Average (TWA).
Long Term Exposure = (Concentration X Time of Exposure) / 8
Short Term Exposure = (Concentration X Time of Exposure) / 0.25
To determine the minimum required efficiency of the appropriate filter divide TWA by OES. Proforce has a range of respiratory protection solutions to ensure that all hazards faced within the workplace have a suitable product against which you can protect. 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! BS EN Standards at a glance: EN149, filtering face piece for particulates EN405, disposable half mask respirators EN140, half masks EN136, full face masks EN141, gas & vapour filters EN143, particulate filters EN405, half masks – COSHH free
