#Gas mask filters how to#
> How to select the right class of efficiency for your particle filterįilters at least 80% of airborne particles (means that fewer than 20% of particles pass through the filter) On filtering cartridges, this information is shown on a white strip marked either P1, P2 or P3. FF stands for Filtering Facepiece, while P1, P2 and P3 refer to the class of filter efficiency. Particle filters are identified by their characteristics, which are printed directly on the mask. Particle filters provide protection against dust, fumes, micro-organisms and viruses. They are to be used exclusively with life-saving and evacuation devices. Note: Some manufacturers offer specific filters that provide protection against carbon monoxide (CO). > Some examples:Ī: xylene, styrene, phenol, white spirit, etc. Class 3: For gas concentrations of between 0.5% and 1% by volume, the largest capacity (large-capacity canister worn at waist-level)Īt an equivalent ambient concentration level, a class 3 filter will operate for longer than either a class 2 or a class 1 filter.Class 2: For gas concentrations of between 0.1% and 0.5% by volume, medium capacity (cartridge) – e.g.Class 1: For gas concentrations of less than 0.1% by volume, the lowest capacity (filters for half masks) – e.g.: A1.If the filter is designed to protect against several families of gas simultaneously, we call it a combined filter: it is designated by the juxtaposition of a letter and the corresponding colour strips (page 108 of the catalogue).ĪB = Filters organic gases/vapours and inorganic gases/vapoursīK = Filters inorganic vapours, ammonia and ammonia derivatives > How to select the right class of efficiency for your gas filterĪs for aerosol filters, there are three classes of protective filters based on their capacity (in other words, the best balance between volume and effectiveness of the absorbent material):
> How are the various types of gas filter defined?Ī specific filter for a given gas or family of gases or vapours is indicated through marking consisting of a letter and a strip of a certain colour. They are described according to 2 criteria: filter type and class. They usually consist of a bed of activated carbon.
Gas filters provide protection against vapours, chemical substances and toxic gases.
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