Filtering half masks

Filtering devices Half or quarter mask and filter Filtering half-mask without inhalation valves Valved filtering half masks Filtering half masks Full face mask and filter Power assisted filtering device with full, half or quarter masks Power filtering device with helmet or hood 4-40... 

Filtering half masks to protect against particles. Superseded BS 6016 1980... 

Quarter mask (EN 140) Filtering half mask (EN 149) Respiratory protective hood ... 

Fig. 6.29 Half masks and filtering half masks, (a) Half-mask with a connector for a screw thread filter (b) half-mask with an inserted filter (c) filtering halfmask.

Filtering half masks consist either wholly or partly of filtering material. Otherwise, the filtering material is combined inseparably with the half mask. This type of protective device is standardized according to EN 149 [6-68]. Figure 6.29 shows a model of a filtering half mask and various other types. 

Because of the excellent wearing comfort and the low prices, particle-filtering half masks are preferred for everyday working situations. In analogy to particle filters for half masks, they are subdivided into 3 classes, using the code FFP 1, 2, or 3 according to EN 149 [6-68]. Particle-filtering half masks are available on the market... 

Fig. 6.33 Particle-filtering half masks, (a) Mouth protection against coarse dusts (b) protection level FFPl without exhalation valve (c) protection level FFPl with exhalation valve (d) protection level FFP3 with an exhalation valve (e) FFP3 with an exhalation valve.

Table 6.22 Applications of particle filters in half, quarter, and particle-filtering half masks.

Filtering half masks are designed as typical single-use objects, which caimot be cleaned. For hygienic reasons they must not used by more than one person. The frames of full, half, or quarter masks must be cleaned and - if necessary - disinfected. 

Gas-filtering half masks, in principle, are not very different from particle-filtering half masks. The mask itself consists of the filter material, either entirely or at least to a large extent According to EN 405 [6-79], they are divided into different classes in analogy to screw-on gas filters (types FFA, FFB, FFE, FFK, FFAX and FFSX). The type of gas filter as well as the class can be seen from the marking... 

This means gas filtering half mask for protection against gases and vapors with medium retention capacity. Figure 6.35 shows a combined filter mask protecting against both gases and particles. 

Fig. 6.35 Gas-filtering half mask with safety level FFABEl PI.

P3 (Full-, Half mask) FFP3 Half mask. Quarter mask with a gas filter Gas filtering half mask Compressed-air hose device with half mask and diving apparatus... 

EN 405 2001 Respiratory protective devices -Valved filtering half masks to... 

Respirators should comply with national or European standards such as EN 143 for Particulate filters and EN 149 for Filtering half masks to protect against particles. Distinction has to be made between suitability for solid or liquid particle filtration. 

Filtering half-mask - a facepiece covers nose and mouth which is made of a filtering medium which removes the contaminant. Generally used for up to an 8-hour shift and then discarded... 

Disposable filtering half-mask respirator 4.5 to 50 Positive pressure powered respirator 20 to 2000... 

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