The disposable 3M 4251 half mask is suitable when working with adhesive, paints, solvents, resins and varnishes. This product offers protection from particulates and organic vapours, and utilises twin inhalation valves and parabolic valves to reduce heat build-up and breathing resistance. In addition, the single-piece integral construction makes for an easy to use maintenance-free product.
Delivery Options:
FREE DELIVERY OVER £ 75 NET
Half mask respirators enclose both the nose & mouth & as such are termed half masks. Half masks are made from natural or synthetic rubber that allows sufficient flexibility for facial contours. Every half mask is required to reach the EN 140:1998 safety standard & will protect against both very fine particulates & gases when used with the correctly selected mask filters for the hazard.
Half mask respirators with the P3 filter (FFP3 Equivalent) provide an APF 20 which is the correct grade of protection against viruses such as Covid 19 & SARS.
Half masks have been designed to be worn for long periods however as per HSE guidance regular breaks should be taken after less than an hour of continuous use as the RPE may start to feel uncomfortable. This reduces the risk that the user will loosen the straps thus reducing the seal & protection.
All half mask respirators used on a regular basis should be thoroughly checked at least once a month. If the half mask dust respirator is only used occasionally it should be examined carefully before use.
Depending on the filter selected, Half face masks will provide an APF 4 (P1 Filter), APF 10 (P2 Filter) & an APF 20 (P3 Filter).
Half masks will also protect against gases/vapours including organic/inorganic fumes & acid gases as well as ammonia & mercury. The correct fume filter for the hazard encountered can be found in our mask filter category.
Half mask respirators should not be used in oxygen deficient environments.
Always follow the manufacturers RPE advice when using the mask however generally a good seal can be checked by covering the inlet valve / filter with your hand, inhaling & holding your breath for circa 10 seconds. The mask suction should not loosen. If it does loosen readjust the head hardness straps & retry until a good seal has been achived.
It is the company’s legal responsibility to ensure their RPE wearers have been face fitted. Protective Masks Direct ltd provide face fitting across the whole of the UK.