Important information about respiratory masks from Wikipedia:

A half mask encloses the nose and mouth, leaving the eye area unobstructed. Unlike a full-face mask, the seal runs across the nose area, which is more difficult to seal.

Depending on the design, particle-filtering half masks or FFP masks ( filtering face pieces , fine dust masks , or respirator filters ) protect against the inhalation of particles and aqueous or oily aerosols . They are usually made entirely of nonwoven fabric with elastic bands and a moldable nosepiece to optimize fit to the face.

When used properly, standardized masks with CE marking can protect against respirable dust and liquid mists within their respective application areas. In addition to the supporting filter material, they contain layers of an electrostatic material ( electret , see also electret filter ). Small dust particles, liquid droplets, and aerosols are trapped by four physical mechanisms (sieve effect, inertia effect, diffusion, electrostatics). ^[4] However, the electrostatic effect diminishes over time due to dust accumulation and moisture penetration. These deposits also lead to a noticeable increase in breathing resistance.

Areas of application include dust protection masks for grinding work in trades or on construction sites, for silo inspections, in mining , or against aerosols , e.g., when applying water-soluble paints with a spray gun or airbrush . Particle-filtering half masks designated as infection protection masks can provide at least partial protection against various airborne pathogens, such as SARS-CoV-2 . ^{[5] [6] [7]} Particle-filtering half masks are usually made entirely of the filter material.

They do not offer protection against gases and vapors, even if they are equipped with an activated carbon insert. This insert serves to protect against unpleasant but harmless organic odors (e.g., when handling slaughterhouse waste, in animal husbandry, or waste disposal). Protection against gases can only be achieved with special gas filters ^[8] .