Dust mask

A dust mask is a flexible paper pad held over the nose and mouth made for protection against chronically toxic nuisance dusts, like from occupational exposure to plant dusts like hay. They are not intended to provide protection from most airborne hazards. The European FFP1 mask, the lowest-grade standard available in the jurisdiction, is an example of a dust mask, being only certified to remove ~80% of dusts and mists.

Dust masks are used in environments with dusts encountered during construction or cleaning activities, biological hazards from farming, or sweeping. A dust mask can also be worn in environments with allergens such as tree and grass pollen.

Use
A notable occupational use of dust masks is in farming, where dust masks are used to avoid the effects of farmer's lung, a disease caused by the inhalation of dusts from agricultural products. The toxicity mainly comes from allergy to mold in the dust, which can lead to lung damage due to the immune response, as opposed to an inherent toxicity in the dust itself.

In a study following treating Farmer's lung with dust masks, the dust mask selected for the study was only tested to a filtration standard of 99.9% filtration of dusts greater than 1 micron (1000 nm).

Regulation
Europe has a standard for masks whose filtration efficiency goes at or below 90%:
 * The FFP1 standard allows up to 22% inward leakage and filtration efficiency of at least 80%.

Some Asian countries have regulations for dust-grade masks intended for everyday civilian use as opposed to occupational use. These include:
 * China, GB/T 32610:2016 – masks for daily protection


 * South Korea, KF80

Dust masks have been certified by the United States Bureau of Mines since the 1930s, until being phased out after the passage of 42 CFR Part 84.


 * D or DM respirators, standing for 'dust' and 'dust/mist' approval respectively, without approval for 'fumes,' asbestos, radionuclides, or any certified (30 CFR) HEPA filtration.