Dust mask

A dust mask is a flexible pad held over the nose and mouth by elastic or rubber straps to protect against dusts encountered during construction or cleaning activities, such as dusts from drywall, brick, wood, fiberglass, silica (from ceramic or glass production), or sweeping. A dust mask can also be worn to protect against allergens. A dust mask is worn in the same fashion as a paint mask or surgical mask, but it is dangerous to confuse the three because they each protect against specific airborne dangers. Using the wrong mask for a job can present a significant and possibly deadly danger as many dust masks with widely varied levels of protection may look similar, and even masks that do not protect against dust at all, such as paint masks and surgical masks may look similar to dust masks. Misfitting masks are also a danger as they allow material to bypass the mask entirely. A correct fit may not be as critical in masks that are intended to protect against splattering liquids or mists. Dust masks are manufactured to protect against only certain dangers, and do not protect against chemicals such as vapors and mists. For this reason, it is dangerous to confuse dust masks with paint masks.

Dust masks are a cheaper, lighter, and possibly more comfortable alternative to respirators, but may not provide as much protection, and may be more susceptible to misuse or poor fit.

Some dust masks include improvements such as having two straps behind the head (one upper and one lower), having a strip of aluminum on the outside across the bridge of the nose that can be bent for a custom fit, and having a strip of foam rubber on the inside across the bridge of the nose to ensure a good seal even if the aluminum on the outside does not fit.

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Wikipedia