A dust mask is a flexible paper pad held over the nose and mouth by elastic or rubber straps for personal comfort against non-toxic nuisance dusts. They are not intended to provide protection from toxic airborne hazards.
Dust masks cover the mouth and nose to provide short-term, light-duty breathing protection. They're available in different filtration ratings to get the desired level of protection. Nuisance dust masks filter out dust and mild irritants and are commonly worn at construction and agricultural jobsites.