A medical mask provides physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. Unlike other masks, a medical mask meets very strict guidelines for filtration, splash resistance, and breathability. In addition to other criteria, a medical mask must have BFE (bacterial filtration efficiency) of 95% or higher.
However, without filter layer, 2-ply and cloth mask offer inconsistent protection against pollution, viruses, or bacteria. Plus, cloth masks shed fibers every time they are laundered, making it even less effective over time.