Terms and definitions, requirements (basic requirements, sensory requirements, dimensional deviations, nose clips, intrinsic quality (formaldehyde content, pH value, decomposable carcinogenic aromatic amine dyes in dyeing and printing areas, particulate matter filtration efficiency, inhalation resistance, exhalation resistance , the breaking strength of the mask belt and the connection between the mask belt and the mask body), microbial indicators), test methods, inspection rules, marking, packaging, storage and transportation.