This standard specifies the classification, technical requirements, testing methods, inspection rules, labeling, packaging, storage and transportation of reusable civilian masks. This standard applies to reusable civilian masks used to block microorganisms, droplets, pollen and other particles in daily life. This standard does not apply to children's masks, as well as respiratory protective equipment for special industries such as medical environments, hypoxic environments, underwater operations, escapes, firefighting and industrial dust control. This standard does not apply to discarded masks.