Particulate filters and vapor cartridges are used to filter airborne contaminants in reusable half-mask or full-face respirators. They are NIOSH-rated and employed according to the environment and type of respiratory threats to be filtered. Filters and cartridges can be swapped out depending on the contaminant to be screened. When they become dirty or the sort of pollutant changes, they are replaced. Welding, metalworking, carpentry, chemical manufacture, and healthcare are just a few of the industries and applications where masks are used.