What does the P in P100 filters indicate?

The designation "P" in P100 filters stands for "Particulate." This classification is part of the NIOSH (National Institute for Occupational Safety and Health) filtration rating system and indicates that the filter is designed to provide a high level of protection against airborne solid and liquid particulates. Specifically, P100 filters are capable of filtering at least 99.97% of airborne particles, including those that are very small, sized at 0.3 microns or larger.

Understanding this classification is critical, particularly in occupational settings where exposure to hazardous dusts, including asbestos fibers, can occur. The effectiveness of the P100 filter makes it a vital piece of personal protective equipment for professionals involved in asbestos-related work, ensuring maximum respiratory safety. This explanation helps emphasize the importance of selecting the appropriate filtration system based on the type of contaminants present in the work environment, specifically those comprising particulate matter.