What does P100 mean on a respirator?

Filters are a bit like shoes – the sizes are different depending on what country you’re in. With filters, the rating depends on which country’s standards they are going by. Let’s find out how they compare…

Basically if you see a filter with a N95, R95, P95, N99, P99, N100 or P100 rating, then they have been given the US rating by the National Institute for Occupational Safety and Health (NIOSH) in America. These ratings all have equivalents in Australian and New Zealand standards, which reflect European standards.

This particular set of ratings relate to particulate filters. The first letter represents their resistance level to oil, and the number represents the level of protection. A P100 rating is the highest level of personal respiratory protection, and can block out 99.9% of particles as long as the mask and filter are fitted correctly (learn more about Fit Testing here)

In short, the US N95, R95 and P95 are equivalent to a New Zealand/European P2 filter, where the N100 or P100 is equivalent to a New Zealand/European P3 filter.