Other NIOSH certified particle mask grades include: N95, n99, N100, R95, R99, R100, p95, p99, P100, a total of 9. These protection levels can cover the protection range of N95.
"N" means not resistant to oil, suitable for non oil particles.
"R" means resistant to oil, suitable for oil or non oil particles. If it is used for the protection of oil particles, the service time shall not exceed 8 hours.
"P" means oil proof, suitable for oily or non oily particles. If it is used for oily particles, the service time shall follow the manufacturer's recommendations.
"95", "99" and "100" refer to the level of filtration efficiency when tested with 0.3 micron particles. "95" means that the filtration efficiency is more than 95%, 99 means that the filtration efficiency is more than 99%, and 100 means that the filtration efficiency is more than 99.7%.