Niosh N95 N100 Respirator Specifications

National Institute for Occupation Safety and Health (NIOSH) is a federal agency dedicated to preventing job-related injuries and illnesses by administering research, creating direction and providing official suggestions, spreading information and replying to requests for workplace health-hazard assessments. NIOSH approves a variety of particulate filtering face piece respirators, such as the N95 and N100. These respirators protect workers by filtering molecules out of air they breathe. The N95 and N100 are two of seven classes of filters for NIOSH-approved face piece respirators. N95 is the most common respirator used today, according to NIOSH.

Oil Resistance

• When approving face piece respirators, NIOSH considers a variety of factors, including oil resistance. Neither N95 nor N100 respirators are oil resistant. If an oil-resistant respirator is required, see the Other Respirator Classes section below.

Particle Filtration

• NIOSH only approves face piece respirators that provide 95 percent filtration or greater. The N95 meets the standard, as it provides 95 percent filtration of mobile particulate molecules. With 99.9 percent or greater particulate filtration, the N100 exceeds the NIOSH minimum filtration standard.

Other Respirator Classes

• Other NIOSH-approved respirators include the N99, R95, P95, P99 and P100. The numerals and letters stand for the percentage of filtrating airborne particles and how resistant the respirators are to oil. For instance, the N99 is not resistant to oil and filters 99 percent of all mobile molecules. The R95 is somewhat resistant to oil and provides 95 percent filtration. The P99 is strongly resistant to oil and filters 99 percent of airborne molecules.

  Which respirator works best depends on the type of the environment in which it is used. In most cases, oil resistance is not required but sometimes is vital. Ultimately, it's the employer's responsibility to determine what respirator will work best for particular circumstances, but NIOSH can provide recommendations to assist in making that decision.