N95 and R95 Respirators – What’s The Difference?

There are a lot of different facepiece respirators available. If you’re like most people, you’ll be confused if you find these other masks and won’t be sure which to buy. Respirators are designated by a letter and number. NIOSH standards define these categories of filters: N95, N99, N100, R95, R99, R100, P95, P99, and P100.

But what does these numbers mean? Are they resistant to oil? This is primarily a concern in industrial environments but still something to keep in mind. Oil aerosols can degrade the performance and efficiency of your mask’s filter media by removing electrostatic charges. Electrostatic charges between the layers of filter media act as a magnet and help trap airborne particles.

N95 vs R95 vs P95

  • N – Not Resistant to Oil
  • R – Somewhat Resistant to Oil.
    R masks (somewhat resistant to oil) are only certified for up to 8 hours of service life.
  • P – Strongly Resistant to Oil (Oil Proof).
    P (strongly resistant to oil) are certified for up to 40 hours or 30 days of use, whichever comes first.

N95 vs N99 vs N100

  • N95 respirators remove at least 95% of airborne particles with a size of 300nm
  • N99 respirators remove at least 99% of airborne particles
  • N100 respirators remove at least 99.97% of airborne particles

Here’s another thing to keep in mind — N99 and N100 masks are more dense than N95 masks, making it harder to breathe, which can lead to perspiration and moisture. Moisture can saturate the filter media and make it harder to breathe while also degrading filter efficiency. A N95 mask is probably your best option if you expect to be physically active.

Seven Classes of Filters
There are seven classes of filters for NIOSH-approved filtering facepiece respirators available at this time. Ninety-five percent is the minimal level of filtration that will be approved by NIOSH.

The N, R and P designations refer to the filter’s oil resistance as described below:

  • N95 – Filters at least 95% of airborne particles. Not resistant to oil.
  • Surgical N95 – A NIOSH-approved N95 respirator that has also been cleared by the Food and Drug Administration (FDA) as a surgical mask .
  • N99 – Filters at least 99% of airborne particles. Not resistant to oil.
  • N100 – Filters at least 99.97% of airborne particles. Not resistant to oil.
  • R95 – Filters at least 95% of airborne particles. Somewhat resistant to oil.
  • P95 – Filters at least 95% of airborne particles. Strongly resistant to oil.
  • P99 – Filters at least 99% of airborne particles. Strongly resistant to oil.
  • P100 – Filters at least 99.97% of airborne particles. Strongly resistant to oil.

Filtering Facepiece Respirator (FFR) Labels|
Individual filtering facepiece respirators are required to have the following markings:

  1. Name of Approval holder/manufacturer business name, a registered trademark, or an easily understood abbreviation of the applicant/approval holder’s business name as recognized by NIOSH. When applicable, the name of the entity to which the FFR has been private labeled by the approval holder may replace the approval holder business name, registered trademark, or abbreviation of the approval holder business name as recognized by NIOSH.
  2. NIOSH in block letters or the NIOSH logo
  3. NIOSH Testing and Certification approval number, e.g. TC-84A-XXXX.
  4. NIOSH filter series and filter efficiency level, e.g. N95, N99, N100, R95, P95, P99, P100
  5. Model Number or part number: The approval holder’s respirator model number or part number, represented by a series of numbers or alphanumeric markings, e.g. 8577 or 8577A.

NIOSH recommends the lot number and/or date of manufacture also be included, however, this is not required.

Sample of a generic filtering facepiece respirator with appropriate markings.