N-95 Masks: Whats in a name

Ive seen the name bantered around a bit and I have done so myself but I just wanted to put up a post explaining what exactly N-95 et al means


The letter before the number indicates what type of environment the mask is to be used in:

The selection of N-, R-, and P-series filters depends on the presence or absence of oil particles, as follows:

If no oil particles are present in the work environment, use a filter of any series (i.e., N-, R-, or P-series).

If oil particles (e.g., lubricants, cutting fluids, glycerine, etc.) are present, use an R- or P-series filter. Note: N-series filters cannot be used if oil particles are present.

If oil particles are present and the filter is to be used for more than one work shift, use only a P-series filter.

Note: To help you remember the filter series, use the following guide:
N for Not resistant to oil,
R for Resistant to oil
P for oil Proof
www.cdc.gov...

The number after the letter is an indication of the efficency of the filter medium. 95 means 95% etc etc.

N100-Particulate Filter (99.97% filter efficiency level) effective against particulate aerosols free of oils; time use restrictions may apply

N99-Particulate Filter (99% filter efficiency level) effective against particulate aerosols free of oil; time use restrictions may apply

N95-Particulate Filter (95% filter efficiency level) effective against particulate aerosols free of oil; time use restrictions may apply

www.cdc.gov...

A pretty good primer on the different type of masks
www.cdc.gov...

All of this is predicated on a proper fitting mask. At the hospital we are required to be fit tested once a year. That involves us going under a hood with a mask on then albuterol is sprayed intot he chamber. If you can smell it then the mask is not properly fitted etc.



[edit on 8/8/09 by FredT]

[edit on 8/8/09 by FredT]

[edit on 8/8/09 by FredT]