N99

Noun

 * 1) A  type that efficiently filters out 99% of airborne particulates of 0.3 microns (and all larger particles), but which is not resistant to oils.
 * 2) By extension, filtration  of 99% of airborne particulates
 * 3) A  implementing the N99 standard.

Etymology
From in s.

Noun

 * 1)  N99 standard
 * 2)  N99 filter
 * 1)  N99 filter

Coordinate terms

 * , 99% filtration
 * ,, 99.97% filtration

Related terms

 * oil-resistant filter standard
 * oil-proof filter standard