R99

Noun

 * 1) A  type that efficiently filters out 99% of airborne particulates of 0.3 microns (and all larger particles) and is somewhat resistant to oil.
 * 2) A  implementing the R99 standard.

Etymology
From in s.

Noun

 * 1)  R99 standard
 * 2)  R99 filter
 * 1)  R99 filter

Coordinate terms

 * ,, 99.97% filtration

Related terms

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