NIOSH requires a respirator to pass the 0.3 micron sodium chloride test at 95 % efficiency to be labeled an N95. The N stands for not resistant to oil penetration. Respirators for use in some industrial applications may require respirators with an R (resistant to oil) or P (non-penetrated by oil). OSHA requires that a respiratory protection program be developed for the proper use of respirators including written procedures, medical screening, training, and fit testing.