APFs Wait is Rewarded
- By Jerry Laws
- Nov 01, 2003
TWO years ago this month, our cover story fretted that three years had gone
by since OSHA had promised to issue Assigned Protection Factors for respirators.
Why such a long delay? Some end users may not understand or value APFs, but
manufacturers consider them an essential element of a sound respiratory program.
They relied on an existing ANSI standard but knew its APFs differed from NIOSH
recommendations and from APFs within certain substance-specific OSHA
The respiratory community wanted OSHA to end the confusion by filling the APF
gap it had left in its 1998 revised Respiratory Protection Standard, and this
Our anxiety ended June 6, 2003, when OSHA issued its APF proposed rule and
invited comments until Sept. 4. You can turn to page 34 for an explanation of
the proposal by Jay A. Parker, CIH, and Brian Shockley, Q.S.S.P., of Bullard
Company and an excellent chart taken directly from the proposed rule.
The proposed APFs differ somewhat from NIOSH's Respirator Decision Logic
(RDL) and from ANSI Z88.2-1992, the American National Standard on Respiratory
Protection. The RDL and OSHA's proposal call for a 50 APF on full facepiece air
purifying respirators, which is half the 100 APF in Z88.2-1992. Powered air
purifying respirators with hoods or helmets would get a 1,000 APF from OSHA,
which agrees with the ANSI standard but is higher than the RDL. Also, there is a
significant difference for supplied air respirators: OSHA assigns a 50 APF--but
the RDL assigns a 1,000--for half mask, continuous flow or pressure demand SARs;
the opposite is true for full facepiece, continuous flow or pressure demand
Once finalized, the proposed rule will clear the air for the safety and
health professionals who have wrestled with conflicting APF data for years. As
Parker and Shockley explain, "It puts to rest many questions about the
protective capabilities of different respirator types by putting forth
recommendations that rely on scientific methods and validation studies." In the
end, our long wait is rewarded.
This article originally appeared in the November 2003 issue of Occupational Health & Safety.
Jerry Laws is Editor of Occupational Health & Safety magazine, which is owned by 1105 Media Inc.