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Performance Evaluation of DM and DFM Filter Respirators—WORKING DRAFT 9.15.92

Industrial Hygiene Manual (IHM)[1] and 1984 Industrial Hygiene Technical Manual (IHTM)[2]. The latter Publication was replaced in 1990 by the OSHA Technical Manual (OTM). OSHA's 1976 APFs from their THM are given in Tables A and B of this evaluation. OSHA cited a Los Alamos Scientific Laboratory publication written by Hyatt as the source for their APFs.[3] OSHA's 1984 APF in their IHTM were reproduced from those given in the nonregulatory 1980 ANSI Z88.2-1980 American National Standard[4] and were preceded by the following explanatory material:

8. [Assigned] Protection Factors. The protection afforded by respirators is dependent upon the seal of the facepiece to the face, leakage around valves, and leakage through or around cartridges or canisters. Depending on these criteria, the degree of protection may be ascertained and a relative safety factor assigned [Assigned] Protection factors are only applicable if all elements of an effective respirator program are in Place and being enforced.

a. The [assigned] protection factor is a ratio of the air contaminant concentration outside the respirator to the air contaminant concentration inside the respirator facepiece. The higher the [assigned] protection factor, the greater the degree of protection offered by the respirator.

b. [Assigned] Protection factors are used in conjunction with permissible exposure limits of contaminants to estimate the upper concentration limits to which respirators can be utilized safely. Table V–3, which is reproduced from ANSI Z88.2–1980, provides [assigned] protection factors and explanations for various types of respirators.

c. [Assigned] Protection factors are invalid when employees remove their respiratory protection for unspecified periods while in the contaminated atmosphere.

NOTE: Field studies of respirator performance have not correlated well with the laboratory test data. Hence, the reported values should only be taken as estimates. For example, recent studies have found that Powered Air-Purifying Respirators (PAPR's) have not achieved the [assigned] protection factors suggested by laboratory data.[5]

The 1980 APFs from the ANSI Z88.2-1980 nonregulatory consensus standard and OSHA's 1984 APFs are given in Table C of this evaluation.

  1. ↑ OSHA: Industrial Hygiene Manual, Chapter III—OSHA Standard Method for Determination of Respiratory Protection Program Acceptability (June 28, 1976), Figures III-5 and III-6, pp. 89-90.
  2. ↑ OSHA: Industrial Hygiene Technical Manual, Chapter V—Respiratory Protection (March 30, 1984), and amended by OSHA Instruction CPL 2–2.20 A CH–1, October 29, 1984), pp. 75–77.
  3. ↑ Hyatt E.C.: Respirator Protection Factors. Los Alamos Scientific Laboratory, Informal Report No. LA-6084-MS (1976), Table I, p. 4.
  4. ↑ American National Standards Institute, Inc: American National Standard Practices for Respiratory Protection, ANSI 288.2-1980, New York, New Yorks, (1960), Table 5, pp. 21-23.
  5. ↑ OSHA: Industrial Hygiene Technical Manual, Chapter V—Respiratory Protection, Issued by OSHA Instruction CPL 2-2.20 A, (March 30, 1964) and amended by OSHA Instruction CPL 2-2.20 A CH-1, October 29, 1984), pp. 63-64.
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