Appendix D - Examples of Part 84 Respirator Selection
1. The IDLH for iron oxide is 2,500 mg/m3 and there is sufficient oxygen so that an air-purifying respirator can be used.
2. Iron oxide is not an oil particulate. Therefore, a respirator with a Type N filter can be used.
3. The OSHA PEL for iron oxide is 10 mg/m3. The HR for iron oxide in this example is (25 mg/m3)/(10 mg/m3) = 2.5.
4. A minimally appropriate respirator would be a half-mask respirator (commonly accepted APF = 10) with an N95 filter. The N95 filter service time is limited only by considerations of hygiene, damage, and breathing resistance.
RESPIRATOR SELECTION PROCESS FOR MIXTURE OF COPPER DUST (22 mg/m3) AND OIL MIST (8 mg/m3)
1. The atmosphere is non-IDLH (2,500 mg/m3 for oil mist and 100 mg/m3 for copper) and has sufficient oxygen so that an air-purifying respirator can be used.
2. The OSHA PEL is 1 mg/m3 for copper dust and 5 mg/m3 for oil mist.
3. Oil mist is present; therefore, either an R- or P-series filter should be used.
4. In this example, the HR for copper dust is (22 mg/m3)/(1 mg/m3) = 22, and the HR for the oil mist is (8 mg/m3)/(5 mg/m3) = 1.6. Since the copper dust HR is the higher of the two contaminants, this value should be used to select the appropriate respirator. Because the HR of 22 exceeds the APF of 10 for a half-mask respirator, a minimally appropriate respirator would be a full-facepiece respirator with either an R95 or a P95 filter. If the R95 filter is used, it should be used for one shift only (see Table 1 in Section C) unless the testing previously described has been done to allow more than one shift.
RESPIRATOR SELECTION PROCESS FOR THE INSECTICIDE DUST DINITRO-o-CRESOL (0.6 mg/m3)
1. The IDLH for dinitro-o-cresol is 5 mg/m3 and there is sufficient oxygen so that an air-purifying respirator can be used.
2. Dinitro-o-cresol is a solid particulate with a low vapor pressure, and there is no oil aerosol in this example. Therefore, a respirator with an N-series filter can be used (Note: See discussion on vapor in item 4, below).
3. The OSHA PEL for dinitro-o-cresol is 0.2 mg/m3. The HR in this example for dinitro-o-cresol is (0.6 mg/m3)/(0.2 mg/m3) = 3.
4. A minimally appropriate respirator would be a half-mask respirator (APF = 10) with an N95 filter. The N95 filter service time is limited by hygiene, damage, and breathing resistance. If a particular pesticide (including insecticide) presents a vapor hazard, a combination organic vapor and appropriate particulate filter should be used.
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