Personal protective equipment and respiratory protection
What this domain tests
Respirator selection tied to measured or presumed exposure, plus the medical, fit-testing, and clothing requirements around it.
Rules
- Exposure limits: PEL 0.1 f/cm³ 8-hour TWA; STEL 1.0 f/cm³ over 30 minutes; excursion limit 1.0 f/cm³.
- Selection under 29 CFR 1926.1101(h) scales with the multiple of the PEL: half-mask HEPA APR up to 10×PEL; full-facepiece HEPA APR up to 50×PEL; full-facepiece supplied-air pressure-demand with escape cylinder up to 1,000×PEL; full-facepiece pressure-demand SCBA above 1,000×PEL or where exposure is unknown.
- Without a negative exposure assessment, assume the highest exposure class and use the most protective respirator.
- Medical evaluation before fit testing, then annual fit testing; user seal check at every donning; no facial hair under the sealing surface.
- PPE: disposable coveralls with hood, boot covers, gloves (often doubled), eye protection, taped cuffs. Remove outer clothing in the equipment room, HEPA-vacuum it, shower, and remove the respirator only after decontamination.
- Medical surveillance: baseline within 10 working days of assignment and annually thereafter for workers at or above the PEL 30 or more days per year, or in Class I, II, or III work.
- Cartridges need a written change schedule; HEPA filters are magenta-coded and discarded as asbestos waste.
Worked example
Personal sampling shows 0.8 f/cm³, which is 8×PEL. A half-mask HEPA respirator with an assigned protection factor of 10 yields an effective exposure of 0.08 f/cm³, below 0.1, so it is acceptable. At 1.2 f/cm³ (12×PEL) the half-mask fails and a full-facepiece is required.
Traps
- Confusing the STEL with the 8-hour TWA.
- Fit testing before medical clearance.
- Reusing cartridges without a change schedule.