Personal Protective Equipment and Respiratory Protection
This domain tests respirator selection, fit testing, medical evaluation, and protective clothing. Questions often give an exposure level and ask for the minimum acceptable respirator.
Respirator selection
OSHA’s asbestos standard uses assigned protection factors (APFs). A half-mask air-purifying respirator with HEPA/P100 filters has an APF of 10; with a PEL of 0.1 f/cm³, it can be used up to 1.0 f/cm³. A full-face air-purifying respirator has an APF of 50, covering up to 5.0 f/cm³. Higher exposures or inadequate oxygen require supplied-air or other appropriate respiratory protection. Fit testing is required annually and before initial use; medical evaluation is required before fit testing. Facial hair that interferes with the seal is prohibited.
Protective clothing
Workers wear disposable coveralls, hoods, boots, and gloves. Cuffs are taped, and the interface between suit and respirator is sealed as much as practicable. Donning occurs in the clean room; doffing occurs in the dirty room and shower sequence to avoid contaminating skin or street clothes.
Worked example
A personal sample shows 0.6 f/cm³ as an 8-hour TWA. A half-mask APR with P100 has an APF of 10, so its maximum use concentration is 10 × 0.1 = 1.0 f/cm³. Because 0.6 is below 1.0, a half-mask APR is acceptable if fit testing, medical clearance, and cartridge change schedules are in place. At 1.2 f/cm³, a full-face APR would be needed.
Traps
Do not use a surgical mask or dust mask. Do not skip annual fit testing or medical evaluation. Do not wear a respirator over a beard that breaks the seal. Do not remove the respirator before completing decontamination.