Respiratory Protection and Air Monitoring
This domain tests the administrative scaffolding around the respirator - medical clearance, fit testing, seal checks, cartridge schedules - plus the monitoring that decides whether a respirator belongs on the face at all.
Program elements under 1910.134
A written program, a medical evaluation by a physician or other licensed health care provider before fit testing or use, annual fit testing for each make, model, and size, a user seal check at every donning, training, a cartridge change schedule, cleaning and storage, and replacement of worn parts. Facial hair crossing the sealing surface disqualifies a tight-fitting respirator. Even voluntary use requires the information in Appendix D.
Choosing the class
Particulate filters are rated N (not oil-resistant), R (oil-resistant, single shift), and P (oil-proof), at 95, 99, or 100 efficiency. They do nothing for gases. Assigned protection factors: half-mask APR 10, full-facepiece APR 50, loose-fitting PAPR 25, tight-fitting full-facepiece PAPR or supplied-air 1,000, SCBA 10,000. Any IDLH, unknown, or oxygen-deficient atmosphere requires supplied air or SCBA - never an air-purifying respirator.
Monitoring
A four-gas meter (oxygen, LEL, CO, H2S) at the start of every shift and continuously where conditions can change, a PID for volatile organics, and colorimetric tubes for specific gases. Bump test and calibrate; record the results. Action levels: oxygen below 19.5% or above 23.5%, LEL at 10%, and any reading above the applicable exposure limit.
Worked example
A four-gas meter in a basement reads 18.8% oxygen and 15% LEL. Both values are outside action levels, so the atmosphere is oxygen-deficient and potentially explosive; APR entry is prohibited. The space is ventilated from outside and re-tested, and any subsequent entry runs on supplied air with an attendant outside.
Traps that cost marks
Fit testing someone before medical clearance; taking one reading and treating it as the whole shift; handing out N95s for solvent vapor or an unknown atmosphere; and assuming a PID sees everything - it does not detect CO, methane, or many low-ionization compounds.