Worker Protection, Respiratory Protection and PPE
Exposure limits
OSHA 29 CFR 1926.62 sets a permissible exposure limit of 50 µg/m³ as an 8-hour TWA and an action level of 30 µg/m³. Above the action level, periodic monitoring and - if exposure exceeds 30 µg/m³ for more than 30 days a year - medical surveillance. Above the PEL, engineering and work-practice controls, respirators and hygiene facilities are required. Blood lead: 40 µg/dL is the return-to-work trigger; 50 µg/dL triggers medical removal.
Respiratory protection
A written program is required, with a medical evaluation before any fit test, an annual fit test, a user seal check every use, and no facial hair under the seal. HEPA (P100) cartridges are standard. A half-mask air-purifying respirator has an assigned protection factor of 10 and a full-facepiece APR an APF of 50 - match the APF to the expected exposure. Respirators supplement containment, wet methods and HEPA vacuuming; they never replace them.
PPE and hygiene
Disposable coveralls with hood, boot covers, gloves and eye protection, with cuffs taped. Remove PPE in the dirty room, shower, and change into street clothes before leaving. No eating, drinking, smoking or chewing in the work area; wash hands and face before breaks. Keep work clothing separate and launder it at the site, never at home.
Traps
- Mixing up the pairs: 30 µg/m³ action level with 50 µg/m³ PEL; 40 µg/dL return with 50 µg/dL removal.
- Assuming a respirator makes containment or wet methods optional.
- Treating the fit test and the medical evaluation as one step; the medical evaluation comes first.
- Ignoring how PAPRs and supplied-air respirators change the APF.
Rule of thumb
Remember two pairs: 30/50 for air, 40/50 for blood.