OSHA PEL for lead, the action level and the Cal/OSHA limit

OSHA PEL for lead

The OSHA permissible exposure limit (PEL) for lead is 50 µg/m³ (0.05 mg/m³) of air as an 8-hour time-weighted average (TWA). The action level is 30 µg/m³ as an 8-hour TWA. Both figures apply under the general industry standard, 29 CFR 1910.1025, and the construction standard, 29 CFR 1926.62.

Where the lead exposure limits are set

Table Z-1 gives no number for "Lead, inorganic (as Pb)" (CAS 7439-92-1). Its row points to 1910.1025, where paragraph (c)(1) sets the PEL (Table Z-1).

The general industry lead standard covers metallic lead, all inorganic lead compounds and organic lead soaps. Other organic lead compounds fall outside it. It excludes construction and agricultural operations covered by part 1928.

Tetraethyl lead and tetramethyl lead each have a separate PEL of 0.075 mg/m³ as Pb, with a skin designation. Don't apply the inorganic lead limit to these compounds (Table Z-1).

Permissible exposure limit for lead on long shifts

For shifts longer than 8 hours, divide 400 by the hours worked that day. The maximum is 40 µg/m³ for 10 hours, or about 33 µg/m³ for 12 hours (400 ÷ 12). Paragraph (c)(2) gives this formula in both 1910.1025 and 1926.62.

Small nonferrous foundries with fewer than 20 employees have a 75 µg/m³ engineering and work-practice control target. That does not raise their PEL: it stays at 50 µg/m³, with respirators required to cover the gap (1910.1025(e)).

What the action level triggers

The action level is measured without regard to respirator use. In general industry, exposure at or above it for more than 30 days a year requires medical surveillance. Blood lead testing is at least every 6 months. It moves to every 2 months after a result at or above 40 µg/100 g, until two consecutive results are below 40, and to at least monthly during medical removal (1910.1025(j)).

Air limits and blood lead removal thresholds use different units. General industry requires removal when periodic and follow-up blood tests both reach 60 µg/100 g. An average of 50 µg/100 g also triggers removal, unless the last result is below 40. That average uses the last three tests or all tests over the past six months, whichever period is longer. Return takes two consecutive tests below 40 µg/100 g (1910.1025(k)).

Construction uses a different threshold: periodic and follow-up blood tests at or above 50 µg/dl. Return there takes two consecutive tests below 40 µg/dl. Testing is every 2 months for the first 6 months, then every 6 months. A result at or above 40 µg/dl moves it back to every 2 months, and removal makes it monthly (1926.62(j) and (k)).

Cal/OSHA, NIOSH and ACGIH values

California's lower limits took effect January 1, 2025 (Standards Board). Use the current Title 8 standards rather than older summaries quoting 50 µg/m³.

California's limits appear in §5198 for general industry and §1532.1 for construction. The construction standard allows an interim PEL of 25 µg/m³ for abrasive blasting until January 1, 2030. In lead-acid battery manufacturing the PEL is still 10 µg/m³, but §5198 sets a separate engineering-control level of 50 µg/m³, falling to 40 µg/m³ on January 1, 2030. Respirators still have to keep exposure at or below the PEL. NIOSH and ACGIH values are recommendations, not federal OSHA PELs.

Is the federal lead PEL changing?

The July 1, 2025 OSHA proposed rule titled "Lead" addresses respirator provisions, not the PEL or action level. A proposal does not change the enforceable limit. The PEL is still 50 µg/m³. Check the Federal Register for any final rule, since the proposal is not final.

RegAffairs AI's answer on the OSHA PEL for lead links to the source records used for this question.