# Asbestos — OSHA medical surveillance trigger thresholds by substance

For Asbestos, cfr section is 1910.1001; action level is none defined; pel is 0.1 fiber per cubic centimeter of air as an eight (8)-hour time-weighted average (TWA); excursion limit: 1 f/cc averaged over a sampling period of thirty (30) minutes; surveillance trigger is exposed to airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit; exam frequency is annually (periodic medical examinations shall be made available annually), recorded from its source on 2026-08-12.

- **Substance:** Asbestos _(verified: appears in the quote below)_
- **CFR section:** 1910.1001 _(verified: appears in the quote below)_
- **Action level:** none defined
- **PEL:** 0.1 fiber per cubic centimeter of air as an eight (8)-hour time-weighted average (TWA); excursion limit: 1 f/cc averaged over a sampling period of thirty (30) minutes
- **Surveillance trigger:** exposed to airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit _(verified: appears in the quote below)_
- **Exam frequency:** annually (periodic medical examinations shall be made available annually)
- **Record retention:** duration of employment plus thirty (30) years

## What the source says

> <https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=b3c19faa4963f563c95da8d16744338e&term_occur=999&term_src=Title:29:Subtitle:B:Chapter:XVII:Part:1910:1910.1001> HEPA filter . (l) Medical surveillance —(1) General —(i) Employees covered . The employer shall institute a medical surveillance program for all employees who are or will be exposed to airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit.

## Source

- https://www.law.cornell.edu/cfr/text/29/1910.1001

Last verified: 2026-08-12. Review by: 2027-02-08.
Part of [OSHA medical surveillance trigger thresholds by substance](https://referencesource.org/osha-medical-surveillance-triggers/).