# 13 Carcinogens (4-Nitrobiphenyl, etc.) — OSHA medical surveillance trigger thresholds by substance

For 13 Carcinogens (4-Nitrobiphenyl, etc.), cfr section is 1910.1003; action level is none defined; pel is none defined (standard prohibits entry to regulated areas without authorization; no numerical PEL stated); surveillance trigger is employees considered for assignment to enter regulated areas, and for authorized employees; exam frequency is at least annually (periodic physical examinations, not less often than annually, following the preassignment examination), recorded from its source on 2026-08-12.

- **Substance:** 13 Carcinogens (4-Nitrobiphenyl, etc.) _(verified: appears in the quote below)_
- **CFR section:** 1910.1003 _(verified: appears in the quote below)_
- **Action level:** none defined
- **PEL:** none defined (standard prohibits entry to regulated areas without authorization; no numerical PEL stated)
- **Surveillance trigger:** employees considered for assignment to enter regulated areas, and for authorized employees
- **Exam frequency:** at least annually (periodic physical examinations, not less often than annually, following the preassignment examination)
- **Record retention:** duration of the employee's employment

## What the source says

> 1910.1003 13 Carcinogens (4-Nitrobiphenyl, etc.)." /> 29 CFR §

## Source

- https://www.law.cornell.edu/cfr/text/29/1910.1003

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/).