---
kind: "section"
citation: "30 C.F.R. § 71.702"
title: "30"
number: "71.702"
heading: "Asbestos standard."
url: "https://uscodex.org/cfr/30/71.702"
---

# §71.702. Asbestos standard.

- (a) **Definitions.** Asbestos is a generic term for a number of asbestiform hydrated silicates that, when crushed or processed, separate into flexible fibers made up of fibrils.

  Asbestos means chrysotile, cummingtonite-grunerite asbestos (amosite), crocidolite, anthophylite asbestos, tremolite asbestos, and actinolite asbestos.

  Asbestos fiber means a fiber of asbestos that meets the criteria of a fiber.

  Fiber means a particle longer than 5 micrometers (µm) with a length-to-diameter ratio of at least 3-to-1.

- (b) **Permissible Exposure Limits (PELs)—**
  - (1) **Full-shift limit.** A miner's personal exposure to asbestos shall not exceed an 8-hour time-weighted average full-shift airborne concentration of 0.1 fiber per cubic centimeter of air (f/cc).
  - (2) **Excursion limit.** No miner shall be exposed at any time to airborne concentrations of asbestos in excess of 1 fiber per cubic centimeter of air (f/cc) as averaged over a sampling period of 30 minutes.
- (c) **Measurement of airborne asbestos fiber concentration.** Potential asbestos fiber concentration shall be determined by phase contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in [29 CFR 1910.1001](/cfr/29/1910.1001.md), Appendix A, or a method at least equivalent to that method in identifying a potential asbestos exposure exceeding the 0.1 f/cc full-shift limit or the 1 f/cc excursion limit. When PCM results indicate a potential exposure exceeding the 0.1 f/cc full-shift limit or the 1 f/cc excursion limit, samples shall be further analyzed using transmission electron microscopy according to NIOSH Method 7402 or a method at least equivalent to that method.

## Notes

### Amendments

[73 FR 11304, Feb. 29, 2008, as amended at 73 FR 66172, Nov. 7, 2008]

### Authority

Authority: 30 U.S.C. 811, 813(h), 957.

### Source

Source: 37 FR 6368, Mar. 28, 1972, unless otherwise noted.

### Amendments

[73 FR 11304, Feb. 29, 2008, as amended at 73 FR 66172, Nov. 7, 2008]