30 CFR § 71.702 - Asbestos standard.

---
identifier: "/us/cfr/t30/s71.702"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 71.702 - Asbestos standard."
title_number: 30
title_name: "Mineral Resources"
section_number: "71.702"
section_name: "Asbestos standard."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "O"
subchapter_name: "COAL MINE SAFETY AND HEALTH"
part_number: "71"
part_name: "MANDATORY HEALTH STANDARDS—SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811, 813(h), 957."
regulatory_source: "37 FR 6368, Mar. 28, 1972, unless otherwise noted."
cfr_part: "71"
---


# 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, 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.

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