# 30 CFR 75.403 — Maintenance of incombustible content of rock dust.

- **Chapter:** CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
- **Subchapter:** SUBCHAPTER O—COAL MINE SAFETY AND HEALTH
- **Part:** PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES
- **Subpart:** Subpart E—Combustible Materials and Rock Dusting
- **Snapshot current through:** 2026-08-19
- **Official eCFR:** https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-75/subpart-E/section-75.403

## Current public text

Where rock dust is required to be applied, it shall be distributed upon the top, floor, and sides of all underground areas of a coal mine and maintained in such quantities that the incombustible content of the combined coal dust, rock dust, and other dust shall be not less than 80 percent. Where methane is present in any ventilating current, the percent of incombustible content of such combined dust shall be increased 0.4 percent for each 0.1 percent of methane.

[75 FR 57857, Sept. 23, 2010; 76 FR 35978, June 21, 2011]

## Provenance

- Source: Electronic Code of Federal Regulations, Title 30
- Representation: Realm public-data crosswalk
- Legal status: The eCFR is an editorial compilation; consult the official source before relying on the text.