---
kind: "section"
citation: "30 C.F.R. § 57.22229"
title: "30"
number: "57.22229"
heading: "Weekly testing (I-A, III, and V-A mines)."
url: "https://uscodex.org/cfr/30/57.22229"
---

# §57.22229. Weekly testing (I-A, III, and V-A mines).

- (a) The mine atmosphere shall be tested for methane and carbon monoxide at least once every seven days by a competent person or an atmospheric monitoring system, or a combination of the two. Such testing shall be done at the following locations:
  - (1) The return of each split where it enters the main return;
  - (2) Adjacent to retreat areas, if accessible;
  - (3) At least one seal of each sealed area, if accessible;
  - (4) Main returns;
  - (5) At least one entry of each intake and return;
  - (6) Idle workings; and
  - (7) **Return air from unsealed abandoned workings.**
- (b) The volume of air (velocity in Subcategory I-A mines) shall be measured at least once every seven days by a competent person. Such measurement shall be done at the following locations:
  - (1) Entering main intakes;
  - (2) Leaving main returns;
  - (3) Entering each main split;
  - (4) Returning from each main split; and
  - (5) In the last open crosscuts or other ventilation openings nearest the active faces where the air enters the return.
- (c) Where such examinations disclose hazardous conditions, affected persons shall be informed and corrective action shall be taken.
- (d) Certification of examinations shall be made by signature and date. Certifications shall be retained for at least one year and made available to authorized representatives of the Secretary.

## Notes

### Amendments

[52 FR 24941, July 1, 1987, as amended at 52 FR 41397, Oct. 27, 1987]

### Authority

Authority: 30 U.S.C. 811.

### Source

Source: 52 FR 24941, July 1, 1987, unless otherwise noted.

### Authority

Authority: 30 U.S.C. 811.

### Source

Source: 50 FR 4082, Jan. 29, 1985, unless otherwise noted.

### Amendments

[52 FR 24941, July 1, 1987, as amended at 52 FR 41397, Oct. 27, 1987]