[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR23.9]

[Page 138-139]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 23--TELEPHONES AND SIGNALING DEVICES--Table of Contents
 
Sec. 23.9  Special requirements for complete devices.

    Telephones and signaling devices will be considered nonpermissible 
if used under any of the followings conditions:
    (a) Without the approval plate, mentioned hereafter.
    (b) With unprotected openings in any of the explosion-proof 
compartments. This condition refers to any openings in these 
compartments, but especially

[[Page 139]]

to those equipped with removable covers.
    (c) If not complete with all of the parts considered in the 
approval.
    (d) If installed or connected otherwise than in accordance with the 
instructions furnished by the manufacturer.
    (e) If modified in any manner not authorized by MSHA.