[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: 30CFR20.8]

[Page 129-130]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 20--ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS--Table of Contents
 
Sec. 20.8  Class 1 lamps.

    (a) Protection against explosion hazards. Unless properly designed, 
class 1 lamps present two sources of probable explosion hazards: 
Ignition of an explosive atmosphere by the heated filament of the bulb 
in case the bulb glass is accidentally broken, and ignition by electric 
sparks or arcs from the battery or connections thereto. MSHA's 
therefore, requires the following safeguards:
    (1) Safety device or design. The lighting unit shall have a safety 
device to prevent the ignition of explosive mixtures of methane and air 
if the bulb glass surrounding the filament is broken. Alternatively, if 
the lamp is designed and constructed of materials that will prevent the 
ignition of explosive mixtures of methane and air by protecting the bulb 
from breakage and preventing exposure of the hot filament, no separate 
safety device is required. Alternative designs will be evaluated by 
mechanical impact tests, temperature tests and thermal shock tests to 
determine that the protection provided is no less effective than a 
safety device.
    (2) Safety device (protection). The design of the safety device and 
the housing which protects it shall be such that the action of the 
safety device is positive; yet the lamp shall not be too readily 
extinguished during normal service by the unnecessary operation of the 
device.
    (3) Locks or seals. For lamps other than flashlights, all parts, 
such as bulb housing and battery container, through which access may be 
had to live terminals or contacts shall be adequately sealed or equipped 
with magnetic or other equally reliable locks to prevent opening by 
unauthorized persons. For flashlights, provision shall be made for 
sealing the battery container.
    (4) Battery current restricted. Unless all current-carrying parts 
including conductors, are adequately covered and protected by the sealed 
or locked compartments, the maximum possible current flow through that 
part shall be limited by battery design, or by an enclosed-type fuse 
inside the sealed or

[[Page 130]]

locked container, to values that will not produce sparks or arcs 
sufficient to ignite an explosive mixture of methane and air.
    (b) Protection against bodily hazard. This hazard is chiefly due to 
the possible burning of the user by electrolyte spilled from the 
battery. MSHA, therefore, requires that:
    (1) Spilling of electrolyte. The lamp shall be so designed and 
constructed that when properly filled the battery will neither leak nor 
spill electrolyte under conditions of normal use. Lamps passing a 
laboratory spilling test will be considered satisfactory in this 
respect, contingent upon satisfactory performance in service.
    (2) Corrosion of battery container. The material of which the 
container is made shall resist corrosion under conditions of normal use.

[Sched. 10C, May 17, 1938, as amended at 5 FR 3467, Aug. 30, 1940; 54 FR 
30513, July 20, 1989]