Skip to content
MSHA News Release No. 96-017
Mine Safety and Health Administration
Contact: Kathy Snyder
Phone: (703) 235-1452

October 25, 1996


The Mine Safety and Health Administration (MSHA) today issued safety standards to protect miners against hazards from diesel equipment in underground coal mines. The new requirements will help safeguard miners from fires, explosions, toxic exhaust gases, and other dangers that diesels can pose in underground coal operations.

"With diesel use on the rise in the underground coal industry, coal miners need these requirements to help assure them a safe work environment underground," said Davitt McAteer, assistant secretary of labor for mine safety and health. "Until now, federal safety rules for equipment in underground coal mines focused mainly on electrically powered machines."

As internal combustion engines, diesels present a possible explosion risk in the underground coal mine environment where potentially explosive methane gas can occur. High-temperature components of diesel engines also can pose a fire hazard in the presence of coal and other combustibles. Handling and storage of diesel fuels underground can create additional fire dangers. In addition, diesel exhaust can be hazardous to miners.

With adequate safety precautions, diesels can be used safely in underground coal mines, McAteer emphasized.

MSHA's new requirements on diesel-powered equipment in underground coal mines fall into three categories: equipment design and testing, safety standards, and monitoring of exhaust gases.

Under the new rule, all diesel machines for use at the working face of an underground coal mine will have to be MSHA-approved. MSHA approval of diesels for use at the working face, where fire and explosion risks are highest, will require design features to reduce fire and explosion hazards. Electrically powered machines used at the underground coal mine working face already must meet similar approval requirements.

Further safety requirements for diesel equipment in underground coal mines include many features already required on electrically powered equipment such as safe brakes, lights, protective cabs or canopies, automatic fire suppression systems, and machine-mounted methane monitors. MSHA's new rule on diesels in underground coal mines also requires engine maintenance by persons adequately trained for the task and covers the safe storage and handling of diesel fuel.

In addition, under the new rule all diesel engines must undergo emissions testing to receive MSHA approval for use anywhere in an underground coal mine. Diesels in underground coal mines must use low-sulfur fuel. A specific ventilation requirement will protect miners from toxic gaseous emissions. Under the new rule, mine operators will monitor carbon monoxide and nitrogen dioxide levels in areas where diesels are used and if concentrations are too high, must take corrective action.

Diesel units operating in U.S. underground coal mines have increased from roughly 150 in 1974 to more than 2,900 units in 1995, with an increase to some 4,000 units possible by the year 2000. Diesel machines most often used in underground coal mines include personnel carriers, utility trucks, and tractors. Other types of underground coal mine equipment that may be diesel powered include generators, scoops, hydraulic pumps, compressors, welders, shuttle cars, road graders and roof bolting machines.

MSHA's new rule on the use of diesel-powered equipment in underground coal mines becomes effective in 6 months, except for specific provisions scheduled to be phased in over a period of 30 days to 36 months. Copies of the diesel rule are available from MSHA's Office of Standards, Regulations and Variances, 4015 Wilson Blvd., Arlington, VA 22203, telephone (703) 235-1910, or may be found on MSHA's home page on the World Wide Web at under "Statutory and Regulatory Information."