Mine fires and explosions remain a significant hazard in the mining industry. Since 2000, 18 underground mine fires have occurred in the United States. There were serious underground coal mine explosions in July 2000 at the Willow Creek Mine in Utah (2 fatalities and 8 injuries), in September 2001 at Jim Walter Resources’ No. 5 Mine in Alabama (13 fatalities and 3 injuries), and in January 2003 at the McElroy Mine in West Virginia (3 fatalities and 3 injuries).

The number of fatalities and injuries from mine fires and explosions declined greatly from 1970 to 1999. There were several "zero" years during the late 1990s despite a 700% increase in coal production during the same period. A rise in the number of injuries and fatalities since 2000 has prompted further NIOSH research into the causes and preventability of these accidents. These events, unlike other types of accidents where only a few workers are involved, often extend to every underground worker in the mine.

Since the mid-1990s, our research has led to the development of prevention, detection, control, and survivability technologies to reduce the probability of and fatalities from devastating fires and explosions. Many of these technologies have been adopted by the coal-producing and equipment manufacturing industry and are recognized in Mine Safety and Health Administration (MSHA) rulemaking. These technologies have also contributed to fire and explosion protection improvements in Australia and the Republic of South Africa.

Open industry briefings on mine fire preparedness conducted at NIOSH’s Lake Lynn Lab near Fairchance, PA, have enhanced the mining industry’s awareness of the dangers of underground mine fires. Realistic rescue and response training exercises for federal, state, and mine rescue teams at Lake Lynn have improved the effectiveness of rescue teams during numerous mine emergencies.

Development and implementation of a fire prevention checklist for profiling fire prevention and response capabilities at a mine site have played a key role in preventing and responding to incipient mine fires. NIOSH-developed discriminating fire sensors and optimum deployment strategies based on neural networks and combustion particle detection have reduced the number of false fire alarms when used in mining operations where smoke must be distinguished from normal diesel equipment exhaust.

Implementation of automatic fire suppression systems on conveyor belt drives and underground diesel storage areas has successfully controlled the rapid spread of belt fires within mine entries. NIOSH research on flammability of noise control materials in operator cabs led to MSHA’s acceptance of the American Society for Testing and Materials (ASTM) E-162 Radiant Panel Test as a major criterion in the selection and use of these materials.

Fire and explosion safety expertise, test equipment, and test procedures that we developed for the mining industry have been transferred to other industries. The consensus standard test methods of the ASTM International committee E27 on the Hazard Potential of Chemicals apply to numerous other industries besides mining. Many of NIOSH’s research findings were incorporated into the 2004 revised National Fire Protection Association (NFPA) mining fire protection standards (NFPA 120 (underground coal) and NFPA 122 (metal and nonmetal)).

NIOSH research to determine the risk of ignition of flammable atmospheres by laser-based optical and telecommunications equipment (fiber-optic networks) led to the development of ANSI standards governing the power thresholds for such lasers.

Postexplosion accident investigation and forensics tools were developed and used by MSHA to help understand and identify the root cause of explosions. Blast-resistant seals and performance test methods were developed at Lake Lynn Lab and implemented in partnership with MSHA. Passive and active explosion suppression techniques developed at Lake Lynn are routinely used in underground mines throughout the United States and in other countries, such as Australia and the Republic of South Africa.

Real-time, automated gob gas venthole monitoring and wireless data transmission permits continuous monitoring of individual gob gas ventholes to optimize methane drainage and reduce the potential for explosive methane-air mixtures.

NIOSH testing showed that safety for roof bolter operators could be improved by sweeping the area inby the bolter with a methanometer in addition to the machine-mounted methane monitor. This requirement was implemented in MSHA’s methane testing requirements.

Based on data obtained by NIOSH, the Pennsylvania Bureau of Deep Mine Safety permits the use of powered haulage to evacuate a mine in case of a main mine fan outage. Prior to NIOSH’s evaluation of worker safety during egress, the use of powered haulage was prohibited during main mine fan stoppages.

The mining industry has undergone tremendous advances in technology. These have provided opportunities to increase production and eliminate old hazards. However, they have often created new risks to workers. In many cases, these advances have introduced significant new fire and explosion safety hazards, such as increased methane emissions due to higher production levels. NIOSH research has helped improve fire detection and control and protection for mine workers against the hazards of underground mine fires and explosions.