IC 9470 

INFORMATION CIRCULAR/2004 

Department of Health and Human Services

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Analysis of Mine Fires for All 

U.S. Underground and Surface 

Coal Mining Categories: 

1990--1999 
Information Circular 9470 

Analysis of Mine Fires for All U.S. Underground and Surface 

Coal Mining Categories: 1990–1999 

By Maria I. De Rosa 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
 Centers for Disease Control and Prevention
 

National Institute for Occupational Safety and Health
 

Pittsburgh Research Laboratory
 

Pittsburgh, PA
 

September 2004 
ORDERING INFORMATION 

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This document is the public domain and may be freely copied or reprinted. 

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DHHS (NIOSH) Publication No. 2004–167 
CONTENTS
 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Page 

1 
 

Introduction ................................................................................... 2 
 

Methodologies ................................................................................. 2 
 

Fire data analysis for all coal mining categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 
 

Underground coal mine fires .................................................................... 3 
 

Ignition source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 
 

Method of detection ........................................................................ 8 
 

Suppression method ........................................................................ 9 
 

Equipment involved ........................................................................ 9 
 

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 
 

Burning materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 
 

Fire injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 
 

Surface of underground coal mine fires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 
 

Ignition source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 
 

Method of detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 
 

Suppression method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 
 

Equipment involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 
 

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 
 

Burning materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 
 

Fire injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 
 

Surface coal mine fires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 
 

Ignition source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 
 

Method of detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 
 

Suppression method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 
 

Equipment involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 
 

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 
 

Burning materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 
 

Fire injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 
 

Coal preparation plant fires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 
 

Ignition source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 
 

Method of detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 
 

Suppression method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 
 

Equipment involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 
 

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 
 

Burning materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 
 

Fire injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 
 

Summary of major fire and fire injury findings for all coal mining categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 
 

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 
 

Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 
 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 
 

ILLUSTRATIONS 

1. Number of fires and fire injuries for underground coal mines by state, 1990–1999 ....................... 4 
 

2.	 Number of fires, fire injuries, risk rates, and coal production for underground coal mines by time period and
 

employees' working hours, 1990–1999 ...................................................... 4 
 

3. Major variables for underground coal mine fires, 1990–1999 ........................................ 8 
 

4. Number of fires and fire injuries for surface of underground coal mines by state, 1990–1999 . . . . . . . . . . . . . . . 11 
 

5.	 Number of fires, fire injuries, and risk rates for surface of underground coal mines by time period and
 

employees' working hours, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 
 

6. Major variables for surface of underground coal mine fires, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 
 
ILLUSTRATIONS—Continued 

7. Number of fires and fire injuries for surface coal mines by state, 1990–1999 ............................ 

Page 

17 
 

8.	 Number of fires, fire injuries, risk rates, and coal production for surface coal mines by time period and 

employees' working hours, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 
 

9 Major variables for surface coal mine fires, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 
 

10. Number of fires and fire injuries for coal preparation plants by state, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . 23 
 

11 Number of fires, fire injuries, and risk rates for coal preparation plants by time period and employees'
 

working hours, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 
 

12. Major variables for coal preparation plant fires, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 
 

13.	 Number of fires, fire injuries, risk rates, and coal production (underground and surface coal mines only) for all 

coal mining categories by time period and employees' working hours, 1990–1999 . . . . . . . . . . . . . . . . . . . . . 31 
 

TABLES 

1.	 Number of fires, fire injuries, and risk rates for underground coal mines by state, employees' working hours, 

lost workdays, and coal production, 1990–1999 ............................................... 3 
 

2.	 Number of fires, fire injuries, and risk rates for underground coal mines by time period, employees' working
 

hours, lost workdays, and coal production, 1990–1999 .......................................... 5 
 

3. Number of fires for underground coal mines by ignition source and time period, 1990–1999 ............... 5 
 

4. Number of fires for underground coal mines by method of detection and time period, 1990–1999 ........... 5 
 

5. Number of fires for underground coal mines by suppression method and time period, 1990–1999 ........... 6 
 

6. Number of fires for underground coal mines by equipment involved and time period, 1990–1999 ........... 6 
 

7. Number of fires for underground coal mines by location and time period, 1990–1999 ..................... 6 
 

8. Number of fires for underground coal mines by burning material and time period, 1990–1999 .............. 7 
 

9.	 Number of fire injuries per number of fires causing injuries and total fires in underground coal mines by year,
 

ignition source, equipment involved, and location, 1990–1999 .................................... 7 
 

10.	 Number of fires, fire injuries, and risk rates for surface of underground coal mines by state, employees'
 

working hours, and lost workdays, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 
 

11.	 Number of fires, fire injuries, fire fatalities, and risk rates for surface of underground coal mines by time period,
 

employees' working hours and lost workdays, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 
 

12. Number of fires for surface of underground coal mines by ignition source and time period, 1990–1999 . . . . . . . 13 
 

13. Number of fires for surface of underground coal mines by method of detection and time period, 1990–1999 . . . 13
 

14. Number of fires for surface of underground coal mines by suppression method and time period, 1990–1999 . . . 13
 

15. Number of fires for surface of underground coal mines by equipment involved and time period, 1990–1999 . . . 13
 

16. Number of fires for surface of underground coal mines by location and time period, 1990–1999 . . . . . . . . . . . . 14 
 

17. Number of fires for surface of underground coal mines by burning material and time period, 1990–1999 . . . . . 14 
 

18.	 Number of fire injuries per number of fires causing injuries and total fires at surface of underground coal
 

mines by year, ignition source, equipment involved, and location, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . 14 
 

19.	 Number of fires, fire injuries, and risk rates for surface coal mines by state, employees' working hours, lost
 

workdays, and coal production, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 
 

20.	 Number of fires, fire injuries, fire fatalities, and risk rates for surface coal mines by time period, employees'
 

working hours, lost workdays, and coal production, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 
 

21. Number of fires for surface coal mines by ignition source and time period, 1990–1999 . . . . . . . . . . . . . . . . . . . 17 
 

22. Number of fires for surface coal mines by method of detection and time period, 1990–1999 . . . . . . . . . . . . . . . 19 
 

23. Number of fires for surface coal mines by suppression method and time period, 1990–1999 . . . . . . . . . . . . . . . . 19 
 

24. Number of fires for surface coal mines by equipment involved and time period, 1990–1999 . . . . . . . . . . . . . . . . 19 
 

25. Number of fires for surface coal mines by location and time period,1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . 19 
 

26. Number of fires for surface coal mines by burning material and time period, 1990–1999 .................. 20 
 

27.	 Number of fire injuries per number of fires causing injuries and total fires at surface coal mines by year, 

ignition source, equipment involved, and location, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 
 
TABLES—Continued 

28.	 Number of fires, fire injuries, and risk rates for coal preparation plants by state, employees' working hours, 

and lost workdays, 1990–1999 ............................................................. 

Page 

24 
 

29.	 Number of fires, fire injuries, and risk rates for coal preparation plants by time period, employees' working 

hours, and lost workdays, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 
 

30. Number of fires for coal preparation plants by ignition source and time period, 1990–1999 . . . . . . . . . . . . . . . . 24 
 

31. Number of fires for coal preparation plants by method of detection and time period, 1990–1999 . . . . . . . . . . . . 25 
 

32. Number of fires for coal preparation plants by suppression method and time period, 1990–1999 . . . . . . . . . . . . 25 
 

33. Number of fires for coal preparation plants by equipment involved and time period, 1990–1999 . . . . . . . . . . . . 25 
 

34. Number of fires for coal preparation plants by location and time period,1990–1999 . . . . . . . . . . . . . . . . . . . . . . 26 
 

35. Number of fires for coal preparation plants by burning material and time period, 1990–1999 . . . . . . . . . . . . . . . 26 
 

36.	 Number of fire injuries per number of fires causing injuries and total fires at coal preparation plants by year, 

ignition source, equipment involved, and location, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 
 

37. Major fire findings for all coal mining categories, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 
 

38. Major fire injury findings for all coal mining categories, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 
 

39.	 Number of fires, fire injuries, fire fatalities, and risk rates for all coal mining categories by time period,
 

employees working hours, lost workdays, and coal production, 1990–1999 . . . . . . . . . . . . . . . . . . . . . . . . . . 31 
 

40. Major findings for underground coal mine fires, 1978–1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 
 

UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 

hr hour(s) 

min minute(s) 

st short ton 
ANALYSIS OF MINE FIRES FOR ALL U.S. UNDERGROUND
 

AND SURFACE COAL MINING CATEGORIES: 1990–1999
 

By Maria I. De Rosa1 

1

Industrial hygienist, Pittsburgh Research Laboratory, National Institute for Occupational Safety and Health, Pittsburgh, PA. 

ABSTRACT

 This report analyzes mine fires for all U.S. underground and surface coal mining categories by state and 

2-year time periods during 1990–1999. Risk rate values are derived, and ignition source, methods of fire 

detection and suppression, and other variables are examined. The data were derived from Mine Safety and 

Health Administration (MSHA) mine fire accident publications and verbal communications with mine 

personnel. The analysis will provide the National Institute for Occupational Safety and Health, MSHA, and 

the mining industry with a better understanding of the causes and hazards associated with mine fires and will 

form a basis for future fire research programs. 
2 

INTRODUCTION
 

Coal mine fires pose a constant danger to the safety of miners 

and to their livelihood. Underground mine fires pose an added 

hazard because of the confined environment with remote exits. 

Enactment of safety regulations [30 CFR2

2

Code of Federal Regulations. See CFR in references. 

75 and 77] for underground coal mines and surface coal operations has greatly improved the safety of miners. However, mine fires and fire injuries remain serious hazards for all coal mining operations. 

This report analyzes mine fires and fire injuries for all U.S. 

coal mining categories (underground coal mines, surface of 

underground coal mines, surface coal mines, and coal preparation plants) during 1990–1999. Fires involving contractors are 

also included in the analysis. Similar analyses (for underground 

coal mines only) by the former U.S. Bureau of Mines (USBM) 

were reported by McDonald and Pomroy [1980] and Pomroy 

and Carigiet [1995] for 1950–1977 and 1978–1992, respectively. For comparison purposes, data for 1978–1992 are mentioned in the "Underground Coal Mine Fires" section of this 

report. Detailed analyses of mobile equipment fires for all underground and surface coal and metal/nonmetal mining categories during 1990–1999 have recently been reported by NIOSH 

[De Rosa 2004]. 

Risk rate values (fire and injury risk rates) for the 10-year 

period (1990–1999) and for five successive 2-year periods 

within the 10-year period are derived. Risk rate values for individual states for the 10-year period are also derived. Other 

variables by state and time period include employees' working 

hours, lost workdays, and coal production (underground and 

surface coal mines only). The number of fire fatalities is reported by time period. Variables such as ignition source, 

method of detection and suppression, equipment involved, 

location, and burning material are reported by five 2-year 

periods only. Furthermore, the number of fire injuries per 

number of fires causing injuries and total fires has been 

analyzed by year, ignition source, equipment involved, and 

location. For comparison purposes, the major fire and fire 

injury findings for all coal mining categories have been 

reported. 

The data in this report were derived from "Injury Experience 

in Coal Mining" [MSHA 1991a, 1992, 1993, 1994a, 1995a, 1996, 

1997, 1998b, 1999c, 2000], "Fire Accident Reports" [MSHA 

1991b,c; 1994b; 1995b,c; 1998a,c,d,e,f; 1999a,b,d,e], MSHA 

"Fire Accident Abstracts" internal publications, and verbal communications with mine personnel. Mining companies are required 

by 30 CFR 50 to report to MSHA all fires that result in injuries 

and fires that are not extinguished within 30 min of discovery. A 

small number of fires lasting <30 min without injuries reported in 

the "Fire Accident Abstracts" have been included in this report. 

The analysis in this report will provide the National Institute 

for Occupational Safety and Health (NIOSH), the Mine Safety 

and Health Administration (MSHA), and the mining industry 

with a better understanding of the causes and hazards of mine 

fires and fire injuries. It will also form a basis for developing 

future fire research programs. 

METHODOLOGIES
 

For all coal mining categories, data on coal mine fires during 

1990–1999 have been reported as actual numbers and calculated 

values. 

1. For each mining category, actual numbers include the 

total number of fires, fire injuries, employees' working hours, 

lost workdays, and coal production (for underground and 

surface mines only) for a 10-year period (1990–1999) and for 

five successive 2-year periods within the 10-year period. These 

numbers have also been reported by state (10-year period). The 

actual number of fire fatalities has been reported by time period. 

Furthermore, actual numbers of fires for the five 2-year periods 

have been reported by ignition source, method of detection and 

suppression, equipment involved, location, and burning material. Actual numbers of fire injuries per number of fires causing injuries and total fires have been reported by year, ignition 

source, equipment involved, and location. 

2. For each mining category, the calculated values include 

the fire and injury risk rates during the 10-year period and the 

five 2-year periods. The fire risk rate (Frr) values were 

calculated according to the USBM formula [Pomroy and 

Carigiet 1995]. The injury risk rate (Irr) values were calculated 

according to the MSHA formula [MSHA 1991a, 1992, 1993, 

1994a, 1995a, 1996, 1997, 1998b, 1999c, 2000]. Also, risk rate 

values for individual states (10-year period) were calculated 

according to the above-mentioned formulas. 

Of note is that only the risk rate values for the 10-year and 

five 2-year periods and risk rate values for individual states with 

the highest number of fires and fire injuries were considered for 

comparison purposes. The fatality risk rate values were not 

calculated because of the extremely small number of fire 

fatalities during the 10-year period. 

3. Calculations of risk rate values are as follows: 

a.	 Fire risk rate (Frr) value: Number of fires per million 

tons of coal produced [Pomroy and Carigiet 1995]. 

b. Injury risk rate (Irr) value: Number of fire injuries multiplied by 200,000 working hours per total employees' 

working hours [MSHA 1991a, 1992, 1993, 1994a, 1995a, 

1996, 1997, 1998b, 1999c, 2000]. The Irr value is the 

average risk rate value for the number of fire injuries per 

200,000 working hours for a given time period. 
3 

c.	 Total employees' working hours (Ewhr) value during 

1990–1999: Sum of 10 yearly Ewhr values for all of the 

states involved in fires. This value also includes the 

Ewhr value reported for all other states not involved in 

fires. The Ewhr value for each state (10-year time 

period) is the sum of 10 yearly Ewhr values for that state. 

d. Total employees' working hours (Ewhr) value for five 2­

year time periods: Sum of two yearly Ewhr values for all 

of the states, involved and not involved in fires, within 

the 2-year period. 

e.	 The coal production (CP) values in short tons were calculated similarly. 

f.	 The lost workday (LWD) values were reported by state 

and time period. 

g. An LWD value of 6,000, assigned by MSHA to each 

fatality, was reported. 

FIRE DATA ANALYSIS FOR ALL COAL MINING CATEGORIES
 

UNDERGROUND COAL MINE FIRES 

Table 1 and figure 1 show the number of fires and fire injuries that occurred in underground coal mines by state during 

1990–1999. Table 1 also shows by state the risk rates, employees' working hours, lost workdays, and coal production. 

Table 1.—Number of fires, fire injuries, and risk rates for underground coal mines by state, 

employees' working hours, lost workdays, and coal production, 1990–1999 

State1 No. fires1 1 No. injuries LWD2 Ewhr,2

 106 hr CP,2 106 st 3 Frr Irr3 

Alabama .......... 

Colorado . . . . . . . . . . 

Illinois . . . . . . . . . . . . 

Indiana . . . . . . . . . . . 

Kentucky . . . . . . . . . . 

Ohio . . . . . . . . . . . . . 

Pennsylvania ...... 

Tennessee ........ 

Utah . . . . . . . . . . . . . 

Virginia . . . . . . . . . . . 

West Virginia . . . . . . 

Wyoming . . . . . . . . . . 

All other states . . . . . 

 Total . . . . . . . . . . . 

12 

7 

12 

1 

12 

1 

12 

2 

1 

15 

9 

3 

— 

87 

4 

1 

1 

1 

6 

— 

9 

— 

— 

7 

5 

— 

— 

34 

6 

4 

6 

— 

1 

— 

14 

— 

— 

140 

37 

— 

— 

208 

67 

20 

96 

5 

245 

32 

116 

9 

34 

96 

271 

3 

9 

1,003 

165 

148 

403 

24 

948 

133 

456 

21 

252 

291 

1,131 

23 

13 

4,008 

0.073 

0.047 

0.03 

0.042 

0.013 

0.0075 

0.026 

0.095 

0.004 

0.052 

0.008 

0.13 

— 3

0.022 

0.012 

0.01 

0.002 

0.04 

0.005 

— 

0.016 

— 

— 

0.015 

0.004 

— 

—3

0.007 

1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to USBM and MSHA formulas reported in the "Methodologies" section.
 

 Overall, 87 fires occurred in 12 states. Twenty-seven of those fires 

caused 34 injuries (the yearly average was 8.7 fires and 

3.4 injuries). One fire and one injury involved a contractor. 

The underground mine fires required 25 mine rescue team 

interventions and 30 mine/section evacuations followed by 

13 mine/section sealing/flooding/CO2/N2 gas injections. The 

Ewhr value was 1,003 × 106

 hr (Irr = 0.007), the CP value was 

4,008 × 106

 st (Frr = 0.022), and the LWD value was 208. 

Virginia had the most fires (15 fires and 7 injuries). Pennsylvania had the most fire injuries (12 fires and 9 injuries), followed by Kentucky (12 fires and 6 injuries), and Alabama 

(12 fires and 4 injuries). Among these states, Alabama had the 

highest fire risk rate value (Frr = 0.073), whereas Pennsylvania 

had the highest injury risk rate value (Irr = 0.016). 

Table 2, partly illustrated in figure 2, shows by time period 

the number of fires, fire injuries, risk rates, employees' working 

hours, lost workdays, and coal production. The number of fires 

and fire injuries show a decrease followed by an increase during 

the five time periods (see table 2 and figure 2). This was accompanied by a decline in employees' working hours throughout 

the periods and an overall small decrease in coal production. 

The Irr and Frr values follow patterns similar to those shown by 

the fire and injury values. 

By comparison, data from Pomroy and Carigiet [1995] show 

that during 1978–1992 a total of 11 states were involved in 164 

underground coal mine fires (yearly average, 10.8) with 43 injuries 

(yearly average, 2.9) and 27 fatalities (yearly average, 2; however, 

the 27 deaths occurred during a single fire caused by an overheated 

air compressor [MSHA 1984]). The CP value was 5,340 × 106

 st 

(yearly average, 356 × 106

 st) (Frr = 0.031). Data on employees' 

working hours and injury risk rates were not available. 

Tables 3–8 show the number of fires by ignition source, 

method of detection and suppression, equipment involved, 

location, and burning material by time period. Figure 3 shows 

the major variables during 1990–1999. Table 9 shows the 

number of fire injuries per number of fires causing injuries and 

total fires by year, ignition source, equipment involved, and 

location. 
4 

Figure 1.—Number of fires and fire injuries for underground coal mines by state, 1990–1999. 

Figure 2.—Number of fires, fire injuries, risk rates, and coal production for underground coal mines by time period and employees' 

working hours, 1990–1999. 
5 

Table 2.—Number of fires, fire injuries, and risk rates for underground coal mines by time period, 

employees' working hours, lost workdays, and coal production. 1990–1999 

90-91 

Time period 

92-93 94-95 96-97 98-99 90-99 

Number of fires1 ....... 25 18 23 6 15 
 87 

Number of fire injuries1 . . 17 5 7 1 4 34

LWD2 ............... 121 45 12 8 22 
 208 

Ewhr,2

 106 hr . . . . . . . . . . 257 209 196 179 162 
 1,003 

CP,2

 106 st . . . . . . . . . . . 824 752 792 830 810 
 4,008 

Frr3 ................. 0.03 0.024 0.03 0.007 0.019 
 3

0.022 

Irr3 .................. 0.013 0.005 0.007 0.001 0.005 
 3

0.007 1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to USBM and MSHA formulas reported in the "Methodologies" section.
 

Table 3.—Number of fires for underground coal mines by ignition source and time period, 1990–1999 

Ignition source 

Time period
 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99
 

No. fires
 

90-99 

No. fires 

Flame cutting/welding spark/slag/flame1 .......... 
 8 2 3 2 2 17

Spontaneous combustion2 ..................... 
 4 2 4 3 2 15

Electrical short/arcing/explosion3 ................ 
 5 7 9 1 6 28

Conveyor belt friction . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 5 5 — 4 15 

Heat source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — — 1 — — 1 

Overheated oil/grease ........................ 
 2 — — — — 2 

Mechanical malfunction/friction ................. 
 3 1 1 — — 5 

Flammable liquid/refueling fuel on hot surfaces . . . . . 
 1 — — — — 1 

Hydraulic fluid/fuel on equipment hot surfaces ...... 
 — 1 — — — 1 

Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — 1 2

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 25 18 23 6 15 87 

 1

This source usually caused fires involving welders' clothing or oxyfuel/grease. However, in one instance sparks/hot 

slag/flames caused a methane ignition followed by a large fire requiring firefighting intervention and mine/section 

evacuation and sealing. In another instance, undetected hot slag caused a large fire requiring firefighting intervention 

and mine evacuation and sealing, followed by a methane explosion.

 2

This source at least twice was accompanied by methane explosions.

 3

This source caused 12 mobile equipment fires. 

Table 4.—Number of fires for underground coal mines by method of detection and time period, 1990–1999 

Method of detection 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Visual method:

 Flames/flash fires . . . . . . . . . . . . . . . . . . . . . . 2 1 3 — — 6

 Sparks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 3 1 2 15

 Smoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4 2 — 1 10

 Late smoke detection . . . . . . . . . . . . . . . . . . . 7 9 12 2 6 36 

CO/H2 gas sampling . . . . . . . . . . . . . . . . . . . . . . 1 1 2 2 1 7 

Touched hot spots ....................... 1 — — — 1 2 

CO/smoke belt detection system . . . . . . . . . . . . — — 1 — — 1 

Mine-wide monitoring system . . . . . . . . . . . . . . . — — — — 1 1 

Undetected ............................. 1 — — — 1 2 

Explosion1 .............................. 3 1 — 1 1 6 

Power loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — — — 1 1

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18 23 6 15 87 1

Includes methane ignition, electrical cable, and starter box explosions. 
6 

Table 5.—Number of fires for underground coal mines by suppression method and time period, 1990–1999 

Suppression method 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Mine/section sealing/flooding/CO2/N2 gas injections . . . 3 
 2 3 2 3 13

Portable fire extinguisher ........................ 
 4 6 5 1 1 17

Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 6 2 8 1 3 20

Manual/FE1 ................................... 
 7 1 1 — 2 11 

FE-dry chemical powder/rock dust/water2 ........... 
 2 6 5 1 3 17

Machine water spray . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 2 — — — — 2 

FSS-dry chemical powder-water . . . . . . . . . . . . . . . . . . 
 — 1 1 — 1 3 

Destroyed/heavily damaged3 ..................... 
 1 — — 1 2 4

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 25 18 23 6 15 87 

FE Portable fire extinguisher.
 

FSS Machine fire suppression system.
 1

Methods used by welders to extinguish clothing or oxyfuel/grease fires. 2

In two instances, foam was also used.
 3

Due to failure of other firefighting methods, late fire detection, or undetected fires.
 

Table 6.—Number of fires for underground coal mines by equipment involved and time period, 1990–1999 

Equipment 

Time period 

90-91 92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Oxyfuel torch . . . . . . . . . . . . . . . . . . . . . . 8 2 4 2 2 18 

Beltline/drive/pulley/feeder ............ 3 4 5 — 4 16 

Electrical system/cable/starter/breaker/

 transformer/rectifier/voltage box ...... 4 4 2 — 3 13 

Generator/pump/fan ................. 1 1 1 — — 3 

Mobile equipment1 .................. 4 5 7 1 4 21 

Other2 ............................ 5 2 4 3 2 16

 Total .......................... 
 25 18 23 6 15 87 

 1

Includes scoops, bolters, continuous miners, shearers, ore cart, shuttle cars, 3-wheelers, jeeps, railrunners, trolleys, 

locomotives, and power scalers.

 2

Includes nonequipment (mostly coal piles). 

Table 7.—Number of fires for underground coal mines by location and time period, 1990–1999 

Location 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Flame cutting/welding areas1 ................... 
 6 2 3 2 2 15 

Gobline/sealed/abandoned/coal pit areas ......... 
 3 2 3 1 1 10 

Belt entry/feeder/slope/portal branch areas ........ 
 6 5 7 — 6 24 

Longwall panel/headgate/main return ............ 
 2 — 1 3 1 7 

Haulage/track rails . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 2 1 — — — 3 

Power station/rectifier areas . . . . . . . . . . . . . . . . . . . . 
 — 1 — — 1 2 

Generator/transformer/fan/breaker/pump areas ..... 
 1 2 2 — 1 6 

Charging station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — — 3 — — 3 

Mining face/intersection/crosscut areas ........... 
 4 — 3 — — 7 

Maintenance areas ........................... 
 1 1 1 — — 3 

Mobile equipment working areas2 ................ 
 — 4 — — 3 7

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 25 18 23 6 15 87 

 1

Includes belt entry, feeder, drive and pulley areas, shops, elevator shafts, overcasts, longwall face/headgate, and mobile 

equipment maintenance areas.

 2

Includes haulage, bolting, and transportation areas. 
7 

Table 8.—Number of fires for underground coal mines by burning material and time period, 1990–1999 

Burning material 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Coal/coal dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 6 3 1 16 

Electrical cables/wires/starter/voltage box/rectifier/

 electrical insulation/breaker/transformer/batteries . . . . 
 5 7 7 1 6 26 

Belt/feeder/drive/pulley .......................... 
 3 2 4 — 4 13 

Oxyfuel/grease/clothing . . . . . . . . . . . . . . . . . . . . . . . . . 
 7 2 2 1 1 13 

Elevator shaft/motor ............................ 
 1 3 2 — — 6 

Flammable liquids/refueling fuel/methane ........... 
 1 1 1 1 2 6 

Hydraulic fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — 1 1 — — 2 

Gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — 1 2 

Oil/resin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 3 — — — — 3

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 25 18 23 6 15 87 

Table 9.—Number of fire injuries per number of fires causing injuries and total fires in underground coal mines by year, ignition source, 

equipment involved, and location, 1990–1999 

Year 

No. fires 

causing 

injuries 

No. 

total 

fires 

No. 

fire 

injuries 

Ignition source Equipment Location 

1990 

1991 

1992 

1993 

1994 

1995 

1996 

1997 

1998 

1999 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

2 

2 

1 

4 

1 

1 

2 

2 

1 

2 

1 

1 

1 

1 

— 

1 

— 

1 

1 

1 

1 

16 

— 

9 

— 

— 

— 

14 

4 

11 

— 

— 

12 

— 

— 

3 

3 

5 

10 

— 

— 

— 

8 

2 

1 

4 

1 

1 

3 

2 

1 

2 

1 

1 

1 

1 

— 

1 

— 

1 

1 

1 

1 

Electrical short/arcing/battery explosion . . . Electrical cables/starter/

 voltage box/battery. 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch . . . . . . . . . . . . . . . . . . 

Refueling fuel on hot surfaces ......... Mobile equipment2 .............. 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch . . . . . . . . . . . . . . . . . . 

Electrical short/arcing . . . . . . . . . . . . . . . . Pump unit . . . . . . . . . . . . . . . . . . . . . 

Conveyor belt friction . . . . . . . . . . . . . . . . Beltline/pulley . . . . . . . . . . . . . . . . . . 

Electrical short/arcing ................ Power cables/mobile equipment2 . . . 

Electrical short/arcing ................ Power breaker/mobile equipment2 . . 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch .................. 

Electrical short/arcing . . . . . . . . . . . . . . . . Power cable/mobile equipment2 .... 

Conveyor belt friction . . . . . . . . . . . . . . . . Beltline/drive/pulley . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch .................. 

Heat source . . . . . . . . . . . . . . . . . . . . . . . Heater . . . . . . . . . . . . . . . . . . . . . . . . 

Conveyor belt friction . . . . . . . . . . . . . . . . Coal feeder/motor ............... 

— — 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch .................. 

Conveyor belt friction . . . . . . . . . . . . . . . . Beltline/drive pulley . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame . . Oxyfuel torch . . . . . . . . . . . . . . . . . . 

Hot surface . . . . . . . . . . . . . . . . . . . . . . . . Mobile equipment2 .............. 

Electrical short/arcing . . . . . . . . . . . . . . . . Electrical power cables . . . . . . . . . . . 

Loading track/charging station. 

Flame cutting/welding areas.1 

Maintenance areas. 

Flame cutting/welding areas.1 

Pump station. 

Belt entry. 

Trolley track rails/

 transportation

 areas. 

Pump station/bolting

 areas. 

Flame cutting/welding areas.1 

Charging station/

 mining areas. 

Belt entry. 

Flame cutting/welding areas.1 

Mining intersection. 

Belt entry. 

— 

Flame cutting/welding areas.1 

— 

Belt entry. 

Flame cutting/welding areas.1 

Maintenance areas. 

Power station. 

Total . . 27 87 34 1

Includes beltlines, longwall mining face, and mobile equipment maintenance areas. 2

Includes bolters, scoops, jeeps, trolley, railrunners, and shuttle cars. 
8 

Figure 3.—Major variables for underground coal mine fires, 1990–1999. (FE = portable fire extinguisher) 

Ignition Source 

The number of fires and fire injuries by ignition source and 

time period is shown in tables 3 and 9. Electrical short/arcing 

caused the most fires (28 fires or 32% with 17 injuries). These 

occurred in electrical power and cable systems, power circuits and 

breakers, belt transformers, grounded cables and wires, batteries, 

high-voltage boxes, power generators, and rectifiers. The fires 

involved beltlines, drives, and pulleys; power centers and power 

units; and mobile equipment. Twelve mobile equipment electrical 

fires became large fires (at times involving the hydraulic lines) 

that required firefighting interventions and mine/section

evacuations. 

Another ignition source was flame cutting/welding spark/ 

slag/flames (18 fires or 21% with 10 injuries). This source 

caused fires usually involving welders' clothing or oxyfuel/ 

grease (grease embedded in the equipment's mechanical components). However, in at least one instance sparks/hot slag/ 

flames caused a methane ignition followed by a large fire, which 

required firefighting intervention and mine/section evacuation 

and sealing. In another instance, undetected hot slag caused a 

large fire, which required firefighting intervention and mine 

evacuation and sealing followed by a methane explosion. 

Friction of conveyor belts against pulleys, drives, rollers, 

idlers, and bearings resulted in 16 fires (18%) with 4 injuries. 

This source, usually detected long after the fire had started, 

caused extensive damage to beltlines, drives, and pulleys and 

disruption of mining operations. 

Spontaneous combustion of coal resulted in 15 fires (17%). 

This source, usually detected long after the fire had started, caused 

fires involving goblines and sealed and abandoned areas, which 

severely disrupted mining operations. In at least two instances the 

spontaneous combustion fires were accompanied by methane 

explosions and required mine rescue team interventions and 

mine/section evacuations. 

Other ignition sources were flammable liquid/refueling fuel 

on hot surfaces (four fires), mechanical malfunction/friction 

(two fires), overheated oil/grease (two fires), heat source (one 

fire), and hydraulic fluid sprayed onto mobile equipment hot 

surfaces (one fire). The latter fire grew out of control and required mine rescue team intervention. 

During the first period (1990–1991), the largest number of 

fires were caused by the flame cutting welding spark/slag/flame 

source. During the second, third, and fifth periods, the largest 

number of fires were caused by the electrical short/arcing/ 

explosion source. During the fourth period, the largest number 

of fires were caused by spontaneous combustion (see table 3). 

By comparison, data from Pomroy and Carigiet [1995] for 

1978–1992 show that the leading ignition sources in underground coal mine fires were electrical short/arcing, belt friction, 

flame cutting/welding spark/slag, and spontaneous combustion. 

Method of Detection 

Table 4 shows the number of fires by method of detection 

and time period. The most frequent methods were miners who 

saw smoke long after the fire had started, followed by welders 

who saw sparks and miners who saw smoke shortly after the 

fires had started. Other methods of detection were operators 

who saw the fires when they started as flames/flash fires, miners 

who heard an explosion or touched hot spots, and operators who 

experienced power loss. Nine fires were detected by CO/H2 gas 

sampling, CO/smoke belt fire detection systems, or mine-wide 

monitoring systems. Two fires were undetected. 
9 

During the first period, the largest number of fires were detected by sparks and detected late by smoke. During the second, 

third, and fifth periods, the largest number of fires were detected 

late by smoke. During the fourth period, the largest number of 

fires were detected late by smoke and by CO/H2 gas sampling (see 

table 4). By comparison, data from Pomroy and Carigiet [1995] 

for 1978–1992 show that the most frequent methods of detection 

for underground coal mine fires were miners who saw the fires 

when they started or saw smoke shortly after they had started. 

Suppression Method 

Table 5 shows the number of fires by suppression method 

and time period. Usually more than one agent was used to fight 

a fire. The most common methods were water or portable fire 

extinguishers alone and portable fire extinguishers with dry 

chemical powder, rock dust, and water. In two instances, foam 

was also used. In 13 instances, mine/section sealing/flooding/ 

CO2/N2 gas injections were required. Other methods included 

manual techniques with or without portable fire extinguishers 

(welders' methods to extinguish clothing or oxyfuel/grease fires) 

and machine water sprays. 

Of note is that portable fire extinguishers alone, although 

used upon discovery of the fires, were successful in extinguishing only small fires involving grease, flammable liquids, power 

units, engine/mechanical malfunctions, oxyfuel/grease, and 

overheated oil. Three pieces of mobile equipment involved in 

fires had machine fire suppression systems. Dual activation 

(two activations) of machine fire suppression and motor deenergization systems was successful in temporarily abating the 

fires. However, the flames reignited, fueled by the flow of pressurized fluids entrapped in the lines (not affected by the motor 

deenergization operation). 

Twelve of the mobile equipment electrical fires (which in at 

least one instance affected the hydraulic lines) and one hydraulic 

fluid fire became large fires because of unavailability of effective machine fire suppression systems, lack of an emergency 

line drainage system, or lack of effective and rapid local 

firefighting response capabilities. Mine rescue teams (required 

for 25 of the fires), upon mine/section evacuation (required 

30 times), fought the mobile equipment fires (5 times) and other 

large fires with dry chemical powder, rock dust, and water. In 

all, five fires destroyed or heavily damaged equipment 

(including two pieces of mobile equipment) because of failure 

of other firefighting methods, late fire detection, undetected 

fires, or fire size. 

Other factors that determined the success of fire-suppressing 

agents were the time that elapsed between detection and application of agents and effective and rapid local firefighting 

response capabilities. 

During the first period, the largest number of fires were 

suppressed manually with or without portable fire extinguishers 

or by water alone. During the second period, the largest number 

of fires were suppressed with portable fire extinguishers, dry 

chemical powder, rock dust and water or with portable fire 

extinguishers alone. During the third period, the largest number 

of fires were suppressed with water alone. During the fourth 

period, the largest number of fires were extinguished by mine/ 

section sealing/flooding/CO2/N2 gas injections. During the fifth 

period, the largest number of fires were extinguished by mine/ 

section sealing/flooding/CO2/N2 gas injections; by dry chemical, 

rock dust, and water; or by water alone (see table 5). By comparison, data from Pomroy and Carigiet [1995] for 1978–1992 

show that the most common suppression methods used in 

underground coal mine fires were water, dry chemical powder, 

rock dust, and sealing with CO2/N2 gas injections. 

Equipment Involved 

Table 6 shows the number of fires by equipment involved 

and time period. The equipment most often involved was mobile equipment (e.g., scoops, shuttle cars, bolters, railrunners, 

continuous miners, trolleys, ore carts, jeeps, locomotives, 

shearers, three-wheelers, and power scalers). This was followed 

by oxyfuel torches; beltlines, pulleys, drives, and feeders; and 

electrical systems, cables, breakers, starters, rectifiers, voltage 

boxes, and transformers. Other equipment included pumps, generators, and ventilation fans. Sixteen fires did not involve 

equipment (mostly coal piles). 

During the first and fourth periods, the largest number of 

fires involved oxyfuel torches. During the second and third 

periods, the largest number of fires involved mobile equipment. 

During the fifth period, the largest number of fires involved 

mobile equipment and beltlines, drives, pulleys, and feeders (see 

table 6). By comparison, data from Pomroy and Carigiet [1995] 

for 1978–1992 show that the equipment most often involved in 

underground coal mine fires were beltlines and drives, followed 

by flame cutting/welding equipment. 

Location 

Table 7 shows the number of fires by location and time period. 

Figure 3 shows the major fire locations during 1990–1999. The 

most common locations were belt entry, feeder, slope and portal 

branch areas, flame cutting/welding areas (at the longwall face 

and headgate, belt entries, feeders, shops, elevator shafts, 

overcasts, and mobile equipment maintenance areas), and 

goblines, sealed, abandoned, and coal pit areas. Other fire 

locations were the mining face, intersection, and crosscut areas; 

the longwall panel/headgate and main return areas; and mobile 

equipment working areas (haulage, bolting, and transportation 

areas). Generator and pump housing, belt transformer, fan and 

breaker areas, haulage and track rail areas, rectifier, charging and 

power stations, and maintenance areas were other locations 

affected by fires. 

During the first period, the largest number of fires occurred 

at flame cutting/welding areas and at belt entry, feeder, portal 

branch, and slope areas. During the second, third, and fifth 

periods, the largest number of fires occurred at belt entry, slope, 

feeder, and portal branch areas. During the fourth period, the 

largest number of fires occurred at longwall panel, headgate, 

and main return areas (see table 7). By comparison, data from 

Pomroy and Carigiet [1995] for 1978–1992 show that the most 

common fire locations in underground coal mines were belt 

entry, working face, intake entry, and track haulage areas. 
10 

Burning Materials 

Table 8 shows the number of fires by burning material and 

time period. The materials most often involved were electrical 

cables, starters, voltage boxes, rectifiers, electrical insulation, 

breakers, transformers, and batteries. These were followed by 

coal and coal dust; belts, feeders, drives, and pulleys; and oxyfuel, grease, and clothing. Other burning materials were flammable liquids, methane, elevator shafts and motors, oil and 

resin, hydraulic fluids, and gearboxes. 

During the first period, the largest number of fires involved 

oxyfuel, grease, and clothing materials. During the second, 

third, and fifth periods, the largest number of fires involved 

electrical cables, wires, starters, voltage boxes, transformers, 

starters, and batteries. During the fourth period, the largest 

number of fires involved coal and coal dust (see table 8). By 

comparison, data from Pomroy and Carigiet [1995] for 

1978–1992 show that the most frequent burning materials in 

underground coal mines were coal and coal dust, electrical 

insulation, oil and grease, conveyor belts and rollers, wood, 

rubber hoses, and tires. 

Fire Injuries 

Table 9 shows the number of fire injuries per number of fires 

causing injuries and total fires by year, ignition source, 

equipment involved, and location during 1990–1999. Overall, 

there were 34 injuries caused by 27 fires. The greatest number 

of fire injuries occurred in 1990 (10 injuries caused by 4 fires) 

and 1991 (7 injuries caused by 7 fires). The ignition sources 

that caused most of the fire injuries were electrical short/arcing, 

battery explosion, and flame cutting/welding spark/slag/flames. 

Other ignition sources were conveyor belt friction, heat source, 

and refueling fuel on hot surfaces. The equipment most often 

involved in fire injuries were electrical power cables, voltage 

boxes, oxyfuel torches, beltlines, drives, pulleys and feeders, 

and mobile equipment. The most common locations for fire injuries were pump, power and charging stations, mobile equipment working areas, flame cutting/welding areas, trolley track 

rails and transportation areas, and belt entries. 

By comparison, data from Pomroy and Carigiet [1995] for 

1978–1992 show that the ignition sources causing the most of 

the fire injuries were electrical short/arcing, belt friction, and 

flame cutting/welding sources. The equipment most often involved in fire injuries and fire fatalities included air compressors 

(which caused 27 fatalities during one fire), trolley power 

cables, and oxyfuel torches. The most common locations for 

fire injuries were main intakes, belt entries, longwall headgate, 

working faces, and track entries. 

SURFACE OF UNDERGROUND COAL MINE FIRES 

Table 10 and figure 4 show the number of fires and fire 

injuries occurring at the surface of underground coal mines by 

state during 1990–1999. Table 10 also shows by state the risk 

rate, employees' working hours, and lost workdays. 

A total of 65 fires occurred in 10 states. Thirteen of those fires 

caused 12 injuries and 1 fatality (the yearly average was 6.5 fires 

and 1.2 injuries). Four fires and one fire injury involved contractors. The Ewhr value was 97 × 106

 hr (Irr = 0.025); the LWD 

value was 6,206. Pennsylvania had the most fires (20 fires and 

5 injuries), followed by West Virginia (16 fires and 1 fatality) and 

Kentucky (15 fires and 3 injuries). Among these states, Pennsylvania had the highest injury risk rate value (Irr = 0.095). 

Table 11, partly illustrated in figure 5, shows by time period 

the number of fires, fire injuries, and fire fatalities; risk rates; 

employees' working hours; and lost workdays. The number of 

fires and fire injuries show a decrease followed by an increase 

during the five time periods, accompanied by a decline in 

employees' working hours throughout the periods (see table 11 

and figure 5). The Irr values follow patterns similar to those 

shown by the injury values. 

Tables 12–17 show the number of fires by ignition source, 

method of detection and suppression, equipment involved, 

location, and burning material by time period. Figure 6 shows the 

major variables during 1990–1999. Table 18 shows the number 

of fire injuries per number of fires causing injuries and total fires 

by year, ignition source, equipment involved, and location. 

Ignition Source 

The number of fires and fire injuries by ignition source and 

time period is shown in tables 12 and 18. The leading sources 

were hydraulic fluid/fuel sprayed onto equipment hot surfaces 

(11 fires or 17% with 1 injury), spontaneous combustion/hot 

coal (11 fires or 17%), and flame cutting/welding spark/slag/ 

flames (11 fires or 17% with 7 injuries). Three of the mobile 

equipment hydraulic fluid/fuel fires became large fires, which 

at times required fire department interventions. In at least two 

instances flames erupted in the cab, probably because of the 

ignition of flammable vapors and mists that penetrated the cab. 

Of note is that most of the hydraulic fluid/fuel fires were caused 

when hydraulic fluids sprayed onto equipment hot surfaces; 

subsequently, these fires involved the fuel lines. The flame 

cutting/welding spark/slag/flame source caused fires usually 

involving welders' clothing or oxyfuel/grease (grease embedded 

in the equipment's mechanical components). However, in one 

instance sparks/hot slag/flames caused a methane ignition followed by a large fire, and twice undetected hot slag caused coal 

belt fires. Other ignition sources were heat source (four fires), 

electrical short/arcing (four fires), conveyor belt friction (three 

fires), and overheated oil (one fire). Twenty ignition sources 

(mostly affecting facilities) were unknown. 

During the first period, the largest number of fires were 

caused by hydraulic fluid/fuel sprayed onto equipment hot 

surfaces. During the second period, the largest number of fires 

were caused by spontaneous combustion/hot coal. During the 

third and fourth periods, the largest number of fires were caused 

by the flame cutting/welding spark/slag/flame source. During 

the fifth period, the largest number of fires were caused by 

flame cutting/welding spark/slag/flames, spontaneous 

combustion/hot coal, and hydraulic fluid/fuel sprayed onto 

equipment hot surfaces (see table 12). 
11 

Figure 4.—Number of fires and fire injuries for surface of underground coal mines by state, 1990–1999. 

Figure 5.—Number of fires, fire injuries, and risk rates for surface of underground coal mines by time period and employee’ working 

hours, 1990–1999. 
12 

Figure 6.—Major variables for surface of underground coal mine fires, 1990–1999. (FE = portable fire extinguisher) 

Table 10.—Number of fires, fire injuries, and risk rates for surface of underground coal mines by state, 

employees' working hours, and lost workdays, 1990–1999 

State1 No. fires1 1 No. injuries LWD2 Ewhr,2

 106 hr Irr3 

Alabama ................... 

Colorado . . . . . . . . . . . . . . . . . . . 

Illinois . . . . . . . . . . . . . . . . . . . . . 

Kentucky . . . . . . . . . . . . . . . . . . . 

Montana . . . . . . . . . . . . . . . . . . . 

Ohio . . . . . . . . . . . . . . . . . . . . . . 

Pennsylvania ............... 

Utah . . . . . . . . . . . . . . . . . . . . . . 

Virginia . . . . . . . . . . . . . . . . . . . . 

West Virginia4 ............... 

Other states . . . . . . . . . . . . . . . . 

 Total . . . . . . . . . . . . . . . . . . . . 

4 

3 

1 

15 

1 

1 

20 

2 

2 

16 

— 

65 

1 

1 

1 

3 

— 

— 

5 

1 

— 

— 

— 

12 

4 

— 

42 

88 

— 

— 

24 

6 

42 

6000 

— 

6206 

5.8 

3.6 

6 

23 

0.12 

3.7 

10.5 

4 

11 

20.4 

8.8 

97 

0.035 

0.056 

0.033 

0.026 

— 

— 

0.095 

0.05 

— 

— 

30.025 —

1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to MSHA formula reported in the "Methodologies" section. 4

West Virginia had 1 fire fatality.
 

Table 11.—Number of fires, fire injuries, fire fatalities, and risk rates for surface of underground coal mines 

by time period, employees' working hours, and lost workdays, 1990–1999 

90-91 

Time period 

92-93 94-95 96-97 98-99 90-99 

Number of fires1 ............. 17 14 16 7 11 
 65 

Number of fire injuries1 ........ 3 1 5 1 2
 12

Number of fire fatalities . . . . . . . 1 — — — —
 1 

LWD2 ..................... 6000 24 88 10 84
 6206 

Ewhr,2

 106 hr . . . . . . . . . . . . . . . . 

Irr3 ........................ 

27 

0.023 

21 

0.01 

18 

0.056 

16 

0.0125 

15 
 

0.028
 

97 30.025 

1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to MSHA formula reported in the "Methodologies" section.
 
Table 12.—Number of fires for surface of underground coal mines by ignition source and time period, 1990–1999 

Ignition source 

Time period 

90-91 92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Heat source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 1 2 — — 4 

Flame cutting/welding spark/slag/flame1 .......... 
 2 1 4 2 2 11

Electrical short/arcing . . . . . . . . . . . . . . . . . . . . . . . . . 
 3 — — — 1 4 

Spontaneous combustion/hot coal ............... 
 2 3 3 1 2 11

Conveyor belt friction . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 1 — 1 — 3 

Hydraulic fluid/fuel on equipment hot surfaces ...... 
 4 2 3 — 2 11 

Overheated oil .............................. 
 1 — — — — 1 

Unknown/other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 3 6 4 3 4 20

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 17 14 16 7 11 65 

 1

This source caused fires usually involving welders' clothing or oxyfuel/grease. However, in one instance undetected hot

slag caused a methane ignition followed by a large fire, and twice undetected hot slag caused coal belt fires. 

13 

Table 13.—Number of fires for surface of underground coal mines by method of detection

and time period, 1990–1999 

Method of detection 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Visual method:

 Flames/flash fires . . . . . . . . . . 2 2 3 — 2 
 9

 Sparks . . . . . . . . . . . . . . . . . . 2 — — 1 2 
 5

 Late smoke detection . . . . . . . 6 3 4 2 3 
 18

 Smoke . . . . . . . . . . . . . . . . . . 2 1 3 1 — 
 7

 Smoldering . . . . . . . . . . . . . . . 1 1 — — — 
 2 

Smelled smoke . . . . . . . . . . . . . . — 1 — — — 
 1 

Explosion . . . . . . . . . . . . . . . . . . 1 — 2 — — 
 3 

Undetected ................. 3 6 4 3 4
 20

 Total . . . . . . . . . . . . . . . . . . . 17 14 16 7 11 
 65 

Table 14.—Number of fires for surface of underground coal mines by suppression method 

and time period, 1990–1999 

Suppression method 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Manual/FE1 ........................... 
 3 — 3 — 2 8 

FE-foam/dry chemical powder/water . . . . . . . 
 6 6 7 3 3 25 

Coal spread-water-compaction-removal2 .... 
 2 — 1 1 2 6 

Destroyed/heavily damaged3 ............. 
 3 6 4 3 4 20 

Portable fire extinguisher ................ 
 3 — — — — 3 

FE-FSS-dry chemical powder . . . . . . . . . . . . . 
 — 1 1 — — 2 

Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — 1 — — — 1

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 17 14 16 7 11 65 

FE Portable fire extinguisher.
 

FSS Machine fire suppression system.
 1

Methods used by welders to extinguish clothing or oxyfuel/grease fires. 2

Methods used to extinguish spontaneous combustion/hot coal fires. 3

Due to failure of other firefighting methods, late fire detection, or undetected fires.
 

Table 15.—Number of fires for surface of underground coal mines by equipment involved 

and time period, 1990–1999 

Equipment 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Oxyfuel torch . . . . . . . . . . . . . . . . . . . 
 2 1 3 2 2 10 

Beltline/drive/pulley . . . . . . . . . . . . . . 
 2 1 1 1 — 5 

Heater/maintenance equipment ..... 
 2 1 2 — — 5 

Electrical power unit/system . . . . . . . . 
 1 — — — 1 2 

Pump . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — — 1 

Facilities ....................... 
 2 5 4 3 4 18 

Mobile equipment1 ............... 
 6 2 3 — 2 13 

Other2 ......................... 
 1 4 3 1 2 11

 Total . . . . . . . . . . . . . . . . . . . . . . . . 
 17 14 16 7 11 65 1

Includes hoists, loaders, dozers, scrapers, trucks, highlifts, excavators, and tractors.

2

Includes nonequipment (mostly coal piles). 
14 

Table 16.—Number of fires for surface of underground coal mines by location

and time period, 1990–1999 

Location 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Flame cutting/welding areas1 ......... 
 2 — 4 1 2 9 

Coal silo/stock/refuse pile . . . . . . . . . . . . 
 1 2 1 — 2 6 

Beltline/drawoff tunnel areas ......... 
 1 2 2 1 — 6 

Power station . . . . . . . . . . . . . . . . . . . . . 
 2 — — — 1 3 

Maintenance areas ................. 
 3 1 3 — — 7 

Facility areas ..................... 
 2 6 4 4 4 20

Mobile equipment working areas2 ...... 
 5 3 2 — 2 12 

Charging station . . . . . . . . . . . . . . . . . . . 
 1 — — 1 — 2

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 
 17 14 16 7 11 65 1

Includes beltline areas, storage silos, and mobile equipment maintenance areas. 2

Includes loading, hoisting, and haulage areas. 

Table 17.—Number of fires for surface of underground coal mines by burning material

and time period, 1990–1999 

Burning material 

Time period 

90-91 92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Flammable liquids . . . . . . . . . . . . . . . . . . . . . 
 1 1 2 — 2 6 

Electrical wires/systems/batteries . . . . . . . . . 
 2 — — — 1 3 

Facility/content/pump housing ............ 
 4 6 4 3 4 21 

Belt/drive/pulley . . . . . . . . . . . . . . . . . . . . . . . 
 3 2 2 1 — 8 

Coal/methane ......................... 
 1 3 3 1 2 10 

Wood ties/refuse pile/electrical insulation . . .
 1 — 1 1 — 3 

Oxyfuel/grease/clothing . . . . . . . . . . . . . . . . . 
 1 — 1 1 — 3 

Hydraulic fluid/fuel . . . . . . . . . . . . . . . . . . . . . 
 4 2 3 — 2 11

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 17 14 16 7 11 65 

Table 18.—Number of fire injuries per number of fires causing injuries and total fires at surface of underground coal mines by year, 

ignition source, equipment involved, and location, 1990–1999 

Year 

No. fires 

causing 

injuries 

No. 

total 

fires 

No. 

fire 

injuries 

Ignition source Equipment Location 

1990 

19913 

1992 

1993 

1994 

1995 

1996 

1997 

1998 

1999 

. . . 

. . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

1 

1 

2 

— 

1 

2 

2 

1 

— 

1 

2 

— 

7 

— 

10 

6 

8 

6 

10 

— 

2 

5 

5 

6 

1 

1 

1 

— 

1 

2 

2 

1 

— 

1 

2 

— 

Flame cutting/welding spark/slag/flame ........ 

Battery explosion . . . . . . . . . . . . . . . . . . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

— 

Training fire .............................. 

Flame cutting/welding spark/slag/flame ........ 

Heat source ............................. 

Flame cutting/welding spark/slag/flame . . . . . . . . 

— 

Flame cutting/welding spark/slag/flame ........ 

Flame cutting/welding spark/slag/flame ........ 

— 

1 Oxyfuel torch . . . . . . . Flame cutting/welding areas.

Mobile equipment2 . . . Charging station. 

Mobile equipment2 . . . Loadout area. 

— — 

Turnout gear . . . . . . . . Fire training area. 1 Oxyfuel torch . . . . . . . Flame cutting/welding areas.

Heater . . . . . . . . . . . . . Refuse/maintenance areas. 1 Oxyfuel torch . . . . . . . Flame cutting/welding areas.

— — 

Oxyfuel torch/mobile Maintenance areas. 

 equipment.2 

1 Oxyfuel torch . . . . . . . Flame cutting/welding areas.

— — 

Total . . . 13 65 12 1

Includes beltline, drive, and pulley areas; storage silos; shops; and mobile equipment maintenance areas.

2

Includes highlifts, loaders, and trucks.

3

During 1991, there was 1 fire fatality.
 

Method of Detection	 

Table 13 shows the number of fires by method of detection 

and time period. The most frequent method of detection was 

miners who saw smoke long after the fires had started, followed 

by operators who saw the fires when they had started as 

flames/flash fires. Other methods of detection were miners who 

saw smoke shortly after the fires had started; welders who saw 

sparks; and miners who heard an explosion, saw smoldering of 

coal, or smelled smoke. Twenty fires were undetected. The 

largest number of fires were detected late by smoke throughout 

the periods (table 13). 

Suppression Method 

Table 14 shows the number of fires by suppression method 

and time period. The most common methods were dry chemical 

powder and water, followed by manual techniques with or 

without portable fire extinguishers (welders' methods to 

extinguish clothing or oxyfuel/grease fires) and coal spread, 
15 

water, compaction, and removal (method used to extinguish spontaneous combustion/hot coal fires). Other fire suppression methods were portable fire extinguishers alone and foam and water. 

Two pieces of mobile equipment involved in fires had 

machine fire suppression systems. Dual activation (one 

activation) of machine fire suppression and engine shutoff 

systems failed to temporarily abate the flames because of the flow 

of pressurized fluids entrapped in the lines (not affected by the 

engine shutoff operation). Most of the hydraulic fluid/fuel fires 

became large fires. In at least three instances these fires required 

fire department interventions because of the continuous flow of 

fluid/fuel from the pumps due to engine shutoff failure, lack of an 

emergency hydraulic line drainage system, difficulty in activating 

available emergency systems at ground level, or lack of effective 

and rapid local firefighting response capabilities. (Fire-resistant 

hydraulic fluid is not required for equipment use at surface coal 

operations.) 

Fire brigades and fire departments (required in six instances) 

fought three mobile equipment fires and other large fires with 

foam, dry chemical powder, and water. However, 20 fires 

destroyed or heavily damaged equipment (including two pieces 

of mobile equipment) because of failure of other firefighting 

methods, late fire detection, undetected fires, or fire size. 

The largest number of fires were suppressed with portable 

fire extinguishers, foam, dry chemical powder, and water 

throughout the periods (table 14). 

Equipment Involved 

Table 15 shows the number of fires by equipment involved 

and time period. The equipment most often involved included 

mobile equipment (hoists, dozers, loaders, scrapers, trucks, 

highlifts, excavators, and tractors) and oxyfuel torches. Other 

equipment included heaters and maintenance equipment, 

beltlines, drives and pulleys, maintenance equipment, electrical 

systems, power units, and pumps. 

During the first period, the largest number of fires involved 

mobile equipment. During subsequent periods, the largest 

number of fires involved facilities (see table 15). 

Location 

Table 16 shows the number of fires by location and time 

period. The most common locations were facilities and mobile 

equipment working areas (e.g., loading, hoisting, and haulage 

areas). These were followed by flame cutting/welding areas (at 

beltline areas, storage silos, and mobile equipment maintenance 

areas) and maintenance areas. Other fire locations were coal 

silos, stock and refuse pile areas, beltline and drawoff tunnel 

areas, and power and charging stations. 

During the first period, the largest number of fires occurred at 

mobile equipment working areas. During subsequent periods, the 

largest number of fires occurred at facility areas (see table 16). 

Burning Materials 

Table 17 shows the number of fires by burning material and 

time period. The materials most often involved were pump 

housing and facilities/content, followed by hydraulic fluid/fuel, 

coal and methane, and belts, drives, and pulleys. Other burning 

materials were flammable liquids, electrical systems, wires and 

batteries, wood ties, refuse piles, electrical insulation, and 

oxyfuel/grease/clothing. During the first period, the largest 

number of fires involved hydraulic fluid/fuel and facility/content 

materials. During subsequent periods, the largest number of 

fires involved facility/content materials (see table 17). 

Fire Injuries 

Table 18 shows the number of fire injuries per number of 

fires causing injuries and total fires by year, ignition source, 

equipment involved, and location during 1990–1999. Overall, 

13 fires caused 12 injuries and 1 fatality. 

The greatest number of fire injuries occurred in 1995 

(three injuries caused by three fires). The sources that caused 

most of the fire injuries were flame cutting/welding spark/ 

slag/flames, heat sources and pressurized can explosions, and 

hydraulic fluid/fuel sprayed onto equipment hot surfaces. Other 

ignition sources were an electrical short/arcing/battery explosion 

and a source used to light a training fire. The equipment most 

often involved included oxyfuel torches, heaters, mobile 

equipment, batteries, and turnout gear. The locations where 

most of the fire injuries occurred were flame cutting/welding, 

maintenance, and mobile equipment working areas. Other fire 

locations were charging stations and fire training areas. 

The fire fatality in West Virginia in 1991 may actually have 

been caused by cardiac failure, although the victim's body was 

found among the burnt office rubble [MSHA 1991c]. 

SURFACE COAL MINE FIRES 

Table 19 and figure 7 show the number of fires and fire 

injuries for surface coal mines by state during 1990–1999. 

Table 19 also shows by state the risk rates, employees' working 

hours, lost workdays, and coal production. 

For surface coal mines, 215 fires occurred in 21 states 

during 1990–1999. Ninety-four of those fires caused 93 injuries 

and 1 fatality (the yearly average was 21.5 fires and 9.3 fire 

injuries). Fourteen fires and seven injuries involved contractors. 

The Ewhr value was 729 × 106

 hr (Irr = 0.026), the CP value 

was 6,355 × 106

 st (Frr = 0.034), and the LWD value was 8,141. 

Kentucky had the most fires and fire injuries (45 fires and 

23 injuries), followed by Pennsylvania (33 fires and 14 injuries), 

West Virginia (25 fires and 14 injuries), and Indiana (20 fires 

and 8 injuries). Among these states, Pennsylvania had the 

highest fire risk rate value (Frr = 0.145), while Kentucky had the 

highest injury risk rate value (Irr = 0.041). 
16 

Table 20, partly illustrated in figure 8, shows by time period 

the number of fires, fire injuries, fire fatalities, risk rates, 

employees' working hours, lost workdays, and coal production. 

There was a decrease in fires and fire injuries during most of the 

periods (an increase is seen only during 1994–1995), accompanied by a decline in employees' working hours throughout 

the periods and an increase in coal production during most of 

the periods. The Irr and Frr values follow patterns similar to 

those shown by the injury and fire values (see table 20 and 

figure 8). 

Tables 21–26 show the number of fires by ignition source, 

method of detection and suppression, equipment involved, 

location, and burning material by time period. Figure 9 shows the 

major variables during 1990–1999. Table 27 shows the number 

of fire injuries per number of fires causing injuries and total fires 

by year, ignition source, equipment involved, and location. 

Table 19.—Number of fires, fire injuries, and risk rates for surface coal mines by state, employees' working hours, 

lost workdays, and coal production, 1990–1999 

State1 No. fires1 1 No. injuries LWD2 Ewhr,2

 106 hr CP,2 106 st 3 Frr 
 Irr3

Alabama ............. 

Arizona . . . . . . . . . . . . . . 

Colorado . . . . . . . . . . . . . 

Illinois . . . . . . . . . . . . . . . 

Indiana . . . . . . . . . . . . . . 

Kansas . . . . . . . . . . . . . . 

Kentucky . . . . . . . . . . . . . 

Louisiana ............ 

Missouri . . . . . . . . . . . . . 

Montana4 ............ 

New Mexico . . . . . . . . . . 

Ohio . . . . . . . . . . . . . . . . 

Oklahoma ............ 

Pennsylvania ......... 

Tennessee ........... 

Texas . . . . . . . . . . . . . . . 

Utah . . . . . . . . . . . . . . . . 

Virginia . . . . . . . . . . . . . . 

Washington . . . . . . . . . . 

West Virginia . . . . . . . . . 

Wyoming . . . . . . . . . . . . . 

Other states . . . . . . . . . . 

 Total . . . . . . . . . . . . . . 

5 

3 

2 

6 

20 

1 

45 

3 

3 

4 

6 

11 

1 

33 

1 

13 

1 

6 

1 

25 

25 

— 

215 

4 

1 

— 

4 

8 

— 

23 

2 

2 

— 

1 

6 

1 

14 

1 

6 

— 

3 

— 

14 

3 

— 

93 

176 

17 

— 

44 

430 

— 

527 

— 

41 

6,000 

37 

8 

11 

501 

17 

17 

— 

79 

— 

182 

54 

— 

8,141 

24.8 

16.1 

11.6 

24.2 

53.7 

1.3 

112.1 

2.5 

4.8 

16 

30 

40.3 

6.2 

72.5 

4.6 

60.1 

0.2 

22.7 

10.4 

92.7 

62.7 

60 

729 

80 

120.7 

91 

94 

280 

3.5 

602.5 

31.8 

11.4 

392.8 

246.5 

168.1 

15.6 

228.3 

15 

529.6 

2.6 

88.4 

47 

536.6 

2,454.1 

394.5 

6,355 

0.063 

0.025 

0.022 

0.064 

0.071 

0.286 

0.075 

0.094 

0.263 

0.01 

0.034 

0.065 

0.064 

0.145 

0.067 

0.025 

0.39 

0.068 

0.021 

0.047 

0.01 

— 

3

0.034 

0.032

0.012
 

— 
 

0.033

0.03 
 

— 
 

0.041
 

0.16 
 

0.083

—
 

0.007
 

0.03
 

0.032

0.039
 

0.044

0.02
 

— 
 

0.026

— 
 

0.03
 

0.01
 

—3

0.026
 


 


 


 


 


 


 

1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to USBM and MSHA formulas reported in the "Methodologies" section. 4

Montana had one fire fatality.
 

Table 20.—Number of fires, fire injuries, fire fatalities, and risk rates for surface coal mines by time period, 

employees' working hours, lost workdays, and coal production, 1990–1999 

90-91 

Time period 

92-93 94-95 96-97 98-99 90-99 

Number of fires1 ........... 67 37 47 40 24 215 

Number of fire injuries1 ...... 32 17 19 16 9 93 

Number of fire fatalities . . . . . 1 — — — — 1 

LWD2 ................... 6,610 646 284 327 274 8,141 

Ewhr,2

 106 hr . . . . . . . . . . . . . . 177 154 143 131 124 729 

CP,2

 106 st . . . . . . . . . . . . . . . 1,180 1,176 1,267 1,325 1,408 6,355 

Frr3 ..................... 0.057 0.032 0.037 0.03 0.017 3

0.034 

Irr3 ...................... 0.036 0.022 0.026 0.024 0.015 3

0.026 1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to USBM and MSHA formulas reported in the "Methodologies" section.
 
Table 21.—Number of fires for surface coal mines by ignition source and time period, 1990–1999 

Ignition source 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Heat source 
 ................................. 5 — 2 1 2 10 

Flammable liquid/refueling fuel on hot surfaces . . . . . . 
 5 3 2 6 2 18 
 Flame cutting/welding spark/slag/flame1 ........... 20 12 14 7 6 59 

Spontaneous combustion/hot coal
 ................ 4 1 7 6 3 21 

Conveyor belt friction 
 .......................... — — 2 1 — 3 

Hydraulic fluid/fuel on equipment hot surfaces ....... 
 24 15 18 13 6 76 

Engine/mechanical malfunction/friction/explosion. .... 
 5 4 — 1 1 11 

Overheated oil
 ............................... 1 — 1 1 1 4 

Electrical short/arcing . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 2 — 3 2 8 

Natural gas explosion . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — 1 2 

Unknown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — 1 1 — 3

 Total ..................................... 67 37 47 40 24 215 

 1

This source caused fires usually involving welders' clothing or oxyfuel/grease. However, on four occasions undetected hot slag 

caused coal and belt fires. In another instance, undetected hot slag caused a coal chute smoldering fire, which, upon water 

application, produced a flashback accompanied by a gas explosion, resulting in one fatality. 

Figure 7.—Number of fires and fire injuries for surface coal mines by state, 1990–1999. 

17 
Figure 8.—Number of fires, fire injuries, risk rates, and coal production for surface coal mines by time period and employees' working 

hours, 1990–1999. 

18 

Figure 9.—Major variables for surface coal mine fires, 1990–1999. (FE = portable fire extinguisher) 
19 

Table 22.—Number of fires for surface coal mines by method of detection and time period, 1990–1999 

Method of detection 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Visual method:

 Flames/flash fires . . . . . . . . . . . . . . . . . . . . 
 22 9 17 14 7 69

 Smoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 4 8 — 5 4 21

 Smoldering . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — — 1

 Late smoke detection . . . . . . . . . . . . . . . . . 
 6 2 7 9 4 28

 Glow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — — 1 — — 1

 Sparks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 20 8 11 7 5 51

Electrical/mechanical sparks ........... 
 1 5 — — 1 7

 Radiator smoke/oil mist spray . . . . . . . . . . 
 1 — — 1 — 2 

Undetected ........................... 
 4 2 4 2 1 13 

Fire alarm/electrical trip warning . . . . . . . . . . . 
 1 — — 1 — 2 

Smelled smoke . . . . . . . . . . . . . . . . . . . . . . . . 
 — 1 2 — — 3 

Explosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 5 — 2 — 1 8 

Power loss . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 — 1 — — 1 2 

Popping sound ........................ 
 2 1 3 1 — 7

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 67 37 47 40 24 215 

Table 23.—Number of fires for surface coal mines by suppression method and time period, 1990–1999 

Suppression method 

Time period

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Manual/FE1 ........................... 16 7 10 7 4 44 

Portable fire extinguisher 8 8 1 10 4 31 

FE-water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 15 5 6 44 

FE-water/foam/dry chemical power . . . . . . . . 23 15 18 15 5 76 

Coal spread-water-compaction-removal2 .... — — — 2 — 2 

FSS-dry chemical powder-water . . . . . . . . . . 2 — — 1 2 5 

Destroyed/heavily damaged3 ............. 3 4 3 — 3 13

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 37 47 40 24 215 

FE Portable fire extinguisher

FSS Machine fire suppression system
 1

Methods used by welders to extinguish clothing or oxyfuel/grease fires. 2

Methods used to extinguish spontaneous combustion/hot coal fires. 3

Due to failure of other firefighting methods, late fire detection, or undetected fires.
 

Table 24.—Number of fires for surface coal mines by equipment involved and time period, 1990–1999 

Equipment 

Time period

90-91 92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Air compressor . . . . . . . . . . . . . . . . . . . . . 2 — — — —
 2 

Oxyfuel torch . . . . . . . . . . . . . . . . . . . . . . 20 12 14 7 6
 59 

Heater/maintenance equipment ........ 8 1 5 3 4
 21 

Beltline/drive/pulley . . . . . . . . . . . . . . . . . — — 2 1 — 
 3 

Crusher/dust collector . . . . . . . . . . . . . . . 1 — 2 2 — 
 5 

Facility ........................... 1 — 1 1 — 
 3 

Other/unknown . . . . . . . . . . . . . . . . . . . . . 4 2 5 6 4
 21 

Mobile equipment1 .................. 31 22 18 20 10 
 101

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 37 47 40 24 
 215 

 1

Includes haulage/utility trucks, loaders, dozers, drills, shovels, backhoes, buckets, excavators, scrapers,

auger/miners, and excavators. 

Table 25.—Number of fires for surface coal mines by location and time period, 1990–1999 

Location 90-91 

Time period 

92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Flame cutting/welding areas1 .............................. 21 12 13 7 5 58

Coal silos/loading dock/refuse pile/abandoned coal pit areas ..... 1 2 6 4 3 16

Beltline area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 — 2 2 — 5 

Dust collector/baghouse/crusher areas ...................... 2 — 2 2 — 6 

Facility ............................................... 1 — 1 1 1 4 

Maintenance areas ...................................... 11 3 5 6 4 29

Mobile equipment working areas2 ........................... 30 20 18 18 11 97

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 37 47 40 24 215 1

Includes coal chute, beltline, bucket/transfer house, shaft, dust collector and coal chute areas, and mobile equipment maintenance areas. 2

Includes mining, haulage, loading, and drilling areas. 
20 

Table 26.—Number of fires for surface coal mines by burning material and time period, 1990–1999 

Burning material 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Oxyfuel/hose/grease/clothing . . . . . . . . . . . . . . . . . . . 
 20 9 13 8 5 55

Coal/coal dust/straw/refuse . . . . . . . . . . . . . . . . . . . . 
 5 2 7 4 5 23

Crusher/dust collector/furnace/baghouse .......... 
 3 — 1 2 — 6 

Belt/idler/pulleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — 2 2 — 5 

Facility/content .............................. 
 1 — 1 1 — 3 

Flammable liquid/refuel fuel . . . . . . . . . . . . . . . . . . . . 
 9 4 4 7 5 29

Hydraulic fluid/fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 23 16 19 12 6 76 

Electrical system/batteries/collector ring/breaker . . . . 
 2 5 — 4 1 12 

Air compressor/transmission oil . . . . . . . . . . . . . . . . . 
 2 1 — — 1 4 

Natural gas/chemicals . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — 1 2

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 67 37 47 40 24 215 

Table 27.—Number of fire injuries per number of fires causing injuries and total fires at surface coal mines by year, ignition source, 

equipment involved, and location, 1990–1999 

Year 

No. fires 

causing 

injuries

No. 

total 

fires

No. 

fire 

injuries 

Ignition source Equipment Location 

1990 

19913 

1992 

1993 

1994 

1995 

1996 

1997 

1998 

1999 

. . . 

.. 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

11 

3 

1 

3 

1 

4 

6 

4 

5 

3 

1 

4 

1 

1 

2 

4 

2 

1 

2 

2 

4 

4 

3 

1 

3 

2 

1 

2 

4 

3 

1 

1 

1 

2 

1 

38 

29 

20 

17 

27 

20 

20 

20 

13 

11 

11 

3 

1 

3 

1 

4 

5 

4 

5 

3 

1 

4 

1 

1 

2 

4 

2 

1 

2 

2 

4 

4 

3 

1 

3 

2 

1 

2 

4 

3 

1 

1 

1 

2 

1 

Flame cutting/welding spark/slag/flame ........ 

Heat source-flammable liquid . . . . . . . . . . . . . . . . 

Mechanical friction ........................ 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Flammable liquid on hot surfaces . . . . . . . . . . . . . 

Heat source-flammable liquid . . . . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Flame cutting/welding spark/slag/flame ........ 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Flammable liquid on hot surfaces . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame ........ 

Heat source-flammable liquid . . . . . . . . . . . . . . . . 

Engine malfunction . . . . . . . . . . . . . . . . . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Flame cutting/welding spark/slag/flame ........ 

Heat source-flammable liquid . . . . . . . . . . . . . . . . 

Conveyor belt friction . . . . . . . . . . . . . . . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Heat source-flammable liquid ................ 

Flame cutting/welding spark/slag/flame . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Engine malfunction . . . . . . . . . . . . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame . . . . . . . . 

Heat source-refueling fuel . . . . . . . . . . . . . . . . . . 

Heat source-flammable liquid ................ 

Flammable liquid on hot surfaces . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame . . . . . . . . 

Flame cutting/welding spark/slag/flame ........ 

Flammable liquid on hot surfaces . . . . . . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces . . . 

Gas explosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Flammable liquid on hot surfaces ............. 

Flame cutting/welding spark/slag/flame . . . . . . . . 

Oxyfuel torch . . . . . . 

Heater/air compressor 

Mobile equipment2 . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Heater/furnace . . . . . 

Oxyfuel torch . . . . . . 

Mobile equipment2 . . 

Oxyfuel torch . . . . . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Oxyfuel torch . . . . . . 

Heater . . . . . . . . . . . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Oxyfuel torch . . . . . . 

Heater/maintenance

equipment. 

Beltline . . . . . . . . . . . 

Mobile equipment2 . . 

Heater . . . . . . . . . . . . 

Oxyfuel torch . . . . . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Oxyfuel torch . . . . . . 

Heater . . . . . . . . . . . . 

Heater . . . . . . . . . . . . 

Mobile equipment2 . . 

Oxyfuel torch . . . . . . 

Oxyfuel torch . . . . . . 

Heater . . . . . . . . . . . . 

Mobile equipment2 . . 

Mobile equipment2 . . 

Heater . . . . . . . . . . . . 

Oxyfuel torch . . . . . . 

1 Flame cutting/welding areas.

Refuse/maintenance areas. 

Drilling area. 

Haulage area. 

Maintenance area. 

Furnace room/maintenance

 area. 

Flame cutting/welding areas/

 coal chute areas.1 

Loading/haulage/ drilling/

 mining areas. 1 Flame cutting/welding areas.

Drilling/mining areas. 

Maintenance area. 1 Flame cutting/welding areas.

Maintenance area. 

Maintenance area. 

Haulage area. 1 Flame cutting/welding areas.

Maintenance area. 

Beltline area. 

Mining area. 

Refuse area. 1 Flame cutting/welding areas.

Drilling/haulage/mining areas. 

Loading/hopper areas. 

Haulage areas. 1 Flame cutting/welding areas.

Maintenance area. 

Maintenance area. 

Maintenance area. 1 Flame cutting/welding areas.1 Flame cutting/welding areas.

Maintenance area. 

Haulage area. 

Mining area. 

Maintenance area. 1 Flame cutting/welding areas.

Total . . . 94 215 94 1

Includes beltline area, bucket and transfer houses, coal chute and dust collector areas, and mobile equipment maintenance areas. 2

Includes trucks, dozers, loaders, drills, shovels, and buckets.
 3

During 1991, there was 1 fire fatality.
 
 

 

21 

Ignition Source 

The number of fires and fire injuries by ignition source and 

time period is shown in tables 21 and 27. The leading sources 

were hydraulic fluid/fuel sprayed onto equipment hot surfaces 

(76 fires or 35% with 22 injuries), followed by flame 

cutting/welding spark/slag/flames (59 fires or 27% with 

44 injuries), spontaneous combustion/hot coal (21 fires or 10%), 

and flammable liquid/refueling fuel on hot surfaces (18 fires 

or 8% with 7 injuries). Other ignition sources were 

engine/mechanical malfunctions/friction/explosions (11 fires), 

heat sources (10 fires), electrical short/arcing (8 fires), overheated oil (4 fires), conveyor belt friction (3 fires), and natural 

gas explosions (2 fires). Three ignition sources were unknown. 

The flame cutting/welding spark/slag/flame ignition source 

caused fires usually involving welders' clothing or oxyfuel/ 

grease (grease embedded in the equipment's mechanical components). However, in four instances undetected hot slag caused 

coal belt ignitions. In another instance, undetected hot slag 

caused a coal chute smoldering fire, which, upon application of 

water, produced a flashback accompanied by a gas explosion 

(causing one fatality). 

Forty-two of the mobile equipment hydraulic fluid/fuel fires 

became large fires, which at times required fire brigades and fire 

department interventions. On at least five occasions, the cab 

was suddenly engulfed in flames, forcing the operators to exit 

under hazardous conditions, probably due to the ignition of 

flammable vapors and mists that penetrated the cab. Of note is 

that most of the hydraulic fluid/fuel fires were caused when 

hydraulic fluids sprayed onto equipment hot surfaces; subsequently, these fires involved the fuel lines. 

During the first through fourth periods, the largest number 

of fires were caused by hydraulic fluid/fuel sprayed onto 

equipment hot surfaces. During the fifth period, the largest 

number of fires were caused by hydraulic fluid/fuel sprayed 

onto equipment hot surfaces and flame cutting/welding 

spark/slag/flame sources (see table 21). 

Method of Detection 

Table 22 shows the number of fires by method of detection 

and time period. The most frequent methods were operators 

who saw the fires when they started as flames/flash fires, 

welders who saw sparks, miners who saw smoke long after the 

fires had started, and miners who saw smoke shortly after the 

fires had started. Thirteen fires were undetected. Other 

methods of detection were miners who heard an explosion, 

operators who heard a popping sound, miners who saw 

electrical/mechanical sparks or smelled smoke, operators who 

saw radiator white smoke/oil mist spray or experienced power 

loss, and miners who heard an electrical trip warning or fire 

alarm. The largest number of fires were detected by flames/ 

flash fires throughout the periods (table 22). 

Suppression Method 

Table 23 shows the number of fires by suppression method 

and time period. The most common methods were portable fire 

extinguishers, foam, dry chemical powder, and water. These 

were followed by manual methods with or without portable fire 

extinguishers and water or portable fire extinguishers alone. Five 

pieces of mobile equipment involved in fires had machine fire 

suppression systems. Dual activation (three activations) of 

machine fire suppression and engine shutoff systems succeeded 

in temporarily abating the fires. However, the flames reignited, 

fueled by the flow of pressurized fluids entrapped in the lines 

(not affected by the engine shutoff operation), which hindered the 

operators' safe escape. Most of the mobile equipment hydraulic 

fluid/fuel fires became large fires, which required at least 15 fire 

brigade and fire department interventions because of the 

continuous flow of fluid/fuel from the pumps due to engine 

shutoff failure, lack of an emergency hydraulic line drainage 

system, difficulty in activating available emergency systems at 

ground level, or lack of effective and rapid local firefighting 

capabilities. (Fire-resistant hydraulic fluid is not required for 

equipment use at surface coal operations.) Other methods included coal spread, water, compaction, and removal. Fire 

brigades and fire departments, which were required in at least 26 

instances, fought the mobile equipment fires and other large fires 

with foam, dry chemical powder, and water. However, 13 fires 

destroyed or heavily damaged equipment (including six pieces of 

mobile equipment) because of failure of other firefighting 

methods, late fire detection, undetected fires, or fire size. 

During the first through fourth periods, the largest number 

of fires were suppressed with portable fire extinguishers, foam, 

dry chemical powder, and water. During the fifth period, the 

largest number of fires were suppressed with portable fire 

extinguishers and water (see table 23). 

Equipment Involved 

Table 24 shows the number of fires by equipment involved 

and time period. The equipment most often involved was 

mobile equipment (trucks, dozers, loaders, drills, shovels, backhoes, buckets, scrapers, excavators, and augers). This was 

followed by oxyfuel torches, heaters, and maintenance equipment. Other equipment included crushers and dust collectors; 

beltlines, drives, and pulleys; facilities; and air compressors. 

The largest number of fires involved mobile equipment 

throughout the periods (table 24). 

Location 

Table 25 shows the number of fires by location and time 

period. The most common locations were mobile equipment 

working areas (mining, haulage, loading, and drilling areas). 

These were followed by flame cutting/welding areas (at beltline 
22 

areas, shaft, coal chute and dust collector areas, bucket and 

transfer houses, and mobile equipment maintenance areas) and 

maintenance areas. Other fire locations included coal silos, 

loading docks, refuse piles, abandoned and coal pit areas, dust 

collectors, baghouses, crushers and beltline areas, and facilities. 

The largest number of fires throughout the periods occurred at 

mobile equipment working areas (table 25). 

Burning Materials 

Table 26 shows the number of fires by burning material and 

time period. The material most often involved was hydraulic 

fluid/fuel, followed by oxyfuel/grease/clothing, flammable 

liquids, coal and coal dust, and straw and refuse. Other burning 

materials included electrical systems, batteries, collector rings 

and breakers, dust collectors, baghouses, and furnaces. Belts, 

idlers and pulleys, air compressors, transmission oil, facilities 

and contents, and natural gas and chemicals also burned during 

fires. The largest number of fires involved hydraulic fluid/fuel 

throughout the periods (table 26). 

Fire Injuries 

Table 27 shows the number of fire injuries per number of 

fires causing injuries and total fires by year, ignition source, 

equipment involved, and location during 1990–1999. Overall, 

there were 93 injuries and 1 fatality caused by 94 fires. 

The greatest number of fire injuries occurred in 1990 

(19 injuries caused by 19 fires) and 1991 (13 injuries and 

1 fatality caused by 14 fires). The ignition sources that caused 

most of the fire injuries were flame cutting/welding spark/ 

slag/flames and hydraulic fluid/fuel sprayed onto equipment hot 

surfaces. These were followed by flammable liquid on hot 

surfaces and by heat sources and pressurized can explosions. 

Other ignition sources were engine/mechanical malfunctions/ 

friction and conveyor belt friction. The equipment most often 

involved included oxyfuel torches, mobile equipment, heaters, 

maintenance equipment, dust collectors and samplers, and 

beltlines. The locations where most of the fire injuries occurred 

were flame cutting/welding and mobile equipment working 

areas. Other fire locations were maintenance, dust collector, 

and beltline areas. 

The fire fatality in Montana in 1991 was caused by a flashback accompanied by a gas explosion that engulfed the mechanic who was hosing down a coal chute smoldering fire. The 

smoldering of coal was due to undetected hot slag produced 

during flame cutting/welding operations [MSHA 1991b]. 

COAL PREPARATION PLANT FIRES 

Table 28 and figure 10 show the number of fires and fire 

injuries for coal preparation plants by state during 1990–1999. 

Table 28 also shows the risk rates, employees' working hours, and 

lost workdays by state. For coal preparation plants, 91 fires 

occurred in 11 states during 1990–1999. Twenty-three of those 

fires caused 25 injuries (the yearly average was 9.1 fires and 

2.5 injuries). Ten fires and eight injuries involved contractors. 

The Ewhr value was 241 × 106

 hr (Irr = 0.021), and the LWD 

value was 198. 

Pennsylvania had the most fires (24 fires and 4 injuries), 

whereas West Virginia (22 fires and 7 injuries) and Kentucky 

(22 fires and 7 injuries) had the most fire injuries. Among these 

states, Kentucky had the highest injury risk rate value (Irr = 

0.025). 

Table 29, partly illustrated in figure 11, shows the number of 

fires, fire injuries, risk rates, employees' working hours, and lost 

workdays by time period. The number of fires decreased during 

most of the periods (an increase is seen only during the last 

period). The number of fire injuries show a decrease followed 

by an increase during the periods, accompanied by a decline in 

employees' working hours throughout the periods. The Irr 

values follow patterns similar to those shown by the injury 

values (see table 29 and figure 11). 

Tables 30–35 show the number of fires by ignition source, 

method of detection and suppression, equipment involved, 

location, and burning material by time period. Figure 12 shows 

the major variables during 1990–1999. Table 36 shows the fire 

injuries per number of fires causing injuries and total fires by 

year, ignition source, equipment involved, and location. 

Ignition Source 

The number of fires and fire injuries by ignition source and 

time period is show in tables 30 and 36. The leading source was 

spontaneous combustion/hot coal (24 fires or 26%). This was 

followed by flame cutting/welding spark/slag/flames (15 fires or 

17% with 8 injuries), hydraulic fluid/fuel sprayed onto equipment hot surfaces (10 fires or 11% with 6 injuries), and conveyor belt friction (9 fires or 10% with 1 injury). The flame 

cutting/welding spark/slag/flame ignition source caused fires 

usually involving welders' clothing or oxyfuel/grease (grease 

embedded in the equipment's mechanical components). However, in one instance undetected hot slag caused a storage 

facility fire. Other ignition sources were electrical short/arcing 

(nine fires), flammable liquid/refueling fuel on hot surfaces (six 

fires), engine/mechanical malfunctions/friction (three fires), 

overheated oil (two fires), and a chemical explosion (one fire). 

Eight ignition sources were unknown. The spontaneous 

combustion/hot coal fires were detected long after the fires had 

started due to lack of continuous and early combustion gas/smoke 

detection systems. Two of the mobile equipment hydraulic fluid/ 

fuel fires became large fires, which at times required fire brigade 

and fire department interventions. In two instances the cab was 

suddenly engulfed in flames, forcing the operators to exit under 

hazardous conditions, probably due to the ignition of flammable 

vapors and mists that penetrated the cab. Of note is that most of 

the hydraulic fluid/fuel fires were caused when hydraulic fluids 

sprayed onto equipment hot surfaces; subsequently, these fires 

involved the fuel lines. 

During the first, third, fourth, and fifth periods, the largest 

number of fires were caused by spontaneous combustion/hot 

coal. During the second period, the largest number of fires were 

caused by spontaneous combustion/hot coal and by flame 

cutting/welding spark/slag/flames (see table 30). 
23 

Figure 10.—Number of fires and fire injuries for coal preparation plants by state, 1990–1999. 

Figure 11.—Number of fires, fire injuries, and risk rates for coal preparation plants by time period and employees' working hours, 1990–1999. 
24 

Table 28.—Number of fires, fire injuries, and risk rates for coal preparation plants by state, 

employees' working hours, and lost workdays, 1990–1999 

State1 No. fires1 1 No. injuries LWD2 Ewhr,2

 106 hr 
 Irr3

Alabama ............ 

Illinois . . . . . . . . . . . . . . 

Indiana . . . . . . . . . . . . . 

Kentucky . . . . . . . . . . . . 

Maryland . . . . . . . . . . . . 

Ohio . . . . . . . . . . . . . . . 

Pennsylvania ........ 

Utah . . . . . . . . . . . . . . . 

Virginia . . . . . . . . . . . . . 

West Virginia . . . . . . . . 

Wyoming . . . . . . . . . . . . 

Other states . . . . . . . . . 

 Total . . . . . . . . . . . . . 

4 

3 

1 

22 

1 

2 

24 

1 

6 

22 

5 

— 

91 

— 

2 

— 

7 

— 

1 

4 

1 

2 

7 

1 

— 

25 

— 

14 

— 

83 

— 

7 

60 

— 

— 

34 

— 

— 

198 

11 

15 

8.4 

56 

1 

12.5 

34.4 

2.1 

21.5 

59.5 

4.1 

15.3 

241 

— 
 

0.027

— 
 

0.025

— 
 

0.016

0.023

0.095

0.019

0.024

0.049

—3

0.021
 


 


 


 


 


 


 


 


 

1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to MSHA formula reported in the "Methodologies" section.
 

Table 29.—Number of fires, fire injuries, and risk rates for coal preparation plants by time period, 

employees' wor

90-91 

Number of fires1 . . . . . . . . . 23 

king hours, a

92-93 

22 

nd lost workdays, 1990–1999 

Time period 

94-95 96-97 

18 8 

98-99 

20 

90-99 

91 

Number of fire injuries1 .... 7 6 8 1 3 25

LWD2 ................. 116 19 37 — 26 198 

Ewhr,2

 106 hr . . . . . . . . . . . . 60 50 48 44 39 241 

Irr3 .................... 0.023 0.024 0.033 0.005 0.016 3

0.021 1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to MSHA formula reported in the "Methodologies" section.
 

Table 30.—Number of fires for coal preparation plants by ignition source and time period, 1990–1999 

Ignition source 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Heat source . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 — 2 — 1 4 

Conveyor belt friction . . . . . . . . . . . . . . . . . . . . . 1 2 2 — 4 9 

Flame cutting/welding spark/slag/flame1 ...... 4 6 2 1 2 15

Chemical explosion . . . . . . . . . . . . . . . . . . . . . . — — — 1 — 1 

Spontaneous combustion/hot coal ........... 5 6 4 4 5 24

Flammable liquid/refueling fuel on hot surfaces/

 explosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1 1 — 1 6 

Electrical short/arcing2 .................... 2 4 1 — 2 9 

Overheated oil .......................... — 1 — — 1 2 

Engine/mechanical malfunctions/friction ...... 1 — 1 1 — 3 

Hydraulic fluid/fuel on equipment hot surfaces . . 3 2 2 1 2 10

Unknown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 — 3 — 2 8

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 22 18 8 20 91 

 1

This source caused fires usually involving welders' clothing or oxyfuel/grease. However, in at least one instance undetected hot slag 

caused a storage facility fire.

 2

On one occasion this source caused a coal dust explosion in a dust collector. 
25 

Table 31.—Number of fires for coal preparation plants by method of detection 

and time period, 1990–1999 

Method of detection 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Visual:

 Flames/flash fires . . . . . . . 8 3 3 2 4 20

 Smoke . . . . . . . . . . . . . . . 2 4 4 1 3 14

 Sparks . . . . . . . . . . . . . . . 1 5 1 1 1 9

 Smoldering . . . . . . . . . . . . — — — — 1 1

 Late smoke detection . . . . 6 9 6 3 8 32

 Dim lights . . . . . . . . . . . . . — — — — 1 1 

Explosion . . . . . . . . . . . . . . . 
 1 — — 1 — 2 

Popping sound ........... 
 1 — — — — 1 

Undetected .............. 
 2 1 3 — 1 7 

Touched hot spots ........ 
 1 — 1 — — 2 

Other . . . . . . . . . . . . . . . . . . . 
 — — — — 1 1

 Total . . . . . . . . . . . . . . . . 
 23 22 18 8 20 91 

Table 32.—Number of fires for coal preparation plants by suppression method and time period, 1990–1999 

Suppression method 

Time period 

90-91 92-93 94-95 96-97 98-99 90-99 

No. fires No. fires No. fires No. fires No. fires No. fires 

Manual/FE1 ........................... 3 5 4 1 1
 14

FE-foam/water/dry chemical powder . . . . . . . 8 7 2 1 8
 26

Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 4 1 5
 20

Coal spread-water-compaction removal2 .... 2 5 4 3 4
 18

Destroyed/heavily damaged3 ............. 3 2 4 2 2
 13

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 22 18 8 20 
 91

 FE Portable fire extinguisher.

 1

Methods used by welders to extinguish clothing or oxyfuel/grease fires. 

 2

Methods used to extinguish spontaneous combustion/hot coal fires. In one case, a CO2 permanent fire extinguishment system was used.

 3

Due to failure of other firefighting methods, late fire detection, or undetected fires. 

Table 33.—Number of fires for coal preparation plants by equipment involved and time period, 1990–1999 

Equipment 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Electrical control/power system . . . . . . . . 
 2 3 1 — 1 7 

Oxyfuel torch . . . . . . . . . . . . . . . . . . . . . . 
 4 6 2 1 2 15

Heater/maintenance equipment ........ 
 2 — 3 — — 5 

Airlock gate . . . . . . . . . . . . . . . . . . . . . . . . 
 1 — — — — 1 

Dust sampler/collector/dryer/washer . . . . 
 4 — — 1 1 6 

Beltline/drive/pulley . . . . . . . . . . . . . . . . . 
 1 3 2 — 5 11 

Facility ........................... 
 1 — 3 — 1 5 

Chemical tank . . . . . . . . . . . . . . . . . . . . . . 
 — — — 1 — 1 

Hopper ........................... 
 — — — — 2 2 

Mobile equipment1 .................. 
 5 4 3 2 3 17

Air compressor . . . . . . . . . . . . . . . . . . . . . 
 — 1 — — — 1 

Other2 ............................ 
 3 5 4 3 5 20

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 23 22 18 8 20 91 1

Includes loader, dozer, and haulage/utility trucks.

2

Includes nonequipment (mostly coal piles). 
Table 34.—Number of fires for coal preparation plants by location and time period, 1990–1999 

Location 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Flame cutting/welding areas1 .................... 4 6 2 1 2 15

Beltline/rail dump areas . . . . . . . . . . . . . . . . . . . . . . . . 3 2 3 — 4 12 

Coal silos/stock pile/coal feeder .................. 4 5 5 4 5 23

Power station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — 1 — — 1 2 

Maintenance areas ............................ 3 1 2 — 1 7 

Thermal dryer/dust collector/washer/hopper areas . . . 3 2 — — 2 7 

Airlock gates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 — — — 2 

Charging station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — — 1 — 1 

Mobile equipment working areas2 ................. 3 3 3 2 3 14

Facility area ................................. 2 1 3 — 2 8

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 22 18 8 20 91 

 1

Includes packing material building, plastic material storage, coal bypasses, loadout facilities, raw coal silos, drawoff tunnels, 

coal feeders, shops, coal hoppers, and mobile equipment maintenance areas.

 2

Includes loading and haulage areas. 

26 

Table 35.—Number of fires for coal preparation plants by burning material and time period, 1990–1999 

Burning material 

Time period 

90-91 

No. fires 

92-93 

No. fires 

94-95 96-97 

No. fires No. fires 

98-99 

No. fires 

90-99 

No. fires 

Oxyfuel/grease/clothing . . . . . . . . . . . . . . . . . . . . . 2 4 1 1 1 9 

Alcohol/chemicals .......................... 1 — — 1 — 2 

Flammable liquids/oil/grease . . . . . . . . . . . . . . . . . 2 2 3 — 1 8 

Belt/drive/pulley . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 3 — 4 13 

Facility/content ............................ 1 — 3 — 1 5 

Coal/coal dust/wood/insulation/rubber tires/

 packing materials . . . . . . . . . . . . . . . . . . . . . . . . 8 7 7 4 7 33

Electrical systems/wires/cables . . . . . . . . . . . . . . . 1 4 — — 2 7 

Hydraulic fluid/fuel . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 1 1 3 10

Equipment mechanical components ........... 2 — — 1 1 4

 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 22 18 8 20 91 

Table 36.—Number of fire injuries per number of fires causing injuries and total fires at coal preparation plants by year, ignition source, 

equipment involved, and location, 1990–1999 

Year 

No. fires 

causing 

injuries 

No. 

total 

fires 

No. 

fire 

injuries 

Ignition source Equipment Location 

1990 

1991 

1992 

1993 

1994 

1995 

1996 

1997 

1998 

1999 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

. . . 

2 

1 

1 

1 

1 

3 

1 

1 

1 

1 

1 

1 

1 

2 

1 

1 

— 

1 

1 

1 

11 

— 

12 

— 

11 

— 

11 

— 

10 

— 

— 

8 

— 

— 

5 

3 

10 

10 

3 

1 

1 

1 

1 

3 

1 

1 

1 

1 

1 

1 

1 

3 

1 

1 

— 

1 

1 

1 

Refueling fuel on hot surfaces ................ 

Flame cutting/welding spark/slag/flame . . . . . . . . . 

Electrical short/arcing-coal dust explosion ....... 

Heat source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hydraulic fluid/fuel on equipment hot surfaces .... 

Flame cutting/welding spark/slag/flame ......... 

Electrical short-flammable liquid . . . . . . . . . . . . . . . 

Flame cutting/welding spark/slag/flame ......... 

Hydraulic fluid/fuel on equipment hot surfaces .... 

Heat source-flammable liquid ................. 

Refueling fuel on hot surfaces . . . . . . . . . . . . . . . . 

Conveyor belt friction . . . . . . . . . . . . . . . . . . . . . . . 

Flame cutting welding spark/slag/flame ......... 

Hydraulic fluid/fuel on equipment hot surfaces .... 

Mechanical malfunction ..................... 

Flame cutting/welding spark/slag/flame ......... 

— 

Flame cutting/welding spark/slag/flame ......... 

Hydraulic fluid/fuel on equipment hot surfaces .... 

Heat source-flammable liquid . . . . . . . . . . . . . . . . . 

Pump/heater . . . . . . . . . . Pump housing/maintenance

 areas. 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

Dust sampler . . . . . . . . . Dust collector area. 

Heater . . . . . . . . . . . . . . . Maintenance area. 

Mobile equipment2 ..... Loading area. 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

Thermal dryer . . . . . . . . . Dryer area. 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

Mobile equipment2 ..... Loading area. 

Heater . . . . . . . . . . . . . . . Maintenance area. 

Maintenance equipment . Maintenance area. 

Beltline . . . . . . . . . . . . . . Beltline area. 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

Mobile equipment2 ..... Loading/haulage areas. 

Mobile equipment2 . . . . . Haulage area. 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

— — 1 Oxyfuel torch . . . . . . . . . Flame cutting/welding areas.

Mobile equipment2 ..... Loading area. 

Thermal dryer . . . . . . . . . Dryer area. 

Total . . . 23 91 25 1

Includes loadout facilities, sump and coal feeder areas, shops, packing material building, and plastic material storage. 2

Includes loaders and trucks. 
27 

Figure 12.—Major variables for coal preparation plant fires, 1990–1999. (FE = portable fire extinguisher) 

Method of Detection 

Table 31 shows the number of fires by method of detection and 

time period. The most frequent method was miners who saw 

smoke long after the fires had started, followed by operators who 

saw the fires when they started as flames/flash fires, miners who 

saw smoke shortly after the fire had started, and welders who saw 

sparks. Other methods of detection were miners who touched hot 

spots, miners who saw smoldering of coal or heard an explosion, 

and operators who heard a popping sound or saw dimming of 

equipment lights. In one instance, a coal sampler detected a coal 

silo smoldering fire. Seven fires were undetected. 

During the first period, the largest number of fires were 

detected when they started as flames/flash fires. During subsequent periods, the largest number of fires were detected late by 

smoke (see table 31). 

Suppression Method 

Table 32 shows the number of fires by suppression method and 

time period. The most common methods were water alone and 

coal spread, water, compaction, and removal. These were followed by portable fire extinguishers, foam, dry chemical powder 

and water, manual techniques with or without portable fire 

extinguishers, and dry chemical and water alone. In one instance, 

a permanent CO2 fire-extinguishing system was used to put out a 

coal silo smoldering fire. None of the mobile equipment involved 

in fires had machine fire suppression systems. Most of the hydraulic fluid/fuel fires became large fires, which in one instance 

required a fire brigade and fire department intervention because 

of the continuous flow of fluid/fuel from the pumps due to engine 

shutoff failure, lack of an emergency hydraulic line drainage system (the flow of pressurized fluids entrapped in the lines was not 

affected by the engine shutoff operation), difficulty in activating 

available emergency systems at ground level, or lack of effective 

and rapid local firefighting response capabilities. (Fire-resistant 

hydraulic fluid is not required for equipment use at surface coal 

operations.) 

Fire brigades and fire departments (required on at least nine 

occasions) fought the mobile equipment fires and other large fires 

with foam, dry chemical powder, and water. However, 13 fires 

destroyed or heavily damaged equipment (including four pieces 

of mobile equipment) because of failure of other firefighting 

methods, late fire detection, undetected fires, or fire size. 

During the first, second, and fifth periods, the largest number 

of fires were suppressed with portable fire extinguishers, foam, 

dry chemical powder, and water. During the third period, the 

largest number of fires were extinguished by coal spread, water, 
28 

compaction, and removal; manually with or without portable fire 

extinguishers; and water alone. During the fourth period, the 

largest number of fires were extinguished by coal spread, water, 

compaction, and removal (see table 32). 

Equipment Involved 

Table 33 shows the number of fires by equipment involved 

and time period. The equipment most often involved included 

mobile equipment (loaders, dozers, and trucks); oxyfuel torches; 

and beltlines, drives, and pulleys. Other equipment included 

electrical control and power systems, dust collectors and samplers, dryers and washers, heaters and maintenance equipment, 

hoppers, airlock gates, chemical tanks, and air compressors. 

During the first period, the largest number of fires involved 

mobile equipment. During the second period, the largest number of fires involved oxyfuel torches. During the third period, 

the largest number of fires involved heaters, maintenance equipment, facilities, and mobile equipment. During the fourth and 

fifth periods, the largest number of fires involved mobile equipment (see table 33). 

Location 

Table 34 shows the number of fires by location and time 

period. The most common locations were coal silos, stockpile, 

and coal feeder areas and flame cutting/welding areas (at packing material buildings, plastic material storage, coal bypasses, 

loadout facilities, raw coal silos, drawoff tunnels, coal feeders, 

shops, coal hoppers, and mobile equipment maintenance areas). 

Other fire locations were mobile equipment working areas 

(loading and haulage areas), beltline and rail dump areas, facilities, and maintenance areas. Also affected by fires were thermal dryer, dust collector, washer, and hopper areas; power 

stations; airlock gates; and charging stations. 

During the first and second periods, the largest number of 

fires occurred at flame cutting/welding areas. During the third, 

fourth, and fifth periods, the largest number of fires occurred at 

coal silo, feeder, and stockpile areas (see table 34). 

Burning Materials 

Table 35 shows the number of fires by burning material and 

time period. The materials most often involved were coal and 

coal dust, insulation material, rubber tires, wood, and packing 

materials, followed by belts, drives, and pulleys and hydraulic 

fluid/fuel. Other burning materials were flammable liquids, 

oil/grease, oxyfuel/grease/clothing, electrical systems, wires and 

cables, facilities and contents, equipment mechanical components, and alcohol and chemicals. Throughout the periods the 

largest number of fires involved coal, coal dust, wood, 

insulation, rubber tires, and packing materials (table 35). 

Fire Injuries 

Table 36 shows the number of fire injuries, number of fires 

causing injuries, and total fires by year, ignition source, equipment involved, and location during 1990–1999. Overall, there 

were 25 injuries caused by 23 fires. 

The greatest number of fire injuries occurred in 1995 (five 

injuries caused by four fires) and 1992 (four injuries caused by 

four fires). The ignition sources that caused most of the fire injuries were flame cutting/welding spark/slag/flames, hydraulic 

fluid/fuel sprayed onto equipment hot surfaces, and flammable 

liquid/refueling fuel on hot surfaces. Other ignition sources 

were heat sources, mechanical malfunctions, electrical short/ 

arcing and coal dust explosion, and conveyor belt friction. The 

equipment most often involved included oxyfuel torches, mobile 

equipment, heaters, maintenance equipment, dust collectors and 

samplers, pumps, and beltlines. The fire locations where most 

of the fire injuries occurred were flame cutting/welding areas 

and mobile equipment working areas. Other fire locations were 

maintenance areas, dust collector areas, thermal dryer and 

beltline areas, and pump housings. 

SUMMARY OF MAJOR FIRE AND FIRE INJURY FINDINGS

 FOR ALL COAL MINING CATEGORIES
 

The major fire and fire injury findings for all coal mining 

categories for 1990–1999 are reported in tables 37–38. Table 39 

and figure 13 show the number of fires, fire injuries, risk rates, 

employees' working hours, and coal production (underground 

and surface coal mines only) by time period for all coal mining 

categories. Table 40 shows major findings (for underground 

coal mines only) for 1978–1992. 

For all coal mining categories, 458 fires occurred during 

1990–1999; 157 of those fires caused 164 injuries and 2 fatalities (Ewhr = 2,070 × 106

 hr, Irr = 0.016; CP (for underground 

and surface coal mines only) = 10,363 × 106

 st, Frr = 0.044, LWD 

= 14,753). Twenty-nine fires and 17 injuries involved contractors. 

Sixty-six fires required firefighting interventions by mine 

rescue teams (25 times in underground mines) and fire brigades 

and fire departments (at least 41 times at surface coal 

operations). In all, 51 fires destroyed or heavily damaged 

equipment (including 16 pieces of mobile equipment) because 

of failure of other firefighting methods, late fire detection, 

undetected fires, or fire size. A total of 114 fires were detected 

late, and 42 fires were undetected. The greatest number of fires 

and fire injuries occurred at surface coal mines; the highest risk 

rate values were also calculated for this category. 

For all coal operations, the ignition sources that caused 

the greatest number of fires were flame cutting/welding 

spark/slag/flames (103 fires or 23% with 69 injuries), hydraulic 

fluid/fuel sprayed onto equipment hot surfaces (98 fires or 21% 

with 29 injuries), spontaneous combustion/hot coal (62 fires or 

14%), electrical short/arcing (49 fires or 11% with 18 injuries), 

and conveyor belt friction (31 fires or 7% with 6 injuries). 
Table 37.—Major fire findings for all coal mining categories, 1990–1999 

Variables Underground coal mines Surface of underground coal mines Surface coal mines Coal preparation plants 

GT: No. fires: 

CP, 106 st: 

Frr: 

No. fires causing injuries: 

458 

10,363 

0.044 

157 

No. fires: CP, 106 st: 

Frr: No. fires causing injuries: 

87 

4,008 

0.022 

27 

No. fires: No. fires causing injuries: 

65 13 

No. fires: 

CP, 106 st: 

Frr: 

No. fires causing injuries: 

215 

6,355 

0.034 

94 

No. fires: No. fires causing injuries: 

91 23 

Ignition source ................... Electrical short/arcing/explosion 

Flame cutting/welding/spark/slag/flame 

Conveyor belt friction 

Spontaneous combustion 

Hydraulic fluid/fuel on equipment

hot surfaces Flame cutting/welding spark/slag/

flame Spontaneous combustion/hot coal Heat source 

Hydraulic fluid/fuel on equipment hot

surfaces Flame cutting/welding spark/slag/flame 

Spontaneous combustion/hot coal Flammable liquid-refueling fuel on hot

Spontaneous combustion/hot coal 

Flame cutting/welding spark/slag/

flame Hydraulic fluid/fuel on equipment

 hot surfaces Conveyor belt friction 

Method of detection ............... Late smoke detection 

Visual-sparks 

Visual-smoke 

CO/H2 gas sample 

Late smoke detection 

Visual-flames/flash fires 

Visual-smoke 

Visual-sparks 

surfaces Visual-flames/flash fires 

Visual-sparks 

Late smoke detection 

Visual-smoke 

Late smoke detection 

Visual-flames/flash fires 

Visual-smoke 

Visual-sparks 

Suppression method .............. FE/water 

FE-DCP-rock dust/water 

Portable fire extinguisher 

Sealing/flooding/CO2/N2 gas injections 

FE-foam/water/DCP 

Manual/FE 

Coal spread-water-compactionremoval Portable fire extinguisher

FE-foam/DCP/water 

Manual/FE 

FE/water 

Portable fire extinguisher 

FE-foam/DCP/water 

Water 

Coal spread-water-compactionremoval Manual/FE 

Equipment involved ............... Mobile equipment1 

Oxyfuel torch 

Beltline/drive/pulley/feeder 

Electrical system/units/other 

Facility Mobile equipment1 

Oxyfuel torch 

Beltline/drive/pulley 

Mobile equipment1 

Oxyfuel torch 

Heater/maintenance equipment 

Dust collector/crusher 

Mobile equipment1 

Oxyfuel torch 

Beltline/drive/pulley 

Electrical control/power system 

Location . . . . . . . . . . . . . . . . . . . . . . . . Belt entries/feeder/slope/portal branch

areas Flame cutting/welding areas2 

Gobline/sealed/abandoned coal pit

areas Mining face/crosscut/intersection areas

Facility areas 

Mobile equipment working areas 

Flame cutting/welding areas2 

Beltline/drawoff tunnel areas 

Mobile equipment working areas 

Flame cutting/welding areas2 

Maintenance area 

Coal silo/pit areas/other 

Coal silos/feeder/stockpile

Flame cutting/welding areas2 

Mobile equipment working areas 

Beltline/rail dump areas 

Burning material .................. Electrical wires/cables/units/other 

Coal/coal dust 

Belt/drive/pulley/feeder 

Oxyfuel/grease/clothing 

Facility/content/other 

Hydraulic fluid/fuel 

Coal/methane 

Belt/drive/pulley 

Hydraulic fluid/fuel 

Oxyfuel/grease 

Flammable liquid/refueling fuel 

Coal/coal dust 

Coal/wood/insulation material/other 

Belt/drive/pulley 

Hydraulic fluid/fuel 

Oxyfuel/grease/clothing

Dry chemical powder. DCP Portable fire extinguisher. FE 1Includes scoops, bolters, shuttle cars, ore carts, 3-wheelers, trolleys, locomotives, rail runners, shearers, continuous miners, loaders, dozers, shovels, scrapers, drills, highlifts, excavators, 

backhoes, buckets, trucks, auger/miners, hoists, and power scalers.

2Includes longwall face and headgate; belt entries; beltline areas; drive, pulley, and feeder areas; overcasts; shops; storage silos; plastic/packing material buildings; shafts; coal chutes; dust 

collectors; elevator shafts; bucket/transfer housing; coal bypasses; drawoff tunnels; raw coal hoppers; and mobile equipment maintenance areas.

 NOTE.—Variables are listed in descending order of occurrence. 

29 
Table 38.—Major fire injury findings for all coal mining categories, 1990–1999 

Variables Underground coal mines Surface of underground coal mines Surface coal mines Coal preparation plants 

Grand total: No. fire injuries: 

No. fire fatalities: 

Ewhr, 106 hr: 

Irr: 

LWD: 

164 

2 

2,070 

0.016 

14,753 

No. fire injuries: 

Ewhr, 106 hr: 

Irr: LWD: 

34 

1,003 

0.0068 

208 

No. fire injuries: No. fire fatalities: 

Ewhr, 106 hr: 

Irr: LWD: 

12 

1 

97 

0.025 6,206 

No. fire injuries: No. fire fatalities: 

Ewhr, 106 hr: 

Irr: LWD: 

93 

1 

729 

0.026 8,141 

No. fire injuries: 

Ewhr, 106 hr: 

Irr: LWD: 

25 

241 

0.021 

198 

Ignition source . . . . . . . . . . . . . ........ Electrical short/arcing 

Flame cutting/welding spark/slag/flame Conveyor belt friction Heat source 

Flame cutting/welding spark/slag/flame Heat source Battery explosion Hydraulic fluid/fuel on equipment hot surfaces 

Flame cutting/welding spark/slag/ flame Hydraulic fluid/fuel on equipment hot surfaces Flammable liquid on hot surfaces Heat source 

Flame cutting/welding spark/slag/ flame Hydraulic fluid/fuel on equipment hot surfaces Refueling fuel on hot surfaces Electrical short/arcing-coal dust explosion 

Method of detection ................. Visual-smoke 

Visual-sparks Late smoke detection 

Visual-sparks Visual-flames Explosion Visual-flames/flash fire 

Visual-sparks Visual-flames/flash fires Visual-smoke/explosion 

Visual-sparks Visual-flames/flash fires Explosion 

Suppression method ................ FE-rock dust/DCP/water 

Manual/FE Portable fire extinguisher 

FE/manual Portable fire extinguisher FE-foam/DCP/water 

FE-manual FE-foam/DCP/water Portable fire extinguisher 

FE-manual FE-foam/water/DCP Portable fire extinguisher 

Equipment involved ................. Electrical power cables/systems/starter/

 voltage box/mobile equipment Oxyfuel torch Beltline/drive/pulley Heater 

Oxyfuel torch Heater Mobile equipment1 

Oxyfuel torch Mobile equipment1 Heater 

Oxyfuel torch Mobile equipment1 

Heater/maintenance equipment Dust collector/sampler 

Location . . . . . . . . . ................. Pump/power/charging stations/

 mobile equipment working areas Flame cutting/welding areas2 

Trolley track rails/transportation areas Belt entries 

Flame cutting/welding areas2 

Maintenance area Mobile equipment working areas Charging station 

Flame cutting/welding areas2 

Mobile equipment working areas Maintenance areas 

Flame cutting/welding areas2 

Mobile equipment working areas Maintenance area Dust collector area 

Burning material . . . ................. Electrical units/wires/cables 

Oxyfuel/grease/clothing Belt material Mobile equipment mechanical components 

Oxyfuel/grease/clothing Hydraulic fluid/fuel Batteries 

Oxyfuel/grease/clothing Hydraulic fluid/fuel Flammable liquids Pressurized can 

Oxyfuel/grease/clothingHydraulic fluid/fuel Flammable liquids/refueling fuels Dust collector liners

Dry chemical powder.

DCP Portable fire extinguisher. FE 1Includes scoops, shuttle cars, bolters, rail runners, jeeps, trucks, loaders, dozers, scrapers, shovels, highlifts, excavators, buckets, backhoes, drills, and tractors.

2Includes conveyor belt entries, beltline areas, longwall mining face, shops, loadout facilities, bucket/transfer houses, coal chutes, dust collectors, storage silos, sump areas, and mobile equipment 

working and maintenance areas. NOTE.—Variables are listed in descending order of occurrence. 

30 
31 

Figure 13.—Number of fires, fire injuries, risk rates, and coal production (underground and surface coal mines only) for all coal mining 

categories by time period and employees' working hours, 1990–1999. 

Table 39.—Number of fires, fire injuries, fire fatalities, and risk rates for all coal mining categories

by time period, employees' working hours, lost workdays, and coal production, 1990–1999 

90-91 

Time period 

92-93 94-95 96-97 98-99 90-99 

Number of fires1 .......... 132 91 104 61 70 458 

Number of fire injuries1 ..... 59 29 39 19 18 164 

Number of fire fatalities1 .... 2 — — — — 2 

LWD2 .................. 12,847 734 421 345 406 14,753 

Ewhr,2

 106 hr . . . . . . . . . . . . . 521 434 405 370 340 2,070 

CP,2

 106 st . . . . . . . . . . . . . . 2,004 1,928 2,059 2,155 2,218 10,363 

Frr3 .................... 0.066 0.047 0.051 0.028 0.032 3

0.944 

Irr3 ..................... 0.023 0.013 0.019 0.01 0.011 3

0.016 1

Derived from MSHA "Fire Accident Abstract" and "Fire Accident Report" publications.

2

Derived from MSHA "Injury Experience in Coal Mining" publications. 3

Calculated according to USBM and MSHA formulas reported in the "Methodologies" section. 

Table 40.—Major findings for underground coal mine fires, 1978–1992 

Category All fires Injury fires Fatal fires 

Ignition source . . . . . . . . . . . . . . . . . 

Detection . . . . . . . . . . . . . . . . . . . . . 

Burning substance . . . . . . . . . . . . . . 

Equipment involved . . . . . . . . . . . . . 

Location . . . . . . . . . . . . . . . . . . . . . . 

Successful extinguishing agent .... 

Electrical, friction, welding or

 cutting. 

Miner saw or smelled smoke,

 miner saw fire start, examiner

 saw or smelled smoke. 

Coal, electrical insulation, con-

 veyor belt or rollers. 

Conveyor belt, welding or cut-

 ting, trolley line, electrical

 equipment. 

Belt entry, working face, intake

 air course, track entry. 

Water, dry chemicals, rock

 dust. 

Electrical, friction, welding

 or cutting. 

Miner saw fire start, miner

 saw or smelled smoke. 

Coal, electrical insulation,

 conveyor belt or rollers. 

Trolley line, conveyor belt,

 welding or cutting, air

 compressor. 

Track entry, working face,

 belt entry, longwall. 

Water, dry chemicals, rock

 dust. 

Friction, welding or

 cutting. 

Miner saw fire start, miner

 saw or smelled smoke. 

Coal, conveyor belt or

 rollers, electrical

 insulation. 

Conveyor belt, air com-

 pressor, welding or cutting, continuous miner. 

Shaft bottom, intake air

 course, belt entry, working face. 

Water, dry chemicals. 

Source: Pomroy and Carigiet [1995]. 
32 

The flame cutting/welding spark/slag/flame source caused 

fires usually involving welders' clothing or oxyfuel/grease 

(grease embedded in the equipment's mechanical components). 

However, in at least two instances sparks/hot slag/flames caused 

methane ignitions followed by large fires (which on one 

occasion required firefighting interventions and mine/section 

evacuation and sealing), in six cases undetected hot slag caused 

coal belt fires, in one instance undetected hot slag caused a 

storage facility fire, in another instance undetected hot slag 

caused a large fire that required firefighting intervention and 

mine evacuation and sealing followed by a methane explosion, 

and in another instance undetected hot slag caused a coal chute 

smoldering fire, which, upon water application, produced a 

flashback accompanied by a gas explosion (causing one fatality). The spontaneous combustion/hot coal fires, accompanied in two instances by methane explosions, usually were 

detected late (by gas sampling, smoke, or coal removal) due to 

lack of continuous and early combustion gas/smoke detection 

systems. This source caused fires involving goblines, sealed 

and abandoned areas, coal silos, coal chutes, dust collectors, and 

beltlines. Forty-eight of the mobile equipment hydraulic 

fluid/fuel fires and 12 equipment electrical fires (the latter 

occurred mostly in underground coal mines) became large fires, 

which required 24 firefighting interventions (5 interventions by 

mine rescue teams in underground coal mines and

19 interventions by fire brigades and fire departments at surface 

coal operations) because of continuous flow of fluid/fuel from 

the pumps due to engine shutoff failure, lack of an emergency 

line drainage system (the flow of pressurized fluids entrapped in 

the lines was not affected by the engine shutoff operation), 

difficulty in activating available emergency systems at ground 

level, or lack of effective and rapid local firefighting response 

capabilities. (Fire-resistant hydraulic fluid is not required for 

equipment use at surface coal operations.) During these fires,on 

at least seven occasions the cab was suddenly engulfed in 

flames, probably due to the ignition of flammable vapors and 

mists that penetrated the cab. Of note is that most of the hydraulic fluid/fuel fires were caused when hydraulic fluids 

sprayed onto equipment hot surfaces; subsequently, these fires 

involved the fuel lines. In all, 10 pieces of equipment involved 

in fires had machine fire suppression systems. Dual activation 

(six activations) of machine fire suppression and engine shutoff 

systems temporarily succeeded in abating the fires, which 

reignited due to the flow of fluids embedded in the lines. 

The number of fires show decreases followed by increases 

during the five time periods. The number of fire injuries decreased during most of the periods (an increase is seen only 

during 1994–1995), accompanied by a decline in employees' 

working hours throughout the periods and an increase in coal 

production during most of the periods. The Irr and Frr values 

follow patterns similar to those shown by the injury and fire 

values (see table 39 and figure 13). 

The major findings for each coal mining category are 

discussed below. 

1. In underground coal mines, 87 fires occurred; 27 of the 

fires caused 34 injuries (Ewhr = 1,003 × 106

 hr, Irr = 0.007, CP 

= 4,008 × 106

 st, Frr = 0.022, LWD = 208). The leading 

ignition source (table 1) was electrical short/arcing (28 fires or 

32% with 17 injuries) involving electrical power and cable 

systems, power circuits, breakers, belt transformers, grounded 

wires and cables, batteries, high-voltage boxes, generators, 

rectifiers, and mobile equipment electrical cable systems. This 

was followed by the flame cutting/welding spark/slag/flame 

source (18 fires or 21% with 10 injuries); conveyor belt friction 

involving pulleys, drives, rollers, idlers, and bearings (16 fires 

or 18% with 4 injuries); and spontaneous combustion (15 fires 

or 17%). The flame cutting/welding spark/slag/flame ignition 

source caused fires usually involving welders' clothing or 

oxyfuel/grease (grease embedded in the equipment's mechanical 

components). However, in one instance sparks/hot slag/flames 

caused a methane ignition followed by a large fire, which 

required firefighting intervention and mine/section evacuation 

and sealing. In another instance, undetected hot slag caused a 

large coal fire, which required firefighting intervention and mine 

evacuation and sealing followed by a methane explosion. The 

spontaneous combustion ignition source caused fires involving 

goblines and sealed and abandoned areas, which were 

accompanied in two instances by methane explosions. In all, 

five fires destroyed or heavily damaged equipment (including 

two pieces of mobile equipment) because of failure of other 

firefighting methods, late fire detection, undetected fires, or fire 

size. Thirty-six fires were detected late by smoke, and two fires 

were undetected. 

Of note is that a large number of fires caused by electric 

short/arcing, belt friction, and spontaneous combustion sources 

were detected long after the fire had started due to lack of 

continuous and early combustion gas/smoke detection systems. 

By contrast, 12 of the mobile equipment electrical fires (which 

in at least one instance affected the hydraulic lines) and 

1 hydraulic fluid fire became large fires shortly after they 

started. Five of these fires required mine rescue team interventions because of unavailability of effective machine fire 

suppression systems, lack of an emergency hydraulic line 

drainage system (the flow of pressurized fluids entrapped in the 

lines was not affected by the motor deenergization operation), 

or lack of effective and rapid local firefighting response capabilities. Three pieces of mobile equipment involved in fires had 

machine fire suppression systems. Dual activation (two activations) of machine fire suppression and motor deenergization 

systems succeeded in temporarily abating the fires. However 

the flames reignited, fueled by the fluids entrapped in the lines. 

Upon mine/section evacuation (required 30 times), mine 

rescue teams (required 25 times), which were greatly hindered 

by intense smoke in reaching the fire location, fought the mobile 

equipment fires and other fires with dry chemical, rock dust, and 

water. In two instances, foam was also used. However, five 

fires destroyed or heavily damaged equipment. Thirteen times 

mine/section sealing/flooding/CO2/N2 gas injections were 

required. 

The equipment most often involved in fire injuries included 

electrical cable systems, voltage boxes, mobile equipment, 

oxyfuel torches, beltlines, drives, and pulleys. The most common locations where fire injuries occurred were electrical 
33 

power, pump, and charging stations, mobile equipment working 

areas, flame cutting/welding areas, trolley track and transportation areas, and belt entries. 

A comparison of underground coal mine fire data for 

1978–1992 [Pomroy and Carigiet 1995] and 1990–1999 shows 

that during the latter period fire fatalities declined dramatically 

from a yearly average of 2 to 0. However, 27 of the 1978–1992 

fire fatalities occurred during a single fire caused by an 

overheated air compressor. There was also a decline in the 

number of fires (from a yearly average of 10.8 to 8.7) and a 

small increase in fire injuries (from a yearly average of 2.9 to 

3.4), accompanied by a slight increase in coal production (from 

a yearly average of 356 × 106

 to 401 × 106 st). Other comparisons show that during both periods similar methods of 

detection and suppression were used. Very few fires were 

detected by gas sampling, CO/smoke belt fire detection systems, 

or mine-wide monitoring systems. 

Fires and fire injuries show decreases followed by increases 

during the five time periods. This was accompanied by a 

decline in employees' working hours throughout the periods and 

an increase in coal production during some of the periods. The 

Irr and Frr values follow patterns similar to those shown by the 

injury and fire values (see table 2 and figure 1). 

2. At surface of underground coal mines, 65 fires occurred; 

13 of the fires caused 12 injuries and 1 fatality (Ewhr = 97 × 106 

hr, Irr = 0.025, LWD = 6,206). The leading ignition sources 

(table 1) were hydraulic fluid/fuel sprayed onto equipment hot 

surfaces (11 fires or 17%), flame cutting/welding spark/slag/ 

flames (11 fires or 17% with 1 injury), spontaneous 

combustion/hot coal (11 fires or 17%), and electrical short/ 

arcing (4 fires or 6%). Twenty ignition sources were unknown. 

In all, 20 fires destroyed or heavily damaged equipment 

(including two pieces of mobile equipment) because of failure 

of other firefighting methods, late fire detection, undetected 

fires, or fire size. Eighteen fires were detected late, and 20 were 

undetected. The flame cutting/welding spark/slag/flame source 

caused fires usually involving welders' clothing or

oxyfuel/grease (grease embedded in the equipment's mechanical 

components). However, in one instance sparks/hot slag caused 

a methane ignition followed by a large fire, and in two other 

instances undetected hot slag caused coal belt fires. The 

spontaneous combustion/hot coal fires were usually detected 

long after the fire had started due to lack of continuous and early 

combustion gas/smoke detection systems. Three mobile equipment hydraulic fluid/fuel fires became large fires, which required fire department interventions because of the continuous 

flow of fluid/fuel from the pumps due to engine shutoff failure, 

lack of an emergency hydraulic line drainage system (the flow 

of pressurized fluids entrapped in the lines was not affected by 

the engine shutoff operation), difficulty in activating available 

emergency systems at ground level, or lack of effective and 

rapid local firefighting response capabilities. In at least two 

instances flames erupted in the cab, probably because of the 

ignition of flammable vapors and mists that penetrated the cab. 

Two pieces of mobile equipment involved in fires had machine 

fire suppression systems. Dual activation (one activation) of 

machine fire suppression and engine shutoff systems failed to 

temporarily abate the fires because of the flow of fluids 

entrapped in the lines. Fire departments (required in at least six 

instances) fought the mobile equipment fires and other large 

fires with foam, dry chemical powder, and water. 

The equipment most often involved in fire injuries included 

oxyfuel torches, heaters, and mobile equipment. The most common locations where fire injuries occurred were flame 

cutting/welding, maintenance, and mobile equipment working 

areas and charging stations. 

The number of fires and fire injuries show decreases 

followed by increases during the five time periods, accompanied 

by a decline in employees' working hours throughout the 

periods. The Irr values follow patterns similar to those shown 

by the injury values (see table 11 and figure 5). 

3. At surface coal mines, 215 fires occurred; 94 of the fires 

caused 93 injuries and 1 fatality (Ewhr = 729 × 106

 hr, Irr 

= 0.026, CP = 6,355 × 106 st, Frr = 0.034, LWD = 8,141). The 

leading ignition sources (table 2) were hydraulic fluid/fuel 

sprayed onto equipment hot surfaces (76 fires or 35% with 

22 injuries), flame cutting/welding spark/slag/flames (59 fires or 

27% with 44 injuries), spontaneous combustion/hot coal 

(21 fires or 10%), and flammable liquid/refueling fuel on hot 

surfaces (18 fires or 8% with 7 injuries). Three ignition sources 

were unknown. In all, 13 fires destroyed or heavily damaged 

equipment (including six pieces of mobile equipment) because 

of failure of other firefighting methods, late fire detection, 

undetected fires, or fire size. Twenty-eight fires were detected 

late, and 13 were undetected. The flame cutting/welding spark/ 

slag/flame source caused fires usually involving welders' clothing or oxyfuel/grease (grease embedded in the equipment's 

mechanical components). However, on four occasions undetected hot slag caused a coal belt ignition, and in one instance 

undetected hot slag caused a coal chute smoldering fire, which, 

upon application of water, produced a flashback accompanied 

by a gas explosion (causing one fatality). The spontaneous 

combustion/hot coal fires were usually detected long after the 

fires had started (by smoke or coal removal) due to lack of 

continuous and early combustion gas/smoke detection systems. 

Forty-two of the mobile equipment hydraulic fluid/fuel fires 

became large fires, which required at least 15 fire brigade and 

fire department interventions because of the continuous flow of 

fluid/fuel from the pumps due to engine shutoff failure, lack of 

an emergency hydraulic line drainage system (the flow of 

pressurized fluids entrapped in the lines was not affected by the 

engine shutoff operation), difficulty in activating available 

emergency systems at ground level, or lack of effective and 

rapid local firefighting response capabilities. On at least five 

occasions the cab was suddenly engulfed in flames, forcing the 

operators to exit under hazardous conditions, probably due to 

the ignition of flammable vapors and mists that penetrated the 

cab. Five pieces of equipment involved in fires had machine 

fire suppression systems. Dual activation (three activations) of 

machine fire suppression and engine shutoff systems succeeded 

in temporarily abating the fires; however, the flames reignited, 

fueled by the flow of fluids entrapped in the lines. Fire brigades 

and fire departments, which were required in at least 
34 

26 instances, fought the 15 equipment fires and other large fires 

with foam, dry chemical powder, and water. 

The ignition sources causing most of the fire injuries were 

flame cutting/welding spark/slag/flames (44 injuries), hydraulic 

fluid/fuel sprayed onto equipment hot surfaces (22 injuries), 

flammable liquids on hot surfaces (7 injuries), and heat sources (7 

injuries). The equipment most often involved included oxyfuel 

torches, mobile equipment, and heaters. The most common 

locations where fire injuries occurred were flame cutting/welding 

areas, mobile equipment working areas, and maintenance areas. 

Fires and fire injuries decreased during most of the periods 

(an increase is seen during 1994–1995). This was accompanied 

by a decline in employees' working hours throughout the periods 

and an increase in coal production during most of the periods. 

The Irr and Frr values follow patterns similar to those shown by 

the injury and fire values (see table 20 and figure 8). 

4. At coal preparation plants, 91 fires occurred; 23 of the 

fires caused 25 injuries (Ewhr = 241 × 106

 hr, Irr = 0.021, LWD 

= 198). The leading ignition sources (table 2) were spontaneous 

combustion/hot coal (15 fires or 17%), flame cutting/welding 

spark/slag/flames (15 fires or 17% with 8 injuries), hydraulic 

fluid/fuel sprayed on equipment hot surfaces (10 fires or 11% 

with 6 injuries), and conveyor belt friction (9 fires or 11% with 

1 injury). In all, 13 fires destroyed or heavily damaged equipment (including four pieces of mobile equipment) because of 

failure of other firefighting methods, late fire detection, or 

undetected fires. Thirty-two fires were detected late by smoke, 

and seven fires were undetected. The flame cutting/welding 

spark/slag/flame source caused fires usually involving welders' 

clothing or oxyfuel/grease (grease embedded in the equipment's 

mechanical components). However, in one instance undetected 

hot slag caused a storage facility fire. The spontaneous 

combustion/hot coal fires were detected long after they had 

started (usually by coal removal, gas sampling, or smoke) due 

to lack of continuous and early combustion gas/smoke detection 

systems. Two of the hydraulic fluid/fuel fires became large fires 

because of the continuous flow of fluid/fuel from the pumps due 

to engine shutoff failure, lack of an emergency hydraulic line 

drainage system (the flow of pressurized fluids entrapped in the 

lines was not affected by the engine shutoff operation), 

difficulty in activating available emergency systems at ground 

level, or lack of effective and rapid local fire response 

capabilities (none of the equipment involved in fires had a 

machine fire suppression system). In at least two instances, the 

cab was suddenly engulfed in flames, forcing the operators to 

exit under hazardous conditions, probably due to the ignition of 

flammable vapors and mists that penetrated the cab. Fire 

brigades and fire departments (required in at least nine 

instances) fought the equipment fires and other large fires with 

foam, dry chemical powder, and water. 

The equipment most often involved in fire injuries included 

oxyfuel torches, mobile equipment, heaters and maintenance 

equipment, and dust collectors and samplers. The most common 

locations where fire injuries occurred were flame cutting/ 

welding areas, mobile equipment working areas, maintenance 

areas, and dust collector areas. 

Fires decreased during most of the periods (an increase is 

seen during 1998–1999). The data on fire injuries show decreases followed by increases during the periods, accompanied 

by a decline in employees' working hours throughout the 

periods. The Irr values follow patterns similar to those shown 

by the injury values (see table 24 and figure 11). 

CONCLUSIONS
 

During 1990–1999, a total of 458 fires occurred in all coal 

mining categories; 157 of those fires caused 164 injuries and 

2 fatalities. The greatest number of fires and fire injuries 

occurred at surface mines, which also had the highest risk rate 

values. A total of 66 firefighting interventions were required. 

Of these, there were 25 mine rescue team interventions 

in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department 

interventions at all surface operations, including 19 mobile 

equipment interventions. In all, 50 fires destroyed or heavily 

damaged equipment (including 16 pieces of mobile equipment) 

because of failure of other firefighting methods, late fire 

detection, undetected fires, or fire size. A total of 114 fires were 

detected late by smoke, and 42 fires were not detected. 

In the future, coal mine fires might be prevented or detected 

and extinguished at their earliest stage by adopting

existing/improved technologies and/or by developing new 

technologies. Several strategies for reducing the number of fires 

and fire injuries follow. 

1. Adopt existing/improved safety procedures and develop 

new technologies for flame cutting/welding operations. Require 

safety training for welders (including contractors) working in 

gaseous environments. 

At all coal operations during 1990–1999, flame cutting/ 

welding operations caused 102 fires (22% of total fires with 

69 injuries). These fires usually involved welders' clothing or 

oxyfuel/grease (grease embedded in the equipment's mechanical 

components). However, in two instances sparks/hot slag/flames 

caused methane ignitions followed by large fires (one of these 

fires required firefighting interventions and mine/section/facility 

evacuation and sealing), in six cases undetected hot slag caused 

coal belt fires, in one instance undetected hot slag caused a 

storage facility fire, in another instance undetected hot slag 

caused a large coal fire that required firefighting intervention 

and mine evacuation and sealing followed by a methane 

explosion, and in another instance undetected hot slag caused a 

coal chute smoldering fire, which, upon water application, 
35 

produced a flashback accompanied by a gas explosion (causing 

one fatality), which required firefighting interventions and 

mine/section evacuations. By adopting existing/improved safety 

procedures, the flame cutting/welding fires due to the ignition 

of oxyfuel/grease might be prevented. By developing new technologies to contain sparks/slag, the flame cutting/welding fires 

due to sparks and hot slag might also be prevented. 

2. Adopt existing/improved inspection programs for mobile 

equipment hydraulic, electrical, and fuel systems. Adopt an 

optimal ground level location for the activation of emergency 

systems. Develop new emergency technologies for engine/pump 

shutoff, hydraulic line drainage, line safeguards, and fire barriers. Develop rapid equipment/cab fire detection and effective 

fire prevention/suppression systems. Develop effective and rapid 

local firefighting capabilities. Schedule more frequent fire emergency preparedness training for equipment operators. 

At all coal operations during 1990–1999, there were 98 

(21% of total fires with 29 injuries) mobile equipment hydraulic 

fluid/fuel fires (mostly at surface operations) and 12 equipment 

electrical fires in underground mines, which in at least one 

instance affected the hydraulic lines. Most of the hydraulic 

fluid/fuel fires became large fires because of the continuous 

flow of fluid/fuel from the pumps due to engine shutoff failure, 

flow of pressurized fluids entrapped in the hydraulic lines (not 

affected by the engine shutoff operation), difficulty in activating 

emergency systems at ground level, or lack of effective and 

rapid local firefighting capabilities. Of note is that most of the 

hydraulic fluid/fuel fires were caused when hydraulic fluids 

sprayed onto equipment hot surfaces; subsequently, these fires 

involved the fuel lines. In at least seven instances the cab was 

suddenly engulfed in flames, probably due to the ignition of 

flammable vapors and mists that penetrate the cab during the 

spraying of pressurized hydraulic fluid onto equipment hot 

surfaces. Also, most of the mobile equipment electrical fires became large fires because of unavailability of effective machine 

fire suppression systems, lack of an emergency hydraulic line 

drainage system, or lack of effective and rapid local firefighting 

capabilities. In all, 10 pieces of mobile equipment involved in 

fires had machine fire suppression systems. Dual activation (six 

activations) of machine fire suppression and engine shutoff 

systems succeeded in abating the fires, but the flames reignited, 

fueled by the flow of fluids entrapped in the lines (not affected 

by the engine, or motor, shutoff operation). 

By adopting existing/improved mobile equipment inspection 

programs, hydraulic line and electrical cable wear and tear 

might be detected early, thereby preventing hydraulic fluid/fuel 

and electrical cable fires. By adopting an optimal location for 

ground level activation of machine fire suppression and engine 

shutoff systems, these emergency operations might be 

performed safely and in a timely manner, thus stopping the 

continuous flow of fluid/fuel from the pumps. By developing 

new technologies for the emergency draining of pressurized 

fluids entrapped in lines, the hydraulic fluid fires might not 

reignite, thus allowing the operators to exit the cab safely. By 

developing/adopting cab fire detection and cab fire inerting/ 

suppression systems, the cab fires might not occur. By 

preparing local miners to fight mobile equipment fires, when 

detected, with large, contained quantities of suppressant agents 

on vehicles for ease of deployment to the fire site, these fires 

might be extinguished in their early stage. 

3. Adopt existing/improved continuous and early combustion gas/smoke detection systems. 

At all coal operations during 1990–1999, there were 71 (16% 

of total fires) spontaneous combustion/hot coal fires involving 

goblines, sealed and abandoned areas, coal silos, coal chutes, dust 

collectors, and beltlines. The spontaneous combustion/hot coal 

fires were usually detected late due to lack of continuous and 

early combustion gas/smoke detection systems; however, twice 

they were accompanied by methane explosions. By adopting 

existing continuous and early combustion gas/smoke detection 

systems, the spontaneous combustion/hot coal fires might be 

detected and suppressed at their earliest stage. 

4. Adopt existing/improved technologies to monitor 

equipment operations. 

At all coal mining operations during 1990–1999, there were 

30 fires (7% of total fires with 6 injuries) caused by the 

operational failure of beltlines, drives, and pulleys. By adopting 

existing/improved technologies to monitor equipment operations, failures might be detected early, thereby preventing these 

types of equipment fires. 

ACKNOWLEDGMENT

The author thanks Kimberly A. Mitchell, Program Operations Assistant, NIOSH Pittsburgh Research Laboratory, for 

computerizing the tables and figures in this report. 

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Inc., Somerset, CO, January 26, 1999. Arlington, VA: U.S. Department of 

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MSHA [2000]. Injury experience in coal mining, 1999. Denver, CO: U.S. 

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IC 9426. 
Delivering on the Nation’s Promise:

Safety and health at work for all people
 

Through research and prevention
 

For information about occupational safety and health topics contact NIOSH at: 

1–800–35–NIOSH (1–800–356–4674) 

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SAFER • HEALTHIER • PEOPLETM 

DHHS (NIOSH) Publication No. 2004–167