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FINAL REGULATORY IMPACT AND REGULATORY
FLEXIBILITY ANALYSIS OF FINAL RULE
30 CFR PARTS 7, 36, 70, AND 75

STANDARDS FOR UNDERGROUND COAL MINES U.S. Department of Labor
Mine Safety and Health
Administration
Office of Standards,
Regulations, and Variances

October 1996


I. EXECUTIVE SUMMARY

INTRODUCTION AND SUMMARY

The Mine Safety and Health Administration (MSHA) is establishing standards and regulations for diesel-powered equipment in underground coal mines. Coal mine operators began to introduce diesel-powered equipment into underground mines in the early 1970's. The number of diesel units operating in underground coal mines has increased from approximately 150 in 1974, to over 2,900 units operating in 173 mines in 1995. MSHA projects that the number of diesel units operating in underground coal mines could increase to approximately 4,000 in 250 underground coal mines by the year 2,000. The final rule sets tests and specifications for MSHA approval of diesel engines and related components to ensure that they operate cleanly and do not introduce fire or explosion hazards in the confined, potentially gassy underground coal mine environment. In addition, the final rule requires that diesel engines be properly maintained and that miners workplaces be checked for elevated concentrations of hazardous diesel exhaust emissions. The final rule also sets standards for safe fuel handling and storage, and requires certain proven safety features for diesel-powered equipment ranging from methane monitors to canopies to protect equipment operators from cave-ins.

Executive Order 12866 requires that regulatory agencies assess the cost and benefits of any rule having major economic consequences for the national economy, an individual industry, a geographic region, or a level of government. The Regulatory Flexibility Act (5 U.S.C 601 et seq.) similarly requires regulatory agencies to consider the rule's impact on small entities. For the purposes of the Regulatory Flexibility Act, MSHA has traditionally, by policy, determined a small entity to be one employing fewer than 20 employees. MSHA's final regulatory flexibility analysis, discussed in detail later in part V, comports with the requirements of the Regulatory Flexibility Act. MSHA has determined that these standards and regulations would not have a major effect of $100 million or more on the economy.

INDUSTRY CHARACTERISTICS
For many years diesel-powered equipment has been used in underground metal and non-metal mines. During the past 20 years such equipment has been increasingly used in coal mines. The number of diesel-powered equipment operating in underground coal mines has increased from 150 units in 1974 to over 2,900 units operating in 173 mines in 1995. Of these 173 mines, 158 are large mines and 15 are small mines.

BENEFITS
The final rule establishes comprehensive and integrated requirements governing diesel-powered equipment used in underground coal mines. Compliance with the rule will minimize fire, explosion, fuel handling and storage hazards. The hazards of diesel engine exhaust are minimized by design and performance standards for diesel engines and maintenance. Other safety hazards associated with the use of diesel-powered equipment in underground coal mines are also addressed.

The final rule includes tests and specifications for MSHA approval of diesel engines. These requirements will result in clean operating diesel engines appropriate for use in the confined underground mine environment, which will reduce miners' exposure to harmful emissions. The final rule sets test procedures and limits on the concentrations of carbon monoxide, oxides of nitrogen, and establishes the quantity of ventilating air necessary to dilute these exhaust contaminants to safe levels. The rule also contains tests and specifications for diesel engine components, which ensure that diesel engines are fire and explosion-proof.

The final rule also requires diesel-powered equipment to be equipped with certain basic safety features. These safety features will result in reduced fire hazards and lower risk of accidents involving diesel-powered equipment. The final rule requires fire-protection features, including fuel, hydraulic, and electrical system protections; and properly designed, installed and maintained fire suppression systems. Diesel-powered equipment is also required to have basic safety features, such as brakes and lights. In addition, the rule extends to diesel-powered equipment safety measures that apply to electric-powered equipment and that have proven to protect miners from cave-ins and explosions.

The final rule also addresses diesel-powered equipment when in operation underground. The rule provides for a systematic approach to the clean and safe operation of diesel-powered equipment. To accomplish this, the final rule sets standards for ventilation of diesel-powered equipment, routine sampling for toxic exhaust gases in the work place, and the use of low sulfur diesel fuel to minimize emissions, and requires that maintenance be performed by trained personnel to keep diesel equipment in proper operating condition.

To ensure that the hazards associated with diesel fuel usage in the underground mine environment are properly controlled, the final rule includes requirements for the underground storage, transportation and dispensing of diesel fuel. Design, capacity, and dispensing requirements are set for diesel fuel storage, as well as safety precautions and construction requirements for underground storage facilities and areas, including automatic fire suppression systems. These provisions will reduce the risk of fires involving diesel fuel.

The final rule also extends several longstanding safety requirements for electric equipment to diesel-powered equipment. The final rule requires certain diesel equipment to be installed with methane monitors, providing miners with critical protection against methane explosions. The final rule also requires cabs and canopies to be installed on certain diesel-powered equipment, protecting miners from the dangers of roof and rib falls in the underground mine environment.

Part III of this analysis contains a more detailed discussion of the specific safety and health hazards of diesel-powered equipment, and the benefits derived from the final rule with respect to those hazards.

COST OF COMPLIANCE
The compliance costs associated with the standards directly impact two industry groups: manufacturers of diesel-powered mining equipment; and operators of underground coal mines. Part 7, subparts E, and F relates to manufacturer costs and Parts 70 and 75 relate to operator costs. The total compliance costs of the rule is estimated to be about $10.35 million per year, of which mine operators will incur about $10.3 million per year and manufacturers will incur about $50,450 per year.

The per year cost of $10.3 million for mine operators consist of $4.9 million of annualized cost plus $5.4 million of annual costs. Of the $10.3 million, large mine operators will incur about $10.1 million, which consist of $4.8 million of annualized costs and $5.3 million of annual costs. Of the $10.3 million, small mine operators will incur about $210,800, which consist of $92,300 of annualized costs and $118,500 of annual costs. Manufacturers will incur about $50,450 per year. The $50,450 consist of $15,900 of annualized costs and $34,550 of annual costs.

REGULATORY FLEXIBILITY CERTIFICATION
Pursuant to the Regulatory Flexibility Act of 1980, MSHA has analyzed the impact of these rules upon small businesses. MSHA has concluded that the standards and regulations for diesel-powered equipment in underground coal mines will not have a significant adverse impact upon a substantial number of underground small coal mines. MSHA has not exempted small mine operators from any provision of the final rule and has determined that small mines would benefit from the provisions of the final rule. MSHA has included provisions to minimize costs, e.g. delayed effective dates, and minimal paperwork requirements, where possible.

II. INDUSTRY PROFILE

INTRODUCTION
This industry profile briefly describes the structure and characteristics of the coal mining industry. Since this final rule primarily affects underground coal mines, this section provides information concerning the number of underground coal mines, the estimated number of employees, and other industry market characteristics. This section also provides some of this information specifically for the mines currently using diesel-powered equipment. Finally, the chapter concludes with estimates of the numbers of types of diesel-powered equipment used in underground coal mines.

PROFILE OF THE U.S. COAL INDUSTRY
Bituminous coal accounts for the largest share of all U.S. coal production. With respect to 1994 coal production estimates: about 90 percent came from bituminous and subbituminous coal; and the remainder came from lignite and anthracite coal. The principle market for U.S. coal is the electric utility industry. The 1994 coal production was allocated as follows: 79 percent was sold to electric utilities; 7 percent was exported; 3 percent was used in coke plants; and the balance was used in other industrial residential, commercial and transportation sectors.

COAL PRODUCTION
The United States produced 1.03 billion tons of coal in 1994 of which about 399.1 million tons were mined in underground mines [1, p. 7]. Using the 1994 U.S. price of $19.41 a ton [1, p. 150] for the average price of coal, the Mine Safety and Health Administration (MSHA) estimates that the total value of coal production was about $20 billion and the value of underground coal production was about $7.7 billion. In 1994, approximately 38 percent of the coal mined in the U.S. was extracted using underground mining techniques. Underground coal mines are characterized in two ways: (1) by the method through which the seam is accessed (i.e., shaft, drift, or slope) and (2) by the mining system used to extract the coal (i.e., conventional, continuous, or longwall mining). Longwall mining can recover between 80 and 85 percent of the coal, whereas, room and pillar methods of mining that use conventional and continuous methods, can recover about 50 to 60 percent of the coal.

Table II-1 below provides industry information for 1995 on the number of underground coal mines and miners by number of miners employed per mine. The data in Table II-1 are preliminary estimates. For purposes of this final Regulatory Impact Analysis (RIA) and the final Regulatory Flexibility Act (RFA), coal mining

TABLE II-1 DISTRIBUTION BY SIZE OF
UNDERGROUND COAL MINES IN THE U.S.
1995 - PRELIMINARY DATA

Detail Number
of
Mines
Percent
of
All Mines
Number
of
Miners
Percent
of All
Miners
Small Mines
1 - 19 466 43.5 4,630 8.6
Large Mines
> 20 606 56.5 49,370 91.4
Total Mines 100 56.5 54,000 100

    Source: U.S. Department of Labor, Mine Safety and Health Administration. Denver Safety and Health Technology Center. Coal 1995 Size-Group Report (Quarters 1 thru 4 \ Preliminary Data) - CM441, cycle 95/086. Unpublished data. April, 1996. [2]
operations have been separated into two categories: (1) those operations having 20 or more employees; and (2) those operations classified as small businesses, having fewer than 20 employees. Over the past 20 years, for rule making purposes, MSHA has consistently used this small mine definition. This rulemaking has been consistent with the Small Business Act and the Regulatory Flexibility Act. MSHA sought and received early public participation in the rulemaking. In addition, MSHA has included alternatives which both respond to commenters' concerns and minimize burdens on the mining public. As will be discussed in the various sections of the preamble, MSHA's final Regulatory Flexibility Analysis meets the Regulatory Flexibility Act's requirements particularly as it covers small businesses. As can be seen in Table II-1, 43.5 percent of all underground coal mines (466 mines out of 1,072 mines) are small mines that employ about 8.6 percent of all underground coal miners (4,630 miners out of 54,000 miners). In addition, about 91.4 percent of all underground miners are employed by 56.5 percent of mines that employ at least 20 miners.

PROFILE OF MINES USING DIESEL-POWERED EQUIPMENT
Diesel-powered equipment has been operating in underground mines in Europe since the 1930's. The use of diesel-powered equipment expanded in 1947 when British Coal mines were nationalized. Diesel-powered equipment is used extensively in western European countries, as well as, Canada, Australia, South Africa and the countries formerly known as the USSR.

In the United States, diesel-powered equipment was first used in 1951. As of 1978, there were about 4,400 diesel-powered units in use in underground U.S. mines, however, a large majority of these units were operating in non-coal mines. Most recent data concerning diesel-powered equipment in underground coal mines is provided by MSHA's Approval and Certification Center (ACC). Based on manufacturing dates of diesel-powered equipment in underground coal mines obtained from the ACC's September 1995 diesel inventory, Table II-2, shows that in almost 45 years the use of diesel-powered equipment in underground coal mines has increased from less than 100 units as of the end of 1975 to 2,349 units as of the end of September of 1995. The ACC's diesel inventory also shows that there are 579 diesel machines that list no manufacturing date, thus, there are actually, 2,928 diesel-powered machines currently in underground coal mines (2,349 + 579 = 2,928).

There are 173 underground coal mines that use diesel-powered equipment, 158 are large mines and 15 are small mines. Underground coal mines that use diesel-powered equipment tend to be large. Only 15 out of 173 ( or 8 percent) of the mines which use diesel-powered equipment employ fewer than 20 miners, whereas, 437 out of 1,022 (or 42.8 percent) of all underground coal mines employ fewer than 20 miners. Underground coal mines that use diesel-powered equipment are primarily in Kentucky, Illinois, Utah, Virginia, Colorado and Maryland.

TABLE II-2 NUMBER OF DIESEL-POWERED EQUIPMENT PIECES
IN UNDERGROUND COAL MINES IN THE UNITED STATES
1952 THROUGH 9/30/95

       Year               Equipment       
1952 thru 1975 76
1976 97
1977 141
1978 188
1979 228
1980 303
1981 441
1982 589
1983 652
1984 739
1985 864
1986 1,023
1987 1,151
1988 1,266
1989 1,417
1990 1,609
1991 1,781
1992 1,959
1993 2,103
1994 2,297
9/30/95 2,349
No Date 579
    Source: U.S. Department of Labor, Mine Safety and Health Administration.
    Office of Standards, Regulations, and Variances. 1995.

DEFINITIONS
A definition of terms used throughout this impact analysis is listed below.

Permissible Equipment is a completely assembled machine or accessory for which a formal MSHA approval has been issued. This equipment operates mainly in the part of the underground mine which has a potentially methane rich atmosphere. Such equipment is normally found in the working or production area of the mine. The working area of a mine is defined as the area inby the last open cross-cut. Thus, permissible equipment is also referred to as "inby" equipment.

Nonpermissible Equipment is equipment that does not operate in the part of the mine which has a potentially methane rich atmosphere. Thus, nonpermissible equipment refers to all machines that are not classified as permissible. Nonpermissible equipment is also referred to as "outby" equipment.

Explosion-proof means that a component or subassembly is so constructed and protected by an enclosure and/or flame arrester(s) that if a flammable mixture of gas is ignited within the enclosure it will withstand the resultant pressure without damage to the enclosure and/or flame arrester(s). Also, the enclosure and/or flame arrester(s) shall prevent the discharge of flame or ignition of any flammable mixture that surrounds the enclosure.

Heavy Duty Equipment is mainly production type equipment that is intended to move rock or coal or other heavy loads, such as, longwall components, as a normal part of their duty cycle. This equipment is also of the type that is used continually during a shift. Although heavy duty equipment can be classified as either permissible or nonpermissible, it is generally permissible equipment.

Light Duty Equipment is equipment that is not intended to move rock or coal, or perform other activities normally associated with production equipment. Although, light duty equipment could carry loads similar to heavy duty equipment, light duty equipment would likely operate infrequently and for short periods of time during the shift. Although light duty equipment can be classified as either permissible or nonpermissible, it is generally nonpermissible equipment.

Permanent Underground Diesel Fuel Storage Facility is a facility designed and constructed to remain at one location for an extended period of time for the storage or dispensing of diesel fuel, and which does not move as mining progresses.

Temporary Underground Diesel Fuel Storage Facility is an area of the mine provided for the short term storage of diesel fuel in a fuel transportation unit and which moves as mining progresses.

Diesel Fuel Transportation Unit is a wheeled vehicle used to transport a diesel fuel tank that can be either self-propelled or not self-propelled.

Nonself-propelled Equipment is equipment that may be moved frequently and is constructed or mounted to facilitate such movement. This equipment is towed.

Diesel Power Package is a diesel engine and the attached safety components, such as flame arrestor, spark arrestor, surface temperature controls, shut down systems, and exhaust cooling system that make a diesel engine explosion-proof and reduce the engine surface temperatures to safe levels.

PROFILE OF DIESEL-POWERED EQUIPMENT USED
IN UNDERGROUND COAL MINES

As seen in Table II-3, of the 2,928 pieces of diesel-powered equipment in use as of the end of September 1995, there are 567 (20 percent) permissible pieces and 2,361 (or 80 percent) nonpermissible pieces. Approximately 98 percent of all diesel-powered equipment is found in large mines. The average small underground coal mine using diesel-powered equipment has about 3 pieces of that equipment, of which 1 is permissible and 2 are nonpermissible. The average large underground coal mine using diesel-powered equipment has about 18 pieces of that equipment, of which 3 are permissible and 15 are nonpermissible.

In general, the types of mining equipment that are diesel-powered and might be found in an underground coal mine, consist of the following types of equipment: air compressor; ambulance; crane truck; ditch digger; foam machine; forklift; generator; gradeR; haul truck; load-haul-dump machine; longwall retriever; locomotive; lube unit; mine sealant machine; personnel car; hydraulic pump machine; rock dusting machine; roof/floor drill; shuttle car; tractor; utility truck; water spray unit and welder.

TABLE II-3

CHARACTERISTICS OF MINES
THAT USED DIESEL-POWERED EQUIPMENT
(AS OF 9/30/95)

      Detail             Large             Small             Total      
Diesel Equipment
Permissible 542 25 567
Nonpermissible 2,336 25 2,361
Total 2,878 50 2,928
Average Mine
Permissible 3 1   
Nonpermissible 15 2   
Total 18 3   
    Source: U.S. Department of labor, Mine Safety and Health Adm.
    Office of Standards, Regulations, and Variances. 1995

The numbers of permissible and nonpermissible diesel-powered equipment by year of manufacture are presented in Table II-4. Of the 2,928 pieces in Table II-4, 80 percent (2,349) of the diesel-powered pieces of equipment have been identified by a manufacturing date; a manufacturing date cannot be associated with 579 pieces. Of the 2,349 pieces, 2,121 (or 90 percent) have been manufactured since 1980. With respect to permissible diesel-powered equipment, 358 of the 462 pieces of diesel-powered equipment for which a date of manufacture is known (or 77 percent) have been manufactured since 1980. With respect to nonpermissible diesel-powered equipment, 1,763 of the 1,887 pieces of equipment for which a date of manufacture is known (or 93 percent) have been manufactured since 1980.

TABLE II-4
PERMISSIBLE AND NONPERMISSIBLE
DIESEL-POWERED EQUIPMENT BY YEAR OF MANUFACTURE (THRU 9/30/95)

    Year         Permissible         Nonpermissible         Total    
1995 3 49 52
1994 11 183 194
1993 8 136 144
1992 15 163 178
1991 28 144 172
1990 22 170 192
1989 24 127 151
1988 20 95 115
1987 19 109 128
1986 29 130 159
1985 25 100 125
1984 28 59 87
1983 14 49 63
1982 30 118 148
1981 47 91 138
1980 35 40 75
1979 22 18 40
1978 19 28 47
1977 12 32 44
1976 12 9 21
1975 12 13 25
1974 7 9 16
1973 6 4 10
1972 4 0 4
1971 0 1 1
1970 0 3 3
1969 0 1 1
1968 1 1 2
1960 9 2 11
1958 0 1 1
1954 0 1 1
1952 0 1 1
No Date 105 474 579
    Source: Dept. of Labor, Mine Safety and Health Administration,
    Office of Standards, Regulations and Variances. 1995

PART II - REFERENCES

1. Dept. of Energy/Energy Information Agency. DOE/EIA-0584(94).
     Coal Industry Annual 1994. October 1995.

2. U.S. Department of Labor, Mine Safety and Health Administration.
    Denver Safety and Health Technology Center.
    Coal 1995 Size-Group Report (Quarters 1 thru 4/Preliminary
    Data) - CM441, cycle 95/086. Unpublished data. April,
    1996.

III. BENEFITS EVALUATION

INTRODUCTION
Fires and explosions are the primary safety hazards associated with the use of diesel-powered equipment in underground coal mines. Diesel-powered equipment, which has an internal combustion engine, increases the potential for fire and explosion when used in the underground coal mining environment, where there are combustibles such as coal dust, and methane. High surface temperatures on diesel-powered equipment can be ignition sources for hydraulic fluid, lubricating oil, diesel fuel, and coal dust. The operation of the engine also presents an ignition source for explosive concentrations of methane that naturally occur and may accumulate in the underground mine environment. Diesel-powered equipment can be large and move very rapidly. In many ways, the operational hazards of diesel-powered equipment are similar to those of electrical-powered equipment.

The handling and storage of diesel fuel underground also present serious fire hazards. Fires can instantaneously occur from the spilling of fuel on hot surfaces or malfunctioning electric components. In addition, any fire in an underground coal mine can rapidly develop into a catastrophic situation if the fire spreads to areas where large quantities of diesel fuel are being stored or to the coal seam. Similar hazards arise from spillage of diesel fuel when it is transported throughout the mine and when diesel machines are refueled. In addition, diesel fuel can leak from tanks in storage facilities or areas that are damaged or not properly maintained.

Fires and explosions in underground coal mines have resulted in catastrophic loss of life and property. In 1984, a fire in the Wilberg Mine in Utah claimed the lives of 27 miners. In 1989, an explosion at the Pyro Mining Company William Station Mine in Kentucky killed 10 miners. Seventeen miners narrowly escaped a fire in 1990 at the Mathies Mine in Pennsylvania, and 7 miners were injured during fire fighting efforts. In 1992, 8 miners died in an explosion at the Southmountain No. 3 Mine in Virginia. For the period from 1980 through July of 1996, underground coal mine fires and explosions have claimed the lives of 119 miners.

As the consequences of these fires and explosions graphically demonstrate, the underground coal mine environment is conducive to the propagation of any ignition source into a disastrous event.

The 1984 Wilberg Mine fire started with a remote generator which overheated and caught fire. The fire quickly spread to the highly combustible surrounding coal, creating an uncontrollable fire. The fire and lethal products of combustion spread rapidly throughout the mine, trapping and killing 27 miners. The 1989 William Station Mine explosion was found to most likely have been caused by a cutting torch which ignited a body of methane gas that had accumulated in the miners' workplace. The ensuing explosion instantly killed the 10 miners working in the vicinity.

In addition to their victims, fires and explosions in underground coal mines also put many other lives at risk. At such disasters mine rescue teams, typically composed of 7 individuals, make courageous efforts to save the miners', and stabilize the mine sufficiently to recover the victims. In the 1990 Mathies Mine fire, two mine rescue teams were fighting a fire, caused when electrical arcing ignited the surrounding coal. An ignition during these fire fighting efforts injured 7 rescue team members. All together, this coal mine fire endangered the lives of the 17 miners who were trapped, and the 14 mine rescue team members fighting the fire.

The 1992 Southmountain No. 3 Mine explosion likewise endangered numerous mine rescue teams seeking to recover the eight miners killed in an explosion initiated by a cigarette lighter. For more than a week, several times a day, mine rescue teams entered this underground coal mine in attempts to stabilize the conditions sufficiently to recover the miners bodies. Fortunately, there was no further loss of life.

In addition to the legal, medical and other expenses that are incurred, losses from coal mine fires and explosions are also significant. The 1990 Mathies Mine fire resulted in a complete shut down of this operation, which to date has not reopened. At the time of the fire, 408 miners where employed on two coal producing shifts working 5-days a week. Average production was 6,500 tons of coal per day (1.625 million tons annually). At the 1994 price of $19.41 per ton, the lost revenue annually exceeds $30 million.

Even a non-fatal mine fire at a small operation can have serious financial impact. For example, a 1983 fire on a diesel-powered utility truck at the Emery Mining Corporation's Beehive Mine in Utah rapidly spread throughout the mine. None of the 10 miners working at the mine were killed, but the operation was closed resulting in the loss of $3.1 million in annual coal revenues.

Powered haulage and machinery accidents also significantly contribute to deaths and injuries among miners. In the confined underground coal mine environment, increasingly powerful high-speed diesel-powered equipment can quickly crush and kill or seriously injure miners. This equipment is used to rapidly transport miners and supplies, and power large rock and coal moving machines. A total of 230 deaths in underground coal mines from 1980 through July of 1996 were related to machinery and powered haulage accidents.

Diesel engines also produce harmful exhaust emissions including carbon monoxide, oxides of nitrogen, and particulate matter. The operation of diesel-powered equipment in the underground mine environment creates a workplace with the potential for very high concentrations of these contaminants.

In 1980 there were about 300 pieces of diesel-powered equipment in underground coal mines in the United States. Ten years later, in 1990, some 1,600 units of diesel-powered equipment were in use in underground coal mines and, as of October 1995, the total rose to 2,900 such machines. Currently, MSHA has very limited regulations which address only in a rudimentary way hazards associated with diesel-powered equipment used in underground coal mines. As the use of diesel-powered equipment continues to increase in underground coal mines, the need to address the specific safety and health hazards associated with such equipment increases.

The Secretary of Labor convened a federal advisory committee in 1988 to evaluate and make recommendations for the safe and healthful use of diesel-powered equipment in underground coal mines. In accordance with the Mine Act, the advisory committee was composed of persons with broad backgrounds and collective expertise in underground mining, diesel equipment, and occupational health and safety. The advisory committee presented a report to the Secretary, which highlighted potential fire hazards associated with the use of diesel-powered equipment, hazards associated with uncontrolled handling and storage of diesel fuel underground, and the acute and long term effects of exposure to diesel exhaust on the health of miners. The advisory committee agreed to a three-fold approach to address hazards associated with diesel-powered equipment: use of MSHA's existing equipment approval process to require that diesel engines be properly designed for use in the underground coal mine environment; rules for the safe use of diesel-powered equipment; and measures to protect the health of miners from the harmful effects of diesel emissions. The advisory committee report formed the basis of MSHA's proposed rule. The final rule addresses the hazards identified in the advisory committee's report and the proposal, and includes requirements that will reduce those hazards.

SUMMARY OF THE FINAL RULE'S BENEFITS
The final rule establishes comprehensive and integrated requirements governing diesel-powered equipment used in underground coal mines. Compliance with the rule will minimize fire, explosion, fuel handling and storage hazards. The hazards of diesel engine exhaust are addressed by design and performance standards for diesel engines and maintenance. Other safety hazards associated with the use of diesel-powered equipment in underground coal mines are also addressed.

The final rule includes tests and specifications for MSHA approval of diesel engines. The expected benefit of these requirements is clean operating diesel engines appropriate for use in the confined underground mine environment, which will reduce miners' exposure to harmful emissions. The final rule sets test procedures and limits on the concentrations of carbon monoxide, oxides of nitrogen, and establishes the quantity of ventilating air necessary to dilute these exhaust contaminants to safe levels. The rule also contains tests and specifications for diesel engine components, which ensure that diesel engines are fire and explosion-proof.

The final rule also requires diesel-powered equipment to be equipped with certain basic safety features. The expected benefit of these requirements is reduced fire hazards and lower risk of accidents involving diesel-powered equipment. The final rule requires fire-protection features, including fuel, hydraulic, and electrical system protections; and properly designed, installed and maintained fire suppression systems. Diesel-powered equipment is also required to have basic safety features, such as brakes and lights. In addition, the rule extends to diesel-powered equipment safety measures that have applied to electric-powered equipment and that are proven to protect miners from cave-ins and explosions.

The final rule also addresses diesel-powered equipment when in service underground. The rule provides for a systematic approach to the clean and safe operation of diesel-powered equipment. To accomplish this, the final rule sets standards for ventilation of diesel-powered equipment, routine sampling for toxic exhaust gases in the work place, and the use of low sulfur diesel fuel to minimize emissions, and requires that maintenance be performed by trained personnel to keep diesel equipment in proper operating condition.

To ensure that the hazards associated with diesel fuel usage in the underground mine environment are properly controlled, the final rule includes requirements for the underground storage, transportation and dispensing of diesel fuel. Design, capacity, and dispensing requirements are set for diesel fuel storage, as well as safety precautions and construction requirements for underground storage facilities and areas, including automatic fire suppression systems. The expected benefit of these rules is the reduction in the risk of fires involving diesel fuel.

The final rule also extends several longstanding safety requirements for electric equipment to diesel-powered equipment. The final rule requires certain diesel equipment to be installed with methane monitors, providing miners with critical protection against methane explosions. The final rule also requires cabs and canopies to be installed on certain diesel-powered equipment, protecting miners from the dangers of roof and rib falls in the underground mine environment.

Below is a more detailed discussion of the specific safety and health hazards of diesel-powered equipment, and the benefits derived from the final rule with respect to those hazards.

SAFETY HAZARDS RELATED TO THE USE OF DIESEL-POWERED EQUIPMENT

FIRES AND EXPLOSIONS ASSOCIATED WITH DIESEL-POWERED EQUIPMENT

Mining experience with diesel-powered equipment has shown that this equipment poses a substantial fire risk. On diesel equipment, the surface temperature of the engine's exhaust components will normally be above the autoignition temperature of combustible materials, particularly the diesel fuel and hydraulic fluid found on the equipment. If these combustible materials contact the hot engine surfaces, they are likely to ignite. Fires and explosions may also be caused by sparks from a diesel engine, or when methane gas is ingested into an engine, resulting in the ignition of methane in the work place. Diesel-powered equipment presents a different and unique fire risk than other ignition sources in the mining environment. Other types of underground coal mine fires may smolder for some time before a flame develops. However, with many diesel-powered equipment fires open flaming develops very rapidly and is more difficult to extinguish than a smoldering fire.

CHARACTERISTICS OF DIESEL-POWERED EQUIPMENT FIRES IN MINES

MSHA examined 331 diesel-equipment related fires in American mines that occurred between 1970 and February 1992 [1]. The data indicated that: a significant number of fires occurred on mobile diesel-powered equipment in mines; these fires frequently occurred on heavily worked equipment; and the most frequent cause of fire was a fuel source, such as hydraulic fluid or fuel, coming into contact with a hot surface or an electrical ignition source. This information comes from MSHA's accident reports from 1972 through 1991; MSHA coal mine inspector reports for the years 1970 through February 1992; and from "Summary of Underground Diesel Fires" by Pomroy. While many of the fires did not occur in underground coal mines, they involved large diesel-powered equipment presenting similar hazards.

Nearly all of these fires lasted more than 30 minutes (MSHA's Part 50 regulations require only fires of more than 30 minutes to be reported, unless an injury occurred). Of the 331 fires, 151 occurred in metal and nonmetal mines (91 in surface mines and 60 in underground mines) and 180 occurred in coal mines (170 in surface mines and 10 in underground mines). For much of the period reflected in this data large numbers of diesel-powered equipment were not being operated in underground coal mines. Diesel-powered equipment is used in much greater numbers at surface mines compared to underground coal mines.

Table III-1 shows the cause, ignition source, and fuel source for those fires where such determinations could be made. A cause could be positively determined for 116 of the 331 fires (or 35 percent). In many cases the damage was so severe that the cause of the fire could not be pin-pointed. Concerning these 116 incidents, 46 (or 40 percent) were associated with faults in the vehicle hydraulic systems, 24 (or 21 percent) were associated with faults in the vehicle electrical systems, and 46 (or 40 percent) were due to other causes.

Of the 331 fires, there were 206 (or 62 percent) for which an ignition source was found. With respect to these 206 cases, 131 (or 64 percent) involved a hot surface (e.g., the exhaust manifold, engine, or turbocharger) as the ignition source, 35 (or 17 percent) involved electrical faults, and 40 (or 19 percent) involved other sources.

There were 202 of the 331 cases (or 61 percent) for which the fuel ignited by the ignition source was reported. Concerning these 202 incidents, 131 (or 65 percent) involved either hydraulic fluid or diesel fuel, 27 (or 13 percent) involved oil,

TABLE III-1
FIRES IN AMERICAN MINES

        Fires For Which a Cause Could be Determined        
Fires Hydraulic
System Fault
Electrical
System Fault
Other
Causes
 
116 46 24 46  
 
Fires For Which an Ignition Source Could be Determined
Fires Hot Surfaces Electrical Other
Sources
 
206 131 35 40  
 
Fires For Which a Fuel Source Could be Determined
Fires Hydraulic Fluid
or Diesel Fuel
Oil, Grease
or Fuel Other
Than Diesel
Insulation
or Rubber
Other
Substances
202 131 27 10 34
    Source: Mine Safety and Health Administration, Approval and Certification Center, Division of Mechanical and Material Safety, Triadelphia, West Va. 26059. 1992. [1].
grease or fuels other than diesel, such as natural gas or propane, 10 (or 5 percent) involved insulation or rubber, and 34 (or 17 percent) involved other substances.

MSHA's examination of the 331 diesel-powered equipment fires in American mines extended to fires that occurred from 1970 to 1992. Since then at least 10 fires, lasting 30 minutes or longer, have occurred on diesel-powered equipment at American mines. A continuing trend is seen in the cause of these fires, mainly leaking hydraulic oil or diesel fuel spraying on hot engine components. Fires due to short circuits in electrical systems also continue.

In addition to the data from American mines, MSHA examined accident reports from the Ministry of Labor, Province of Ontario, Canada, that contain information on diesel-powered equipment fires in Ontario's underground mines. The examination of the Ontario data identified 289 fires on diesel-powered equipment that occurred between the years 1984 through 1992. Approximately 2,600 pieces of diesel-powered equipment are in use in Ontario underground mines, which is the same number in use in American underground coal mines. These mines are of the type that MSHA would classify as metal and nonmetal non-gassy mines. The equipment and machine types involved in the fires are similar to those used in U.S. underground coal mines. Also, fires of any duration (not just greater than 30 minutes) were reported in the Ontario data. The Ontario data confirms the finding in American mines that diesel-powered machines subjected to heavy duty usage pose significant risk of fire.

Ignition sources identified in the Ontario data were similar to those mentioned in the data noted above: for about 34 percent of the fires (99 fires) the ignition source was attributed to some part of the engine or exhaust system; for 43 percent (123 fires) the ignition source was related to an electrical component; for about 19 percent the ignition source was related to the braking system; and 4 percent (12 fires) had miscellaneous ignition sources.

INJURIES CAUSED BY DIESEL-POWERED EQUIPMENT FIRES

There was an injury in 170 of the 331 cases of fire involving diesel-powered equipment in American mines, and in one case a fatality occurred. Of these 171 cases, 78 were in metal and non-metal mines (65 in surface mines and 13 in underground mines) and 93 were in coal mines (85 in surface mines and 8 in underground mines). Injuries that required days off from work occurred in 123 (or 72 percent) of the 170 cases. In 147 of the 171 cases (or 86 percent) the injuries included an individual being burned and/or being injured in attempting to get off or jump off the machine that was on fire. The final rule sets forth requirements for safety features on certain diesel-powered equipment that would prevent fires. The final rule addresses the ignition and fuel sources that have caused the fires and injuries noted above. Although, many of these fires occurred in underground metal mines rather than coal mines, they are typical of diesel-powered equipment fires. Injury data was not available with respect to the Canadian fire data.

OTHER TYPES OF SAFETY HAZARDS
INVOLVING DIESEL-POWERED EQUIPMENT

Other safety hazards are associated with the use of diesel-powered equipment in addition to fire hazards. The speed and mobility typical of diesel machines can introduce hazards in the underground mine environment. Operating diesel-powered equipment at a high rate of speed coupled with the uneven roadway conditions that are frequently found in many underground mines can cause the operator to lose control of the equipment.

Diesel-powered equipment, like other types of equipment found in underground coal mines, poses safety risks for the equipment operator and the miners who work near the equipment. These hazards include pinch points, runaway hazards from inadequate brakes, and unexpected movement of the machine resulting from unconventional or inadequate controls. These risks are particularly pronounced on diesel-powered mining equipment because of its large size and speed. Safety features that address these hazards are typically found on commercial and industrial type equipment and are applied to diesel-powered mining equipment in this rule.

BENEFITS OF THE RULE CONCERNING SAFETY HAZARDS

The final rule provides safety benefits to miners by addressing the four principal areas of risk resulting from the introduction of diesel-powered equipment into underground coal mines. These four areas are: fire and explosion hazards of diesel engines, fires due to improper storage and handling of diesel fuel underground, equipment features needed to prevent personnel injury, and maintenance of diesel-powered equipment to assure its continued safe operation. These areas are discussed separately below.

BENEFITS OF THE RULE ADDRESSING DIESEL POWER PACKAGES

Subpart F of the final rule amends existing part 7 and establishes requirements for diesel power packages to assure the safe use of diesel-powered equipment. A diesel power package is a diesel engine and the attached safety components, such as flame arrestor, spark arrestor, surface temperature controls, shut down systems, and exhaust cooling system that make a diesel engine explosion-proof and reduce the engine surface temperatures to safe levels. These requirements benefit miners by reducing the risk of fires and explosions on diesel-powered equipment used in areas of the mine where potentially high concentrations of methane can accumulate. Part 7, and new subpart F, require manufacturer or third-party laboratory testing of diesel-powered equipment for approval in lieu of MSHA testing.

BENEFITS OF THE RULE ADDRESSING FUEL HANDLING AND STORAGE

Sections 75.1902 through 75.1906 set requirements that together comprise a comprehensive approach to addressing the safety hazards that arise from introducing diesel fuel in underground coal mines. Limitations are set on the amount of fuel that can be stored underground. Also, standards are set for the locations where fuel can be stored; the facilities where fuel can be stored; and the methods of storage, transportation, and dispensing of fuel. The Ontario fire data indicated that 10 fires resulted during the fueling of diesel-powered equipment. These requirements benefit miners by minimizing the risk of accidents during refueling.

In order to protect against diesel fuel spills and unsafe storage practices, § 75.1902 addresses how diesel fuel can be safely stored underground, sets the quantity of fuel that can be safely stored, and specifies safe locations for diesel fuel storage facilities and areas. Section 75.1903 establishes construction and design requirements for diesel fuel storage facilities or areas, including standards for containment in case of a fuel spill. Together, these requirements reduce fire hazards. They will also provide increased protection in the event of a fire through the use of noncombustible construction materials and doors which will close to confine the fire and retard its spread. This section also requires permanent underground diesel fuel storage facilities to be equipped with an automatic fire suppression system. Prohibition against cutting and welding near diesel fuel storage facilities and areas are also set by the final rule.

Section 75.1904 includes standards for the design of diesel fuel tanks and safety cans to protect against leakage from tanks and their associated components, in order to reduce the risk of fire from spilled fuel, and in case of a fire controlled the release of vapors through emergency venting. Also, tanks and their associated components are required to be protected against the corrosive mine environment and damage from collision by machines running into them in order to avoid the potential fire or explosion hazard that could result from spilled fuel.

Section 75.1905 addresses the inherent risks of spillage and fire when dispensing diesel fuel. These requirements of the final rule address the circumstances under which diesel fuel is dispensed underground, minimizing the occasion for spills. This section also prohibits the use of compressed gas in dispensing diesel fuel, a method that could lead to large amounts of fuel being spilled. Further, diesel machines are prohibited from being refilled with the engine running. The high exhaust component temperatures of operating diesel engines provide an ignition source. This ignition source presents a serious risk during refueling, which can be readily eliminated by shutting off the engine.

One method used to transport diesel fuel underground is through a pipeline from a surface storage facility to an underground location. Such facilities hold as much as 30,000 gallons of diesel fuel. Section 75.1905-1 addresses the hazards of diesel fuel stored in a surface facility that could unintentionally be discharged underground in an uncontrolled manner. This section sets requirements designed to prevent such a spill, by establishing safety requirements for the piping system, specifications for operating controls, requirements for isolating the piping systems from damage and potential ignition sources, and precautions for containing a unintentional fuel discharge.

Section 75.1906 sets requirements concerning the safe transportation of diesel fuel in order to reduce the risk of fuel spillage and fire underground. The final rule limits the amount of fuel that can be transported in mobile units, and specifies protections for fuel containers during transport. Nonself-propelled diesel fuel transportation units that are equipped with electrical components, such as pumps or lights, present a potential ignition source. Under the final rule, these units must have an automatic fire suppression system capable of responding to a fire, which could involve the diesel fuel. Diesel fuel transportation units are also required to be parked in protected, well ventilated storage facilities and areas when not in use. The final rule places limitations on the use of safety cans containing diesel fuel. These limitations are in response to commenters who were concerned about the uncontrolled use of small quantities of diesel fuel throughout the mine.

Fire suppression systems are necessary in permanent storage facilities because of the large quantity of diesel fuel present and the fire hazards associated with fuel storage and transfer operations. Automatic actuation of these systems is necessary to extinguish fires that may occur when no miner is in the area. Section 75.1912 establishes standards for fire suppression systems for permanent underground diesel fuel storage facilities. The rule addresses the design, installation, and maintenance of these systems. A properly designed, installed and maintained fire suppression system can extinguish a fire at an early stage of its development when it is easiest to fight.

BENEFITS OF THE RULE ADDRESSING EQUIPMENT SAFETY FEATURES

Equipment safety features are contained in §§ 75.1907 and 75.1909 through 75.1911. Section 75.1907 establishes the basic requirement that only diesel equipment approved under existing regulations may be used in areas where coal is being extracted and where explosive concentrations of methane may exist. Such approved equipment is designed to be explosion-proof and contains basic safety features. This aspect of the final rule consistent with current practices in underground coal mines. It also conforms the safety requirements for diesel-powered equipment with existing safety requirements for electric-powered equipment. Section 75.1907 sets a compliance schedule, ranging from 24 to 36 months, for upgrading the safety features of existing approved diesel-powered equipment, requiring, for example, fire suppression and brake systems.

For equipment that operates in other locations of the mine where methane accumulation is not expected to be a hazard, § 75.1907 sets a 12 to 36 month compliance schedule for incorporating machine safety features, such as brakes, fire suppression features, electrical system protections, and protections against other fire hazards associated with diesel engines. The compliance schedule set by § 75.1907 provides realistic time frames for incorporating safety features that address the hazards of using diesel-powered equipment.

Section 75.1909 establishes design and performance requirements for safety features on diesel-powered equipment in areas of the mine where coal is not being extracted and explosive levels of methane gas are not expected to accumulate. This section establishes uniform requirements that address common hazards inherent with all types of diesel-powered equipment. In addition, the final rule includes requirements that are tailored to the unique hazards that are associated with different classes of diesel-powered equipment used in underground coal mines. The benefit of this aspect of the rule is to minimize the fire risk associated with diesel-powered equipment by controlling possible fuel and ignition sources. In addition, the final rule requires that other safety features be incorporated on the equipment to address the mobility, speed and size of diesel-powered equipment.

Under § 75.1909 all diesel-powered equipment must have an approved engine. As noted elsewhere, the benefit of this aspect of the final rule is basically clean low emission engines which minimize miner exposure to harmful levels of exhaust gas. In order to address the fire hazard associated with this equipment, all the machines would have to have a substantially constructed fuel system designed to minimize leaks, the unintentional release of fuel, and be separated from hot surfaces and electrical components that might serve as ignition sources. Similar fire protection is required for hydraulic tanks and lines which could leak and provide fuel for a fire. Guarding to protect the hydraulic, electric and fuel lines, when they pass near rotating parts, is also required. Fires have occurred when fluid from a severed hydraulic or fuel line leaks onto a hot surface of the machine or onto broken electric lines. To further address this hazard, this section contains a requirement that a means be provided to prevent the spray from ruptured hydraulic or lubricating oil lines from contacting hot surfaces. Fires originating in this manner have occurred frequently on diesel-powered equipment used in other mining applications and have produced some of the most serious equipment fires. The expected benefit of these requirements is to minimize the risk of fires by preventing fuel and ignition sources from coming into contact.

While all diesel-powered equipment used in underground coal mines is required to be provided with the features discussed above, other requirements are tailored to specific classes of equipment. The equipment classes are based on how the equipment is used and the fire hazard that the equipment usage presents. For example, automatic fire suppression systems are required on heavy duty equipment, which poses the greatest risk of fire because of its high engine surface temperatures. Nonself-propelled equipment, such as air compressors or electrical generators, poses a fire risk similar to that of heavy duty equipment and, therefore, is also required to have an automatic fire suppression system. The hot engine surfaces of light-duty equipment still present an ignition source, but the equipment as a whole does not present as great a fire risk as heavy duty equipment. Under the final rule, this equipment can have either a manual or automatic fire suppression system. All diesel-powered equipment must be provided with an appropriate fire extinguisher under the final rule.

Section 75.1909 requires certain safety features to address the hazards associated with the mobility, speed, and size of diesel-powered equipment. The benefit of these requirements is to enable the equipment operator to maintain control of the machine, and avoid injury to the equipment operator and other miners. Section 75.1909 requires diesel-powered machines with steering, brakes, and accelerator pedals to have these controls arranged in the same manner as standard automobile orientation, thus reducing the risk of confusion and loss of vehicle control. Diesel-powered equipment also must be equipped with appropriate service and parking brakes, to provide the equipment operator with adequate stopping ability over the machine and assurance that it will not move if left parked on a grade. The brake system requirements are different for heavy duty and light duty equipment, consistent with the way the equipment is used. Other safety features presently required on electrical equipment, such as lights, reflectors, and audible warning devices, are required to be installed on diesel-powered equipment.

Also, all diesel equipment is required to be attended when it is operating, because of the inherent fire hazards in the form of fuel and ignition sources. The presence of an operator provides an additional level of safety. The operator can act to correct any problem that develops with the machine, take steps to extinguish a fire in its incipient stages, or warn other miners of a fire.

Section 75.1910 addresses requirements for electrical systems for equipment that operates in locations of the mine where methane accumulation is not a hazard. Electrical systems on this type of equipment have frequently caused fires. The expected benefit of this section is to minimize the risk of electrical system fires by requiring short circuit protection and electrical overload protection, and to protect electrical system components from damage.

Section 75.1911 establishes requirements for fire suppression systems installed on diesel-powered equipment and fuel transportation units. The rule addresses the design, installation and maintenance of fire suppression systems. Properly designed, installed and maintained fire suppression system can extinguish a fire at an early stage of its development when it is easiest to fight.

The final rule also extends several longstanding safety requirements for electric equipment to diesel-powered equipment. The final rule requires methane monitors on diesel-powered machines used to extract or load coal. Methane monitors, which have been required for many years on certain types of electric equipment, provide an initial warning, then automatically shut down the equipment, when methane concentrations approach explosive levels. This prevents any ignition sources from the machine's operation setting off a potentially catastrophic methane explosion. The final rule ensures that miners working around diesel equipment are protected from fire and explosion hazards to the same extent as miners working around electric equipment.

Methane monitors are a critical line of defense against disaster. In 1981, 15 miners were killed in a methane explosion in an underground coal mine in Colorado when a methane monitor that had not been properly installed failed to shut down the machine lighting circuit. The lighting circuit ignited high levels of methane that had accumulated in the area. Methane monitors on electric equipment have contributed to the reduction in methane and coal dust explosions in underground coal mines over the last 50 years. Between 1947 and 1970 (the year that the Coal Mine Health and Safety Act took effect) 901 miners were killed in methane and coal dust explosions in underground coal mines. Between 1971 and 1994, this number was 133. Methane monitors played a key role in reducing the number of these fatalities.

Under the final rule, certain types of diesel-powered equipment must be equipped with substantially constructed cabs or canopies to protect miners operating such equipment from roof falls and rib and face rolls. Cabs and canopies, which have been required on certain underground electric equipment since 1972, provide equipment operators with very effective protection from the hazards of roof and rib falls and collisions with the mine roof and ribs. Since 1972, there have been more than 280 documented cases where miners' lives were saved in massive roof falls because they were protected by cabs or canopies. Some mine operators, recognizing the clear safety benefits of cabs and canopies, have already installed them on diesel equipment in their mines. Cab and canopy requirements for diesel equipment will protect equipment operators against very serious hazards in underground coal mines.

BENEFITS OF THE RULE ADDRESSING MAINTENANCE,
TRAINING, AND OPERATIONS

The performance of the best designed equipment will deteriorate without proper maintenance. Concern about inadequate maintenance of safety features of diesel-powered equipment was frequently expressed by commenters to this rule. These same commenters stressed the importance of having maintenance performed by fully qualified personnel. Successful programs are in place through existing regulations specifying the required maintenance of electrical equipment. These programs also specify the training and qualification of persons performing maintenance on electric equipment.

Section 75.1914 establishes maintenance requirements for diesel-powered equipment used in underground coal mines. Inadequate maintenance of diesel-powered equipment can result in the creation of fire or explosion hazards. As part of the maintenance requirements, this section requires that diesel-powered equipment be maintained in safe condition. The expected benefit of this requirement is to minimize the chance for an explosion or fire. The rule also requires that machine operators inspect equipment for safety hazards before placing it in operation. In addition, weekly exams and tests of other features of diesel machines are required. These exams or tests will be conducted by trained personnel in accordance with established maintenance procedures. These measures will ensure that machine defects that could endanger miners are recognized and corrected. These new requirements extend to diesel equipment the same basic maintenance that has been proven successful for electric equipment.

The training of maintenance personnel is an essential part of any effort to control safety hazards associated with diesel machines. Some commenters stated that untrained personnel failed to properly maintain diesel equipment creating hazardous operating conditions. Section 75.1915 contains requirements for the comprehensive training and qualification of persons who maintain and repair diesel-powered equipment. The expected benefit of requiring adequate training of persons performing maintenance is an increased assurance that safety and health hazards are recognized and that repair work is performed correctly.

Starting aids, such as ether in aerosol cans are used in cold weather to help start diesel engines. Section 75.1913 establishes requirements for the proper use and storage of starting aids. The expected benefit of this section is to prevent improper use of starting aids which could create a flashback of fire that can ignite a flammable mixture of methane in the air.

Much of the diesel-powered equipment in use in underground coal mines is the same type used in over-the-road or industrial applications. This equipment can travel at much higher speeds than electrical equipment designed specifically for underground mining. Unlike electrical equipment, diesel-powered equipment does not need to be connected to the mine electrical system with a power cable. Section 75.1916 addresses the hazards associated with the increased speed and mobility of diesel machines by requiring that operating speeds be consistent with visibility and condition of roadways, roadways be kept in good condition, and that traffic rules be standardized at each mine.

HEALTH HAZARDS RELATED TO THE USE OF DIESEL-POWERED EQUIPMENT

Underground mining creates confined areas where supplying healthful air for miners to breath is a major concern. The health of miners in the confined area of underground mines is affected by toxic gases and dust that may be present. Diesel engines used in underground mines emit toxic gases and particulate matter in their exhaust. If these pollutants are not controlled, the operation of diesel engines in underground coal mines can result in the overexposure of miners to toxic substances recognized as harmful and which can produce long term adverse health effects.

EXPOSURE TO GASEOUS CONTAMINANTS IN DIESEL EXHAUST

Diesel engines, like all internal combustion engines, produce large quantities of exhaust gas. A portion of this exhaust gas consist of harmful gases and particulate matter. The harmful gases consist mostly of carbon monoxide and the oxides of nitrogen. Other harmful gases, such as sulfur dioxide, are present in smaller amounts. The toxic nature of these gases is recognized and the levels to which workers can be exposed without harmful effects have been established by various health organizations. The American Council of Governmental Industrial Hygienists (ACGIH) sets exposure levels for many gases and other substances found in work places. MSHA has adopted into its regulations many of the exposure levels established by the ACGIH for gases found in mine environment.

MSHA already has regulations in place that limit miner exposure to carbon monoxide, the oxides of nitrogen and other gases found in diesel exhaust, because these gases can be liberated from other sources. For example, carbon monoxide is produced by the decomposition of mining timbers, the oxides of nitrogen are produced by the detonation of explosives used in mining, and sulfur dioxide is produced by naturally occurring sulfur in the coal. However, miners must be protected from exposure to harmful levels of these gases when produced by diesel engines.

Diesel engines do not produce the same quantities of toxic gases under all conditions of operation. When diesel engines work hard producing higher horsepower, they burn more fuel, produce more exhaust gas, and that exhaust gas contains higher levels of toxic gases. In the mining environment, ventilating air dilutes these gases to acceptable levels and carries away the toxic gases. Consequently, the most hazardous conditions occur when multiple diesel engines are operated at high power levels in areas of restricted ventilation.

The most common complaints of miners involve unloading diesel-powered coal haulage equipment and installing and removing extremely heavy mining equipment. These operations are typically carried out with several diesel-powered machines operating simultaneously at high engine power levels in concentrated areas. These complaints have been borne out through MSHA field studies that have identified levels of carbon monoxide and the oxides of nitrogen that are above the acceptable levels.

The complete record of the diesel rulemaking incudes numerous references to serious health hazards from exposure to diesel exhaust. The Advisory Committee report referenced the Committee's discussions and miners' panel presentations related to health effects other than respiratory diseases. Several studies were discussed which showed increased symptoms related to diesel exposure. These include dizziness, eye and olfactory irritation, nausea, drowsiness, headaches, skin rashes and other problems. While these effects may be difficult to measure, there is repeated testimony from miners at both the advisory committee meetings and the diesel public hearings concerning theses adverse health effects. Individual miners testified, many of whom stating that they required medical treatment.

Miners at the public hearing reiterated both the acute and chronic effects of exposure to diesel exhaust. The incidence of acute effects, e.g. eye, nose and throat irritations, according to miners reports, are difficult to measure under current MSHA illness reporting regulations. Obviously, chronic effects are more dependent upon long-term studies. There were two medical doctors on the advisory committee, including the chairman. They stated that "it was uncertain what the long term effects of repeated headaches, nausea, or conjunctivitis are, but such effects would affect the overall health of workers." (Adv. Comm., report, p. 70).

EXPOSURE TO PARTICULATE MATTER IN DIESEL EXHAUST

In addition to producing harmful exhaust gases, diesel engines produce large quantities of particulate matter, which appear as smoke. Diesel particulate matter is a complex mixture of solid materials formed during the combustion process, which are small enough to be breathed deep into the lungs. Although extensive research has been conducted into the adverse health effects of exposure to diesel particulate matter, the scientific community has not yet reached a consensus on the level of particulate matter to which miners can be exposed without adverse health effects. In their report, the Secretary's Diesel Advisory Committee noted that diesel exhaust, including its particulate matter, presented a health hazard to humans. While proposing no specific exposure level, the Advisory Committee recommended control of diesel particulate underground through a combination of measures.

BENEFITS OF THE RULE CONCERNING HEALTH HAZARDS

The final rule provides health benefits to miners by requiring action in four major areas to limit miner exposure to gaseous and particulate emissions from diesel engines. The final rule would require that only clean burning engines using low sulfur diesel fuel be used in mines to minimize emissions, that adequate ventilation be provided in areas where diesel equipment is being used, that sampling be conducted to confirm that miners are not being exposed to harmful emissions, and that proper engine maintenance be performed by qualified persons. The rule integrates requirements in these four areas to provide the required level of health protection without making any single requirement overly burdensome.

BENEFITS OF THE RULE ADDRESSING APPROVED DIESEL ENGINES
AND LOW SULFUR FUEL

For underground coal mines, clean burning engines are critically important. Unlike electrically powered equipment, diesel engines emit exhaust containing toxic gases that can be harmful to miners. Inappropriately designed engines can pollute the mine atmosphere excessively, elevating toxic gases to levels that can not be controlled with normal ventilation practices. To achieve the objective of clean burning, appropriately designed engines part 7, subpart E, sets performance standards and testing requirements for all engines used in underground coal mines. The expected benefit of this rule is a limit on the amounts of harmful gases which are produced and the determination of the quantity of ventilating air required to dilute these gases to safe levels. The testing also determines the amount of diesel particulate in the exhaust, allowing the cleanest engines to be selected for use in underground coal mines. Manufacturer or third party laboratory testing is required for approval of diesel engines in lieu of MSHA testing.

The amount of sulfur in the fuel is related to the amount of gaseous and particulate emissions produced by the engine. Section 75.1901 requires the use of the same low sulfur diesel fuel which is used by all highway trucks. The use of low sulfur fuel provides the benefit of immediately reducing emissions from diesel engines, and also promotes the use of exhaust aftertreatment technologies which can further reduce emissions.

BENEFITS OF THE RULE ADDRESSING VENTILATION

Adequate ventilation must be provided in areas of underground coal mines where diesel-powered equipment is being used to protect miners from exposure to harmful levels of exhaust contaminants. Using the minimum ventilating air requirements established for diesel engines in part 7, subpart E, a mine operator can operate diesel-powered equipment while protecting the health of miners. Sections 75.325(f) through (j) establish the quantity of ventilating air that must be provided to control exhaust contaminants from individual and multiple diesel engines to allowable exposure levels.

MSHA conducted a study of three coal mines that use diesel equipment, two in the West and one in the East, to determine representative levels of gaseous diesel exhaust emissions [2]. Although all of these mines used relatively large quantities of ventilating air, the study nonetheless found concentrations approaching ceiling values of nitrogen dioxide and carbon monoxide over the threshold limit values at various locations in the mines. This demonstrates that the air used to ventilate the mine must be distributed effectively to dilute harmful gaseous diesel exhaust contaminants. The final rule addresses this by specifying locations where a minimum air quantity must be maintained to control air quality in areas of the mine where high concentrations of exhaust gas occur. The most common miner complaints involve the build up of diesel exhaust emissions while unloading diesel-powered coal haulage equipment and installing and removing extremely heavy mining equipment. These operations are typically carried out with several diesel-powered machines operating simultaneously in areas of restricted ventilation. An expected benefit of the rule is to provide sufficient ventilating air at these locations to dilute exhaust gases to allowable levels.

The particulate produced by diesel engines is currently controlled under existing health standards limiting the amount of dust that can be in the underground coal mine atmosphere. The mine operator can use the particulate data, obtained during part 7, subpart E, engine approval, to estimate the contribution of the diesel particulate to the total mine dust level.

BENEFITS OF THE RULE ADDRESSING SAMPLING

The effectiveness of the mine operator's efforts to limit exposure of miners to the contaminants from diesel exhaust can only be evaluated by sampling the mine environment for those contaminants. Although the integrated approach of using clean burning engines and low sulfur diesel fuel to minimize emissions, providing adequate ventilation in areas where diesel equipment is being used, and performing proper engine maintenance by qualified persons is expected to maintain diesel exhaust emissions to acceptable levels, sampling must be used to confirm that miners are not being exposed to harmful emissions. The MSHA study of three coal mines supports this conclusion. This approach is needed because of frequent changes in mining conditions and variability in diesel equipment usage.

Section 70.1900 requires sampling for carbon monoxide and nitrogen dioxide at specific locations. Measurement at these locations provides the most accurate appraisal of the effectiveness of the integrated approach to controlling miner exposure to harmful emissions. Sampling is required to be performed at a time when emission levels are representative of the contribution of all equipment during normal operations and the results of sampling are available immediately to the person performing the sampling. Finally, § 70.1900(c) requires prompt corrective action, such as increased ventilation or servicing of equipment, to be taken. The expected benefit of this regulation is increased assurance that miners will not be exposed to harmful levels of diesel exhaust gas.

BENEFITS OF THE RULE ADDRESSING MAINTENANCE AND TRAINING

Diesel engine performance deteriorates with usage. Engine faults such as malfunctioning fuel injectors or dirty air filters can develop. These faults can increase the levels of harmful exhaust emissions produced by the engine. Section 75.1914 requires that diesel engines be properly maintained so that they continue to operate as clean burning engines. Additionally, weekly testing of exhaust levels of carbon monoxide required by this section will provide an indication of a problem developing with the engine and identify the need for corrective action.

The training of maintenance personnel is an essential part of any effort to control the health hazards associated with diesel engines. Some commenters stated that untrained personnel failed to properly maintain diesel engines. Section 75.1915 contains requirements for the comprehensive training and qualification of persons who maintain diesel engines. Taken together, the expected benefit of requiring that diesel engines be properly maintained by trained and qualified persons is an increased assurance that diesel engines continue to operate as clean burning engines and that miners will not be exposed to harmful levels of diesel exhaust gases.

ADDITIONAL BENEFITS OF THE RULE

Currently, MSHA regulates the use of diesel-powered equipment underground through the ventilation plan approval process and some general machine use requirements in existing regulations for underground coal mines. Some states also have regulations which either comprehensively or partially address hazards associated with the use of diesel equipment underground. Other states prohibit the use of diesel-powered equipment in underground coal mines. The final rule, will provide the benefit of uniform regulations that are specifically applicable to the use of diesel-powered equipment in underground coal mines. These uniform regulations will encourage an equitable regulatory playing field for mine operators, miners, engine and machine manufacturers, and coal producing states.

The rule allows engine and equipment manufacturers to test diesel engines and power packages for conformance to approval standards instead of the current practice of MSHA performing all testing. Engine and equipment manufacturers will benefit by gaining the flexibility to determine the most timely and economical means to have the testing completed. The rule also incorporates internationally accepted engine testing procedures. This will enable diesel engine manufacturers to test with a single set of procedures common to both the United States and foreign markets. The use of the international test procedures provides a more competitive posture for American products in foreign markets, leads to increased compatibility with international testing practices, and stimulates metric conversion.

Further, the final rule will eliminate outdated regulations in Part 31 "Diesel Mine Locomotives" and Part 32 "Mobile Diesel-powered Equipment for Noncoal Mines". Part 31 was promulgated in 1944 and has not been updated. Its requirements are inconsistent with a number of existing MSHA standards. Approvals of locomotives is used areas of the mine where permissible electrical equipment is required and have been effectively granted through the use of the Part 36 equipment approval program. Part 32 specifies requirements for approval of diesel-powered equipment but there is no existing MSHA regulation that requires the use of Part 32 approved equipment.

PART III - REFERENCES

1. Dept. of Labor/Mine Safety and Health Administration,
    Approval and Certification Center. Division of Mechanical
    and Material Safety. Triadelphia, West Va. 26059. April
    1992.

2. Mine Safety and Health Administration, Pittsburgh Health
    Technology Center, Investigation Reports P221-V127 (1982),
    P199-V105 (1981), and P206-V112 (1981).

IV. COST OF COMPLIANCE

INTRODUCTION
This chapter contains MSHA's estimates of the compliance costs associated with the final rule. The baseline for these estimated costs is current industry practices. As the rule will impose compliance costs upon both underground coal mines and diesel-powered equipment manufacturers, this analysis contains separate estimates for each of these groups. In addition, the compliance costs incurred by underground coal mines using diesel-powered equipment are differentiated into those compliance costs incurred by large coal mines and those compliance costs incurred by small coal mines.

METHODOLOGY
MSHA estimated compliance costs with the rule on a provision by provision basis, using the baseline of current industry practices. These estimated costs are the incremental (i.e., additional) costs that underground coal mine operators of diesel-powered equipment and diesel-powered equipment manufacturers will incur for compliance. Many provisions of these rules, such as approved engines and other components required for permissible diesel-powered equipment have been required by MSHA through the mine ventilation plan approval requirements. Consequently, many provisions will involve no compliance costs because underground coal mines are currently in compliance.

DATA BASES
The cost of compliance estimates are based upon several data sources. One source is the opinions, facts, and policies provided by MSHA District Office and MSHA Approval and Certification Center (ACC) personnel. Their experiences with and knowledge of underground coal mines and diesel-powered equipment provide an appropriate basis for determining current industry practices, the extent to which these practices would need to be modified for compliance with the final rules, and the cost of these modifications. Another source is public comments in response to MSHA's proposed rule. A third source is cost information directly obtained from manufacturers and distributors of diesel-powered equipment by the Office of Standards, Regulations, and Variances.

The labor costs are primarily based upon the 1994 wage rate of $18.64 an hour for coal miners reported in March 1995 by the Bureau of Labor Statistics [1, p. 97]. This rate was raised by 40 percent [2, pp. La19] to account for such fringe benefits as workers compensation, unemployment insurance, social security, medical and others. As a result, total hourly compensation is about $26. The 1993 weighted average hourly earnings for supervisory salaried engineers is $26.68 [3, p 9]. Raising this hourly wage rate by 40 percent to account for fringe benefits [4, p 3] results in a total hourly compensation of $37.35. In order to convert capital costs into annualized capital costs, a 7 percent discount rate is used.

TYPES OF COSTS
MSHA estimated: (1) Initial costs; (2) annualized costs (which are Initial costs amortized over a specific number of years); and (3) annual costs.

Initial costs consist of capital expenditures and one time costs. Capital expenditures are defined as equipment purchase costs. One time costs are costs, other than equipment costs, that are usually incurred once and do not reoccur annually. An example of a one time cost would be the costs to develop a written procedural program.

Initial costs are amortized over a specific number of years to arrive at what is called annualized costs. Initial costs are annualized in order to recognize that equipment is used over a period of years, or that a plan or program developed in one year will be used for several years. Converting an initial cost to an annualized cost changes that cost from one that does not reoccur annually to one that does reoccur annually. This conversion is done so that the annualized costs (which are converted initial costs) can be added to annual costs in order to get the cost per year of a rule that accounts for all of the costs in that rule. Annual costs are costs that normally reoccur annually. Examples of an annual cost are maintenance costs and recordkeeping costs.

SUMMARY OF COST OF COMPLIANCE ESTIMATES
The total compliance costs of the rule is estimated to be about $10.35 million per year, of which mine operators will incur about $10.3 million per year and manufacturers will incur about $50,450 per year.

Compliance Costs for Mine Operators
The $10.3 million consist of annualized cost plus annual costs. Initial costs were estimated to be $24.0 million. The $24.0 million were amortized over a specific period of time to arrive at $4.9 million of annualized costs. The $4.9 million of annualized costs were then added to $5.4 million of annual costs to arrive at $10.3 million per year.

Of the $10.3 million, large mines will incur about $10.1 million. Initial costs for large mines were estimated to be $23.5 million which were amortized over a specific period of time to be $4.8 million. The $4.8 million were then added to $5.3 million of annual costs to arrive at $10.1 million per year.

Of the $10.3 million, small mines will incur about $210,800. Initial costs for small mines were estimated to be $546,700 which were amortized over a specific period of time to be $92,300. The $92,300 were then added to $118,500 of annual costs to arrive at $210,800 per year.

Compliance Costs for Manufacturers
Of the $10.35 million, manufacturers will incur about $50,450. Initial costs for manufacturers were estimated to be $226,800 which were amortized over a specific period of time to be $15,900. The $15,900 were then added to $34,550 of annual costs to arrive at $50,450 per year.

Table IV-1 summarizes estimated costs by section for large and small mines; and Table IV-2 summarizes estimated costs by section for manufacturers.

TABLE IV - 1: UNDERGROUND COAL MINE COMPLIANCE COSTS FOR DIESEL EQUIPMENT (DOLLARS X 1,000)

Standard
or Subpart
Large and Small Mines Large Mines Small Mines
(A)
Total
[Col. +C]
(B)
Annualized
 
(C)
Annual
 
(D)
Total
[Col. E+F]
(E)
Annualized
 
(F)
Annual
 
(G)
Total
[Col. H+I]
(H)
Annualized
 
(I)
Annual
 
70.1900      ($ 59.7) $ 80.9 ($ 140.6) ($ 77.7) $ 75.8 ($ 153.5) $ 18.0 $ 5.1 $ 12.9
75.325        $ 589.0 $ 0 $ 589.0 $ 589.0 $ 0 $ 589.0 $ 0 $ 0 $ 0
75.1902      $ 39.7 $ 39.7 $ 0 $ 37.6 $ 37.6 $ 0 $ 2.1 $ 2.1 $ 0
75.1903      $ 68.5 $ 51.5 $ 17.0 $ 58.2 $ 44.7 $ 13.5 $ 10.3 $ 6.8 $ 3.5
75.1904      $ 32.7 $ 32.7 $ 0 $ 31.2 $ 31.2 $ 0 $ 1.5 $ 1.5 $ 0
75.1905      $ 2.4 $ 2.4 $ 0 $ 2.3 $ 2.3 $ 0 $ 0.1 $ 0.1 $ 0
75.1906      $ 251.8 $ 173.5 $ 78.3 $ 244.7 $ 168.8 $ 75.9 $ 7.1 $ 4.7 $ 2.4
75.1907      $ 1,610.3 $ 1,596.6 $ 13.7 $ 1,589.6 $ 1,576.4 $ 13.2 $ 20.7 $ 20.2 $ 0.5
75.1909      $ 3,028.0 $ 2,532.9 $ 495.1 $ 2,971.2 $ 2,487.6 $ 483.6 $ 56.8 $ 45.3 $ 11.5
75.1910      $ 117.4 $ 117.4 $ 0 $ 116.1 $ 116.1 $ 0 $ 1.3 $ 1.3 $ 0
75.1911      $ 1,221.3 $ 0 $ 1,221.3 $ 1,203.2 $ 0 $ 1,203.2 $ 18.1 $ 0 $ 18.1
75.1912      $ 20.0 $ 0 $ 20.0 $ 16.5 $ 0 $ 16.5 $ 3.5 $ 0 $ 3.5
75.1913      $ 9.5 $ 9.5 $ 0 $ 9.4 $ 9.4 $ 0 $ 0.1 $ 0.1 $ 0
75.1914      $ 2,769.3 $ 40.1 $ 2,729.2 $ 2,700.0 $ 36.8 $ 2,663.2 $ 69.3 $ 3.3 $ 66.0
75.1915      $ 573.9 $ 155.4 $ 418.5 $ 572.3 $ 153.9 $ 418.4 $ 1.6 $ 1.5 $ 0.1
75.1916      $ 8.7 $ 8.7 $ 0 $ 8.4 $ 8.4 $ 0 $ 0.3 $ 0.3 $ 0
                   
Total      $ 10,282.8 $ 4,841.3 $ 5,441.5 $ 10,072.0 $ 4,749.0 $ 5,323.0 $ 210.8 $ 92.3 $ 118.5
    Source: U.S. Dept. Of Labor, Mines Safety and Health Adm.,
    Office of Standards, Regulations, and Variances. 1995
TABLE IV-2
ESTIMATED MANUFACTURERS COMPLIANCE COSTS
ASSOCIATED WITH THE REGULATIONS FOR DIESEL-POWERED EQUIPMENT
IN UNDERGROUND COAL MINES

Standard Manufacturers Costs   
(A)
Total
[Col. B+C]
(B)
Annualized
 
(C)
Annual
 
Part 7 - Subpart E $42,650 $12,200 $30,450
Part 7 - Subpart F $7,800 $3,700 $4,100
Total Part 7 $50,450 $15,900 $34,550
    Source: U.S. Depart. of Labor, Mine Safety and Health Adm.,
    Office of Standards, Regulations, and Variances. 1995

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