ISSUE DATE: 5/16/2011

 

PROGRAM INFORMATION BULLETIN NO. P11-39

FROM: LINDA F. ZEILER

 Acting Director for Technical Support

 NEAL H. MERRIFIELD

 Administrator for

 Metal and Nonmetal Mine Safety and Health

 KEVIN G. STRICKLIN

 Administrator for

 Coal Mine Safety and Health

SUBJECT: Reissue of P09-38 - Information on Use of Biodiesel Fuel in 

 Underground Diesel-Powered Equipment; Availability of 

 Report

Scope

Metal and nonmetal underground mine operators, miners and miners’ representatives, 

manufacturers of diesel-powered underground mining equipment, Mine Safety and 

Health Administration (MSHA) Metal and Nonmetal enforcement personnel, MSHA 

Technical Support personnel, and other interested parties should receive this bulletin.

Purpose

MSHA is issuing this Program Information Bulletin (PIB) to provide updated 

information to the mining community on the technological feasibility of biodiesel fuels

as an effective control method for reducing miners’ exposures to diesel particulate 

matter (DPM) pursuant to Title 30 Code of Federal Regulations (30 C.F.R.) §§ 

57.5060(b)(3) and 57.5060(d) of the DPM standard.
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Information

Biodiesel is a registered fuel and fuel additive with the Environmental Protection 

Agency (EPA) that meets clean diesel standards established by the California Air 

Resources Board and qualifies as an ultra-low sulfur diesel fuel. It is a fuel derived

from vegetable oils or animal fats and meets the fuel specifications contained in the 

ASTM D6751 standard. Products that do not meet the ASTM D6751 standard are not 

biodiesel. Biodiesel may be blended in any proportion with standard petroleum-based 

diesel fuel. Biodiesel blends are usually referred to by the volume percentage of 

biodiesel in the blended product; e.g. B20 is a blend consisting of 20% biodiesel and 80% 

petroleum diesel by volume.

MSHA DPM compliance sampling has shown significant reductions in total carbon 

(TC) exposures at mines that use a high biodiesel content fuel blend. This result is 

consistent with previously published laboratory and in-mine data addressing 

particulate matter emission reductions when diesel engines are operated on these types 

of fuels. 

MSHA further analyzed this data to separately assess the elemental carbon (EC) and 

organic carbon (OC) emissions associated with biodiesel fuels. EC and OC combine to 

form TC, which is a major component of DPM and is regulated by MSHA in 

underground metal and nonmetal mines. MSHA found that, although the EC tended to 

be lowered significantly when biodiesel was used, some sampling data and research 

findings suggest that biodiesel could cause OC emissions to increase. MSHA became 

concerned that the reduction in EC emissions from use of biodiesel could be offset by a 

corresponding increase in OC emissions. Based on the available data, however, MSHA 

was unable to quantify the net effect of reduced EC emissions and increased OC 

emissions on TC exposures of miners.

Therefore, MSHA conducted a series of diesel emission tests to measure TC, EC, OC, 

and various exhaust gases resulting from the use of three different petroleum diesels, 

three different biodiesels, and a 50:50 blend of petroleum diesel and biodiesel. The 

three petroleum diesels tested included certified versions of low sulfur diesel (LSD) and 

ultra-low sulfur diesel (ULSD), representing the two fuel types currently used for 

engine approval testing by MSHA. Certified LSD is a diesel fuel meeting the 

specifications of 30 C.F.R. Part 7.86, Table E-1, with a total sulfur content of 0.03% to 

0.05%. Certified ULSD is a diesel fuel meeting the specifications of EPA Title 40, Part 

1065.703, Table 1, with a total sulfur content of 0.0007% to 0.0015%. A highway ULSD 

fuel was also tested as received from a local distributor, representing a typical fuel 

available commercially. The non-petroleum based fuels included two pure soy-based 

biodiesels and a blend of soy-based and animal fat-based biodiesels. MSHA also tested

a B50 blend of soy biodiesel and ULSD.
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MSHA conducted the testing at its Approval and Certification Center diesel laboratory 

using an Isuzu 4JG1T engine. Although MSHA’s testing was limited to this single 

engine model, the test results are expected to be qualitatively transferable to most other 

EPA Tier 2 or later off-road engine makes and models because of common design 

features affecting emissions, such as direct injection, high injection pressures, and 

turbocharging. For each fuel, MSHA tested the engine with and without a diesel 

oxidation catalyst (DOC, also known as an oxidation catalytic converter or OCC) 

installed in the engine’s exhaust. Engine performance and emissions were measured 

using the procedures and criteria established by MSHA under 30 C.F.R. Part 7, Subpart 

E (1996) addressing engine test procedures (based on ISO-8178 C-1, 8 mode test). 

MSHA also included gaseous emission measurements for carbon monoxide (CO), 

carbon dioxide (CO2), nitric oxide (NO) and nitrogen dioxide (NO2). MSHA analyzed 

the samples for TC (EC + OC) using NIOSH Analytical Method 5040 at its laboratory in 

Bruceton, Pennsylvania. 

The testing demonstrated that biodiesel produced a modest reduction in TC emissions 

when a DOC was not used. When a DOC was used, TC emissions from biodiesel were 

reduced significantly compared to petroleum diesel. Significant reductions in TC were 

observed using both B50 blend and 100% biodiesel. The highest TC reductions 

observed during the tests were achieved using 100% biodiesel in combination with a 

DOC. Analysis of the carbon components of DPM for the tests conducted showed 

several significant items that explain the resulting TC emissions:

• Biodiesel produced significant reductions in EC emissions.

• Biodiesel increased OC emissions compared to petroleum diesel when a DOC 

was not used. This increase partially offset the EC reduction, but not enough to 

cause a net TC increase.

• Use of a DOC did not have a net effect on EC emissions for any fuel.

• Use of a DOC produced a significant reduction in OC emissions for all fuels.

• The significant reduction in TC when using biodiesel with a DOC results from 

the EC reduction produced by biodiesel in combination with the DOC 

eliminating a significant portion of the OC emissions.

As is typical of most catalytic converters, the testing showed that for all fuels, the DOC 

nearly eliminated CO emissions and increased NO2 emissions. Adequate mine 

ventilation can control NO2 exposures to below the ceiling limit for NO2.

The study also documented the importance of engine duty cycle in influencing TC 

reduction from biodiesel fuel when a DOC was not used. Under a heavy duty cycle, the 

increase in OC due to the use of biodiesel was at a minimum. At lighter load 

conditions, the resulting OC emissions increased, both as a percentage of TC and as an 

absolute value. Since biodiesel is effective at reducing EC significantly at all load 

conditions, but produces the most OC increases at light loads, biodiesel is most effective 
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in reducing TC when the engine works hard. At both heavy and light engine load 

conditions, TC emissions were reduced when biodiesel was used together with a DOC, 

compared to petroleum-based diesel with or without a DOC. 

As noted above, this testing was limited to a single engine model. However, due to 

design features affecting emissions common with most other makes and models of Tier 

2 or later off-road engines, use of biodiesel fuel would be expected to produce 

qualitatively similar results with other engines. The exact percentage increases or 

decreases in emissions observed in this study using an Isuzu 4JG1T engine would not 

necessarily be expected with other engines, just as differences in fuel blend, duty cycle, 

or other sources of variability (see study report) would be expected to affect engine-out 

emissions. But similar upward and downward trends in the various emissions would 

be expected for most makes and models of Tier 2 or later off-road engines.

Bakground

MSHA’s DPM standard at 30 C.F.R. § 57.5060(b)(3) restricts an underground 

metal and nonmetal miner’s permissible exposure limit to 160 micrograms of 

total carbon per cubic meter of air (160TC μg/m3). In addition, 30 C.F.R. § 

57.5060(d) includes requirements for mine operators to install, use, and maintain 

all technologically and economically feasible controls to reduce a miner’s 

exposure to the DPM Permissable Exposure Limit (PEL). Mine operators have 

the flexibility to use engineering or administrative controls, or a combination of 

both, to reduce a miner’s exposure to or below the PEL. 

Since the 1960s, underground mine operators using diesel-powered equipment have 

employed DOCs, either installed by the original equipment manufacturer (OEM) or 

retrofitted at the mine to reduce concentrations of harmful gaseous emissions 

discharged into the mine environment, primarily CO and unburned hydrocarbons. 

While still used for this purpose, DOCs are now also used on diesel fleets in the 

underground and surface mining industries, as well as non-mining surface fleets to 

reduce the OC component of DPM. 

DOCs are readily available to the mining industry as OEM standard or optional 

equipment, or for retrofitting almost any piece of diesel-powered equipment. DOC

costs range from approximately $1,000 to $3,000. They are essentially maintenance free 

and last the life of an engine. Many equipment manufacturers routinely install a DOC 

as a standard exhaust system component on diesel equipment sold for underground 

use. Many diesel particulate filters (DPFs) also have a catalyzed coating similar to a

DOC, or a DOC can be installed upstream of a DPF in the exhaust system on a piece of 

diesel-powered equipment to reduce both gaseous and OC emissions.

In the 2001 DPM final rule (66 Fed. Reg. 5706), MSHA concluded that engineering 

controls, such as increased mine ventilation, low DPM emission engines, better diesel 
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engine maintenance, DOCs, DPFs, alternative fuels, and enclosed cabs with filtered 

breathing air were technologically and economically feasible. In the 2006 DPM rule, 

MSHA noted that the wider availability of alternative fuels, particularly biodiesel, 

improved DPF technology, and impending availability of the EPA compliant 2007 onroad diesel engines with integral DPFs would further reduce miners’ exposure to DPM.

Use of biodiesel fuel is becoming more common in underground metal and nonmetal 

mines because of its wider availability and its effectiveness in significantly reducing 

DPM and other harmful emissions. Underground metal and nonmetal mines are 

currently using biodiesel fuel in blends with standard petroleum diesel ranging from B5 

to B99, but blends with less than about 30 percent biodiesel do not appear to 

significantly reduce TC concentrations.

MSHA’s Technical Support is available to assist mine operators with questions 

concerning the application of biodiesel fuel blends and DOCs on underground mining 

equipment.

Authority

The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq.; 

and 30 C.F.R. §§ 57.5060(b)(3) and 57.5060(d).

Internet availability

This PIB may be viewed on the Internet by accessing the MSHA home page at 

(http://www.msha.gov) “Compliance Info” and “Program Information Bulletins.”

The Report titled “Diesel Fuel Testing on an Isuzu 4JG1T Engine With and Without a 

Diesel Oxidation Catalyst,” dated June 2009, is available on the Internet by accessing the 

MSHA home page at (http://www.msha.gov) “Diesel Particulate” “Metal/Nonmetal 

Mining Related.”

Issuing Office and Contact Persons

Technical Support, Approval and Certification Center

Russell Stackpole, (304) 547-2061

E-mail: stackpole.russell@dol.gov

Metal and Nonmetal Mine Safety and Health

Reginald J. Richards, DrPH, CIH, (202) 693-9600

E-mail: richards.reginald.j@dol.gov

Coal Mine Safety and Health, Safety Division

Michael G. Kalich, (202) 693-9714

E-mail: kalich.michael@dol.gov
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Distribution

Underground Metal and Nonmetal Miner’s Representatives

MSHA Program Policy Manual Holders

Underground Metal and Nonmetal Mine Operators

Manufacturers of Underground Diesel-Powered Mining Equipment

Metal and Nonmetal Special Interest Groups