53280 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

DEPARTMENT OF LABOR 

Mine Safety and Health Administration 

30 CFR Part 57 

RIN 1219–AB29 

Diesel Particulate Matter Exposure of 

Underground Metal and Nonmetal 

Mines 

AGENCY: Mine Safety and Health 

Administration (MSHA), Labor. 

ACTION: Proposed rule; notice of public 

hearings; close of comment period; 

request for data. 

SUMMARY: We propose to revise the 

January 20, 2006 effective date of the 

existing diesel particulate matter (DPM) 

final concentration limit of 160 

micrograms of total carbon (TC) per 

cubic meter of air (160TCμg/m3) in the 

2001 final rule ‘‘Diesel Particulate 

Matter Exposure of Underground Metal 

and Nonmetal Miners,’’ published in the 

Federal Register on January 19, 2001 

(66 FR 5706). We are considering 

staggered effective dates for 

implementation of the final DPM limit, 

phased-in over a multi-year period, 

primarily based on feasibility issues that 

have surfaced since promulgation of the 

2001 final rule. We also propose to 

delete the existing provision that 

restricts newer mines from applying for 

an extension of time for meeting the 

final concentration limit. In addition we 

are seeking specific comments and data 

on an appropriate conversion factor for 

the final DPM limit, technological 

implementation issues, and the costs 

and benefits of this rule. Finally, in this 

proposed rule, we are interested in 

comments on the appropriateness of 

including in a final rule a provision for 

medical evaluation of miners required 

to wear respiratory protection and 

transfer of miners who have been 

determined by a medical professional to 

be unable to wear a respirator. Specific 

questions regarding these issues are 

discussed within the appropriate 

sections in the preamble. These 

questions are italicized for ease of the 

reader. 

DATES: Public hearing dates and 

locations are discussed in the 

SUPPLEMENTARY INFORMATION section 

below. If you wish to make an oral 

presentation for the record, we ask that 

you submit your request at least 5 days 

prior to the hearing dates. Comments 

and other appropriate data for the 

record must be received by close of 

business on October 14, 2005. 

ADDRESSES: (1) To submit comments, 

please include RIN: 1219–AB29 in the 

subject line of the message and send 

them to us at either of the following 

addresses. 

Federal e-Rulemaking portal: Go to 

http://www.regulations.gov and follow 

the online instructions for submitting 

comments. 

E-mail: zzMSHA-comments@dol.gov. 

If you are unable to submit comments 

electronically, please identify them by 

RIN: 1219–AB29 and send them to us by 

any of the following methods. 

Fax: (202) 693–9441. 

Mail, hand delivery, or courier: 

MSHA, Office of Standards, 

Regulations, and Variances, 1100 

Wilson Blvd., Rm. 2350, Arlington, VA 

22209–3939. 

(2) We will post all comments on the 

Internet without change, including any 

personal information they may contain. 

You may access the rulemaking docket 

via the Internet at http://www.msha.gov/ 

regsinfo.htm or in person at MSHA’s 

public reading room at 1100 Wilson 

Blvd., Rm. 2349, Arlington, VA. 

(3) To receive an e-mail notification 

when we publish rulemaking 

documents in the Federal Register, 

subscribe to our list serve at http:// 

www.msha.gov/subscriptions/ 

subscribe.aspx. 

FOR FURTHER INFORMATION CONTACT: For 

information contact Rebecca J. Smith, 

Acting Director of the Office of 

Standards, Regulations, and Variances, 

MSHA, 1100 Wilson Blvd., Arlington, 

Virginia 22209–3939. Ms. Smith can be 

reached at (202) 693–9440. 

SUPPLEMENTARY INFORMATION: 

Outline of Preamble 

This outline will assist the mining 

community in finding information in 

this preamble. 

I. Public Hearings 

II. Rulemaking Background 

A. First Partial Settlement Agreement 

B. Second Partial Settlement Agreement 

III. Rulemaking History 

A. Advance Notice of Proposed 

Rulemaking (ANPRM) on the Interim 

and Final Concentration Limits 

B. Notice of Proposed Rulemaking (NPRM) 

on the Interim Limit 

C. Final Rule Revising the Interim 

Concentration Limit 

IV. Technological Feasibility 

A. Introduction 

B. Background 

C. Remaining Technological Feasibility 

Issues 

V. Complexity of Developing an Appropriate 

Conversion Factor for the Final 

Concentration Limit 

VI. Economic Feasibility 

VII. Section 101(a)(9) of the Mine Act 

VIII. Section-by-Section Analysis 

A. Section 57.5060(b) 

B. Effect of Eliminating § 57.5060(c)(3)(i) 

IX. Medical Evaluation and Transfer 

X. Regulatory Impact Analysis 

A. Executive Order 12866 

B. Costs 

C. Benefits 

XI. Regulatory Flexibility Act Certification 

XII. Paperwork Reduction Act 

XIII. Other Regulatory Considerations 

XIV. Proposed DPM Rule Text 

I. Public Hearings 

We will hold three public hearings on 

the proposed rule. The public hearings 

will be begin at 9 a.m., and will be held 

on the following dates and locations: 

Date Location Phone 

September 26, 2005 ................................ Little America Hotel, 500 South Main Street, Salt Lake City, UT 84101 ................ (801) 363–6781 

September 28, 2005 ................................ Clarion Hotel Sports Complex, 9103 E. 39th Street, Kansas City, MO 64133 ...... (816) 737–0200 

September 30, 2005 ................................ Marriott Louisville Downtown, 280 West Jefferson Street, Louisville, KY 40202 ... (800) 228–9290 

If you wish to make an oral 

presentation for the record, we ask that 

you submit your request at least 5 days 

prior to the hearing dates. However, you 

do not have to make a written request 

to speak. Any unallotted time will be 

made available for persons making 

same-day requests. 

The hearings will begin with an 

opening statement from MSHA, 

followed by an opportunity for members 

of the public to make oral presentations 

to a panel. Speakers will speak in the 

order that they sign in. At the discretion 

of the presiding official, the time 

allocated to speakers for their 

presentation may be limited. Speakers 

and other attendees may also present 

information to the MSHA panel for 

inclusion in the rulemaking record. 

The hearings will be conducted in an 

informal manner. The hearing panel 

may ask questions of speakers. Although 

formal rules of evidence and cross 

examination will not apply, the 

presiding official may exercise 

discretion to ensure the orderly progress 

of the hearing and may exclude 

irrelevant or unduly repetitious material 

and questions. 

Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 53281 

A verbatim transcript of the 

proceedings will be included in the 

rulemaking record. Copies of this 

transcript will be available to the public, 

and can be viewed at http:// 

www.msha.gov. 

We will accept post-hearing written 

comments and other appropriate data 

for the record from any interested party, 

including those not presenting oral 

statements, through close of business on 

October 14, 2005. 

II. Rulemaking Background 

On January 19, 2001 we published a 

final rule addressing the health hazards 

to underground metal and nonmetal 

miners from exposure to diesel 

particulate matter (DPM) (66 FR 5706). 

The rule established new health 

standards for these miners by requiring, 

among other things, use of engineering 

and work practice controls to reduce 

DPM to prescribed limits. It set an 

interim and final DPM concentration 

limit in the underground metal and 

nonmetal mining environment with 

staggered effective dates for 

implementation of the concentration 

limits. The interim concentration limit 

of 400TC μg/m3 was to become effective 

on July 20, 2002. The final 

concentration limit of 160TC μg/m3 is 

scheduled to become effective January 

20, 2006. In the 2001 final rule, we 

projected that the mining industry 

would meet the final concentration limit 

in their mines through the use of diesel 

particulate filtration devices, ventilation 

changes, and the turnover of equipment 

and engines to less polluting models (66 

FR 5713, 5888). 

Several mining trade associations and 

individual mine operators challenged 

the final rule and the United 

Steelworkers of America (USWA) 

intervened in the case, which is now 

pending in the United States Court of 

Appeals for the District of Columbia 

Circuit. The parties agreed to resolve 

their differences through settlement 

negotiations with us and we delayed the 

effective date of certain provisions of 

the standard. 

A. First Partial Settlement Agreement 

On July 5, 2001, as a result of an 

agreement reached in settlement 

negotiations, we published two notices 

in the Federal Register. One notice (66 

FR 35518) delayed the effective date of 

§ 57.5066(b) related to tagging 

requirements in the maintenance 

standard. The second notice (66 FR 

35521) proposed a rule to make limited 

revisions to § 57.5066(b) and added a 

new paragraph to § 57.5067(b) 

‘‘Engines’’ regarding the definition of 

the term ‘‘introduced.’’ We published 

the final rule on February 27, 2002 (67 

FR 9180). 

B. Second Partial Settlement Agreement 

Settlement negotiations continued on 

the remaining unresolved issues in the 

litigation, and on July 15, 2002, the 

parties finalized a written agreement (67 

FR 47296, 47297). Under the agreement, 

the interim concentration limit of 

400TC μg/m3 became effective on July 

20, 2002, without further legal 

challenge. We afforded mine operators 

one year to develop and implement 

good-faith compliance strategies to meet 

the interim concentration limit, and we 

agreed to provide compliance assistance 

during this one-year period. We also 

agreed to propose rulemaking on several 

other disputed provisions of the 2001 

final rule. The legal challenge to the rule 

was stayed pending completion of the 

additional rulemakings. 

On July 20, 2003, we began full 

enforcement of the interim 

concentration limit of 400TC μg/m3. Our 

enforcement policy was also based on 

the terms of the second partial 

settlement agreement and includes the 

use of elemental carbon (EC) as an 

analyte to ensure that a citation based 

on the 400 TC concentration limit is 

valid and not the result of interferences 

(67 FR 47298). The policy was 

discussed with the DPM litigants and 

stakeholders on July 17, 2003. 

III. Rulemaking History 

A. Advance Notice of Proposed 

Rulemaking (ANPRM) on the Interim 

and Final Concentration Limits 

On September 25, 2002, we published 

an Advance Notice of Proposed 

Rulemaking (ANPRM) (67 FR 60199). 

We noted in the ANPRM that the scope 

of the rulemaking was limited to the 

terms of the Second Partial Settlement 

Agreement and posed a series of 

questions to the mining community 

related to the 2001 final rule. We also 

stated our intent to propose a rule to 

revise the surrogate for the interim and 

final concentration limits and to 

propose a DPM control scheme similar 

to that included in our longstanding 

hierarchy of controls scheme used in 

our air quality standards (30 CFR 56/ 

57.5001–.5006) for metal and nonmetal 

mines. In addition, we stated that we 

would consider technological and 

economic feasibility for the 

underground metal and nonmetal 

mining industry to comply with revised 

interim and final DPM limits. We 

determined at that time that some mine 

operators had begun to implement 

control technology on their 

underground diesel-powered 

equipment. Therefore, we requested 

relevant information on current 

experiences with availability of control 

technology, installation of control 

technology, effectiveness of control 

technology to reduce DPM levels, and 

cost implications of compliance with 

the 2001 final rule. 

B. Notice of Proposed Rulemaking 

(NPRM) on the Interim Limit 

In response to our publication of the 

ANPRM, some commenters 

recommended that we propose separate 

rulemakings for revising the interim and 

final concentration limits to give us an 

opportunity to gather further 

information to establish a final DPM 

limit, particularly regarding feasibility. 

In the subsequent notice of proposed 

rulemaking (NPRM) published on 

August 14, 2003 (68 FR 48668), we 

concurred with these commenters and 

notified the public in the NPRM that we 

would propose a separate rulemaking to 

amend the existing final concentration 

limit of 160TC μg/m3. We also requested 

comments on an appropriate final DPM 

limit and solicited additional 

information on feasibility. The proposed 

rule also addressed the interim 

concentration limit by proposing a 

comparable PEL of 308 μg/m3 based on 

the EC surrogate and included a number 

of other provisions. 

C. Final Rule Revising the Interim 

Concentration Limit 

We published the final rule revising 

the interim concentration limit on June 

6, 2005 (70 FR 32868). This rule 

changed the interim concentration limit 

of 400 μg/m3 measured by TC to a 

comparable PEL of 308 μg/m3 measured 

by EC. The rule requires our 

longstanding hierarchy of controls that 

is used for our other exposure-based 

health standards at metal and nonmetal 

mines, but retains the prohibition on 

rotation of miners for compliance. 

Furthermore, the rule, among other 

things, requires us to consider economic 

as well as technological feasibility in 

determining if operators qualify for an 

extension of time in which to meet the 

final DPM limit, and deletes the 

requirement for a control plan. 

Currently, the following provisions of 

the DPM standard are effective: 

§ 57.5060(a), establishing the interim 

PEL of 308 micrograms of EC per cubic 

meter of air which is comparable in 

effect to 400 micrograms of TC per cubic 

meter of air; § 57.5060(d), Addressing 

control requirements; § 57.5060(e), 

Prohibiting rotation of miners for 

compliance with the DPM standard; 

§ 57.5061, Compliance determinations; 

§ 57.5065, Fueling practices; § 57.5066, 

53282 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

Maintenance standards; § 57.5067, 

Engines; § 57.5070, Miner training; 

§ 57.5071, Exposure monitoring; and, 

§ 57.5075, Diesel particulate records. 

IV. Technological Feasibility 

A. Introduction 

When we promulgated the 2001 final 

rule, we determined that control 

technologies would be available by 

January 20, 2006 to reduce DPM 

concentrations to 160TC μg/m3

micrograms in all types of underground 

metal and nonmetal mines. In the 2001 

final rule, we established a new 

compliance scheme for these mine 

operators to implement that was 

distinguishable from that of our other 

exposure-based health standards by 

requiring that miners’ exposures be 

reduced to a full-shift equivalent 

environmental or concentration limit 

where miners work or travel. 

Historically, our metal and nonmetal 

exposure-based health standards have 

been based on a miner’s full-shift 

personal exposure and required that 

mine operators reduce miners’

exposures to hazardous chemical 

substances by establishing a hierarchy 

of controls utilizing feasible engineering 

and administrative controls 

supplemented by respiratory protection, 

if necessary. Since, we were regulating 

DPM for the first time we needed a tool 

to help us to determine whether the 

mining industry was capable of meeting 

the interim and final concentration 

limits of the 2001 final rule using a 

combination of engineering and work 

practice controls. We also needed a 

compliance assistance tool to help mine 

operators with selection of feasible 

controls from technology unfamiliar to 

the mining industry. Consequently, we 

developed the Estimator. 

The Estimator mathematically 

calculates the effect of any combination 

of engineering and ventilation controls 

on existing DPM concentrations in a 

given production area of a mine. This 

model is in the form of a spreadsheet 

template that permits instant display of 

outcomes as inputs are altered. 

Depending on the amount and type of 

equipment an operator uses, mining 

companies could use the Estimator to 

evaluate the effectiveness of these 

controls prior to purchasing and 

installing such controls. We encouraged 

mine operators to use this tool to assist 

them in making their decisions 

regarding the appropriate controls for 

their mines in meeting the 2001 

concentration limits. 

In the preamble to the 2001 final rule, 

we included data from our studies 

where we evaluated emissions 

generated by diesel powered equipment 

in several diverse underground mining 

operations which included an 

underground limestone mine, an 

underground salt mine, and an 

underground gold mine. In each mine, 

we concluded that the necessary 

combination of controls was available to 

reduce DPM concentrations well below 

the final concentration limit. Based on 

these studies, we concluded that 

engineering and work practice controls 

were available to reduce DPM 

concentrations in all underground metal 

and nonmetal mines to the required 

limits. We also distributed to the mining 

community our publication of ‘‘Practical 

Ways to Control Exposure to Diesel 

Exhaust in Mining—a Toolbox’’ which 

addresses various categories of available 

DPM controls. These categories of 

controls include use of low emission 

engines, low sulfur fuel, aftertreatment 

devices, ventilation, enclosed cabs, 

engine maintenance, work practices and 

training, fleet management, and 

respiratory protective equipment (66 FR 

5712–13). Furthermore, we also 

examined information regarding types 

of engines and equipment found in 

underground metal and nonmetal mines 

along with their various ventilation 

systems and concluded that the 2001 

final rule was technologically feasible 

for the mining industry (66 FR 5889). 

We also concluded that the 2001 final 

rule was economically feasible but 

recognized the broad impact of the rule 

on the underground metal and nonmetal 

sector of the mining industry. We 

estimated that the annual cost of the 

2001 final rule for these mines would be 

$25.1 million. The cost for an average 

underground metal and nonmetal mine 

was projected to be approximately 

$128,000 annually primarily for 

investment in equipment to meet the 

interim and final concentration limits. 

In reaching our cost estimates, we 

anticipated that the interim 

concentration limit would be met 

primarily with the use of diesel 

particulate filters (DPFs), environmental 

cabs, and ventilation; and the final 

concentration limit would be met with 

expanded use of DPFs, ventilation, and 

turnover in equipment to less polluting 

models (66 FR 5713, 5888). 

We included a provision in the 2001 

final rule to allow an additional two 

years for mines experiencing difficulty 

in reducing DPM levels to the final 

concentration limit due to technological 

constraints (66 FR 5861). The June 6, 

2005, final rule on the interim limit 

subsequently revised the extension 

requirement to provide one year, 

renewable, extensions to comply with 

the final limit, based on economic or 

technological infeasibility, but 

continues to prohibit newer mines from 

applying for extensions (70 FR 32966). 

Following promulgation of the 2001 

final rule, we agreed to engage in a joint 

MSHA/industry 31-Mine Study to, 

among other things, assess the 

technological and economic feasibility 

of underground metal and nonmetal 

mine operators to achieve compliance 

with the interim and final DPM 

concentration limits. Feasibility at each 

of the 31 mines was determined using 

the Estimator. The analyses were based 

on the highest DPM sample result 

obtained at each mine and all major 

DPM emission sources at each mine 

plus spare equipment. On January 6, 

2003, we issued our final report 

entitled, ‘‘MSHA’S Report on Data 

Collected during a Joint MSHA/Industry 

Study of DPM Levels in Underground 

Metal and Nonmetal Mines.’’ With 

regard to feasibility of compliance with 

both the interim and final concentration 

limits, we concluded in the study that 

it may be both technologically and 

economically feasible for metal and 

nonmetal underground mines to comply 

with the 2001 rule. At that time, 

however, we acknowledged our limited 

in-mine documentation on 

implementation of DPM control 

technology with issues such as 

retrofitting and regeneration of filters. 

Consequently, we committed to 

continue to consult with the National 

Institute for Occupational Safety and 

Health, industry and labor 

representatives on the availability of 

practical mine worthy filter technology. 

NIOSH peer reviewed our final report of 

the 31-Mine Study (70 FR 32870–73). 

Furthermore, by letter to MSHA dated 

June 25, 2003, NIOSH stated that: 

Operators will need to make informed 

decisions regarding filter selection, 

retrofitting, engine and equipment 

deployment, operation, and maintenance, 

and specifically work through issues such as 

in-use efficiencies, secondary emissions, 

engine backpressure, DPF regeneration, DPF 

reliability and durability. NIOSH is of the 

opinion that these issues can be solved if the 

informed decisions mentioned above are 

made. (70 FR 32923) 

In the 2005 rulemaking on the interim 

limit, we revised our approach to 

reducing DPM levels by establishing our 

longstanding hierarchy of controls used 

for regulating our other exposure-based 

health standards at metal and nonmetal 

mines. Also, we changed the 

concentration limit to a permissible 

exposure limit whereby we measure a 

miner’s personal exposure. The 

Estimator became less significant from 

our perspective in demonstrating 

feasibility since the 2005 rulemaking 

Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 53283 

record included more extensive 

evidence on the ability of the mining 

industry to meet the interim limit in 

2005. Specifically, our rulemaking 

record included: our final report on the 

31-Mine Study; NIOSH’s peer review of 

the 31-Mine Study; results from our 

baseline sampling at mines covered 

under the DPM standard; results of our 

comprehensive compliance assistance 

work at mining operations with 

implementation issues affecting 

feasibility; NIOSH’s conclusions on the 

performance of the SKC sampler and the 

availability of technology for control of 

DPM; NIOSH’s Diesel Emissions 

Workshops in 2003 in Cincinnati and 

Salt Lake City; the Filter Selection 

Guide posted on the MSHA and NIOSH 

web sites; MSHA’s final report on DPM 

filter efficiency; NIOSH’s report titled, 

‘‘Review of Technology Available to the 

Underground Mining Industry for 

Control of Diesel Emissions’; and, the 

NIOSH Phase I Isozone study titled, 

‘‘The Effectiveness of Selected 

Technologies in Controlling Diesel 

Emissions in an Underground Mine—

Isolated Zone Study at Stillwater 

Mining Company’s Nye Mine,’’ all of 

which were developed following 

promulgation of the 2001 DPM final rule 

(70 FR 32916). 

To attain the interim DPM limit, mine 

operators are required to install, use, 

and maintain engineering and 

administrative controls to the extent 

feasible. When these controls do not 

reduce a miner’s exposure to the DPM 

limit, controls are infeasible, or controls 

do not produce significant reductions in 

DPM exposures, operators must 

continue to use all feasible engineering 

and administrative controls and 

supplement them with respiratory 

protection. When respiratory protection 

is required under the final standard, 

mine operators must establish a 

respiratory protection program that 

meets the specified requirements. At 

this time, we believe that this 

compliance approach coupled with the 

time-frame for complying with the 

phased-in limits provides mine 

operators with maximum flexibility in 

compliance. We believe that this current 

compliance approach which 

incorporates the industrial hygiene 

concept of a hierarchy of controls 

scheme for implementing DPM controls 

would result in feasibility of compliance 

with each of the phased-in limits 

contained in this proposal. However, we 

continue to acknowledge that 

compliance difficulties may be 

encountered at some mines due to 

implementation issues and the cost of 

purchasing and installing certain types 

of controls. 

1. MSHA’s 2001 Assumptions Regarding 

Compliance With the Final 

Concentration Limit 

The assumptions that we used in 2001 

in support of our cost estimates 

included: 

(a) Fifty percent of the fleet will have new 

engines (these new engines do not impact 

cost of the rule) * * * Moreover, due to EPA 

[Environmental Protection Agency] 

regulations which will limit DPM emissions 

from engines used in surface construction, 

surface mining, and over-the-road trucks (the 

major markets for heavy duty diesel engines), 

the market for low tech ‘‘dirtier’’ engines will 

dry up * * * (b) one hundred percent of the 

production equipment and about fifty 

percent of the support equipment will be 

equipped with filters; (c) about thirty percent 

of all equipment will need to be equipped 

with environmentally controlled cabs; (d) 

twenty three percent of the mines would 

need new ventilation systems (fans and 

motors); (e) forty percent of the mines will 

need new motors on these fans; and (f) thirty 

two percent of the mines will need major 

ventilation upgrades (66 FR 5889–90). 

Furthermore, we concluded that it 

would not be feasible to require this 

sector, as a whole, to lower DPM 

concentrations further, or to implement 

the required controls more swiftly (66 

FR 5888). 

2. Reasons Why the 2001 Assumptions 

Are Now Being Questioned. 

During the 41⁄2 years since the 2001 

final rule was promulgated, the mining 

industry and MSHA have gained 

considerable experience with the 

implementation, use, and cost of DPM 

control technology. Miners’ DPM 

exposures have also have declined 

significantly from a mean of 

808DPM μg/m3 (646TC μg/m3 μg/m3

equivalent) prior to the implementation 

of the standard, to a mean of 233TC μg/ 

m3 based on current enforcement 

sampling. The industry, however, is 

encountering economic and 

technological feasibility issues with 

DPM controls as they strive to reduce 

levels below the interim limit. When we 

established the 2001 final limit, we were 

expecting some mine operators to 

encounter difficulties implementing 

control technology because the rule was 

technology forcing. We projected that by 

this time, practical and effective filter 

technology would be available that 

could be retrofitted onto most 

underground diesel powered 

equipment. However, as a result of our 

compliance assistance efforts and 

through our enforcement of the interim 

limit, we have become aware that this 

assumption may not be valid. The 

applications, engineering and related 

technological implementation issues 

that we believed would have been easily 

solved by now are more complex and 

extensive than previously thought. 

Although DPF systems have been 

proven to be highly effective in reducing 

elemental carbon, mines are currently 

experiencing problems with selection 

and implementation of DPF systems for 

complying with the interim limit. Since 

the final limit will require mines to 

install more DPF systems, these 

selection and implementation problems 

will extend over a large portion of the 

mining industry. At this time we believe 

that solutions to the problems of 

selection and implementation have not 

proceeded as quickly as anticipated 

since promulgation of the 2001 final 

rule and many mines will not be able to 

achieve the final limit by January 20, 

2006. Some of the implementation and 

operational difficulties encountered 

with the controls are discussed in the 

sections below. 

We seek additional information 

regarding technological difficulties and 

whether they will increase the cost to 

comply with the final concentration 

limit above that estimated in the 2001 

final rule. We are particularly interested 

in whether mine operators have 

attempted to institute DPF systems that 

are impractical or have failed to work 

for their mining operations. We wish to 

know what types and sizes of DPFs have 

been evaluated, what types of 

equipment have been fitted with DPFs, 

what types and horsepower of engines 

were installed on the equipment, details 

concerning monitoring of equipment 

exhaust temperatures prior to specifying 

a DPF for a given application, whether 

DPF installations include a provision for 

backpressure monitoring, DPF 

maintenance intervals, DPF life, the 

results of any DPF failure mode 

analysis, DPM reductions obtained, and 

any other data related to in-mine 

experiences with DPFs on underground 

metal and nonmetal mining equipment. 

We believe that wider use of 

alternative fuels and filter technology 

can make the 160TC μg/m3 final limit 

feasible if a staggered phase-in approach 

is adopted. By lowering the exposure 

limit in intervals over five years 

beginning in January 2007, market 

forces should have sufficient time and 

incentive to adjust to the new standard. 

Specifically, a reliable alternative fuel 

distribution system should induce mine 

operators to adopt this relatively lowcost method to achieve compliance. The 

development and distribution of 

alternative fuels is also encouraged by 

existing tax credits. We believe that 

regional distribution networks are 

53284 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

beginning to emerge. We seek data on 

alternative fuel distribution systems. 

Retrofit options for self-cleaning 

filters should increase as the filter 

manufacturers become assured of a 

reliable market for the devices. Use of 

newer equipment with cleaner engines 

will also increase as older equipment is 

retired from service. We anticipate that 

this staggered approach will provide the 

needed time to resolve these logistical 

and operational issues, and 

consequently, may not increase our 

2001 projection of the cost of 

compliance with the rule. During this 

phase-in, we will continue to work with 

the Diesel Partnership (discussed below) 

and the mining industry to address the 

DPF selection and implementation 

problems and identify effective 

solutions for the diverse metal and 

nonmetal mining environment. 

Additionally, we request comments on 

the percentage of diesel equipment, by 

mine size, in metal and nonmetal mines 

that currently have newer, low DPM 

emitting engines such as EPA Tier I and 

Tier 2 compliant engines. Our 2001 cost 

estimates were based, in part, on the 

assumption that by the effective date of 

the final limit, 50% of the diesel 

equipment fleet would have new 

engines (66 FR 5889). We are interested 

in whether our 2001 assumption was 

accurate. If the percentage is lower than 

originally estimated, it may require the 

industry to rely even more heavily on 

filters and other types of controls at 

added costs. Relying on DPFs to be 

installed on older, higher DPM emitting 

engines may also introduce additional 

implementation issues since DPF 

manufacturers normally do not 

recommend adding DPFs to older 

engines. Although we recognize various 

types of controls that mine operators 

could use to reduce miner exposure to 

DPM, we believe that turnover in 

equipment to less polluting models and 

the use of DPFs would be the primary 

method of achieving compliance with 

the final DPM limit. 

We also recognize promising 

advances in alternative fuel technology 

since the 2001 final rule was 

promulgated. These fuels can be 

extremely effective in reducing DPM 

emissions. Additionally, the fuels 

would be in tune with recent U.S. 

initiatives towards greater energy 

independence. On October 22, 2004, 

President Bush signed into law a 50- 

cent-per-gallon tax credit for producers 

of bio-diesel. He also extended federal 

tax credits for ethanol through 2007 as 

part of H.R. 4520, also known as the 

American Jobs Creation Act of 2004 

(Pub. L. 108–357). 

Currently, however, logistical 

problems exist with the distribution of 

these fuels to remote mining areas, and 

the effect of these fuels on power output 

and operation at high altitude needs to 

be addressed more fully. 

Although MSHA, industry, and the 

Diesel Partnership are actively working 

to address these concerns, additional 

time may be needed to find effective 

solutions for the implementation of 

DPM controls. 

B. Background 

1. Diversity of Underground Mines 

Affected By the Final DPM 

Concentration Limit 

The metal and nonmetal mining 

industry has 177 underground mines 

that use numerous pieces of diesel 

powered equipment, widely distributed 

throughout each mining operation. 

These mines employ an array of mining 

technologies to produce commodities 

including metals such as lead, zinc, 

platinum, gold, silver, etc. Also, there 

are different types of nonmetal mines 

that produce stone products such as 

limestone, dolomite, sandstone, and 

marble. Other underground nonmetal 

mines produce clay, potash, trona, soda 

ash, and salt. Not only do these mines 

vary in the commodities that they 

produce, but they also use different 

mine designs and mining techniques 

such as room and pillar mining and 

stope mining. Some of these mines are 

large, complex multilevel mines, while 

others are small adit-type mines. 

Ventilation levels in these mines also 

vary widely. Many limestone mines 

have only natural ventilation with 

variable air movement, whereas trona 

mines have high ventilation rates to 

dilute and remove methane gas released 

in the mining process. There are also 

deep metal mines with multiple levels 

that have far less ventilation than that 

found in underground trona mines. 

Furthermore, many metal and nonmetal 

mines are located in remote areas of the 

country, at high altitudes, or are subject 

to extremely hot or cold environments. 

Considering these factors as a whole, we 

have found that there is no single 

solution to control technology that 

would be effective for all metal and 

nonmetal mines in significantly 

reducing current DPM levels to or below 

the final DPM concentration limit of 

160TC micrograms. 

2. Work of the M/NM Diesel Partnership 

(the Partnership) 

Since promulgation of the January 

2001 final rule, we have worked with a 

Partnership that is composed of 

representatives from the National 

Institute for Occupational Safety and 

Health (NIOSH), industry trade 

associations, and organized labor. We 

are not a member of the Partnership 

because of our ongoing DPM rulemaking 

activities. The primary purpose of the 

Partnership is to identify 

technologically and economically 

feasible controls using existing and 

available technology that can be 

retrofitted onto existing diesel powered 

equipment in underground metal and 

nonmetal mines to reduce diesel 

particulate matter emissions to, or 

below, our interim and final limits. 

The Partnership has been actively 

involved with NIOSH in its work on 

diesel particulate control technology 

including its isolated zone studies at the 

Stillwater Mine in Montana. NIOSH has 

published the following reports of its 

work with the Partnership: ‘‘The 

Effectiveness of Selected Technologies 

in Controlling Diesel Emissions in an 

Underground Mine—Isolated Zone 

Study at Stillwater Mining Company’s 

Nye Mine (Phase I Study);’’ ‘‘An 

Evaluation of the Effects of Diesel 

Particulate Filter Systems on Air 

Quality and Personal Exposure of 

Miners at Stillwater Mining Case Study: 

Production Zone (Phase II Study);’’ and, 

‘‘The Effectiveness of Reformulated 

Fuels and Aftertreatment Technologies 

in Controlling Diesel Emissions (Phase 

III—A Study in an Isolated Zone at 

Stillwater Mining Company’s Nye Mine 

August 31–September 11, 2004).’’

NIOSH stated in its conclusion to the 

Phase III study that: 

This study did not address the important 

critical path of economic and technical 

aspects relating to implementation of the 

studied technologies into underground 

mines. The successful implementation of 

control technologies is predicated on 

addressing issues which are relatively unique 

to each mine and even to individual 

applications within a given mine. Most of 

these technical and operational issues could 

be investigated through a series of long-term 

field studies where control technologies 

would be wisely selected and optimized for 

the applications, performance of the 

technologies would be continuously 

monitored and the effects of the controls on 

concentrations of diesel pollutants in the 

mine air would be periodically assessed. The 

findings of such studies would allow 

operators to make informed decisions 

regarding the selection, optimization and 

implementation of control technologies for 

its applications and maximize the benefits of 

using those technologies. It is recommended 

that these studies be designed and 

undertaken under the leadership of the 

Metal/Nonmetal Diesel Partnership. 

On-going NIOSH diesel research 

related to the Partnership includes a 

contract that the NIOSH Pittsburgh 

Research Laboratory issued to Johnson 

Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 53285 

Matthey Catalyst to develop a system to 

control nitrogen dioxide (NO2) 

emissions from diesel-powered 

underground mining vehicles equipped 

with the Johnson Matthey’s 

Continuously Regenerating Trap (CRT) 

system. This system promotes 

regeneration at lower temperatures and 

is widely used in urban bus 

applications. If the results of laboratory 

evaluations show that a system is 

suitable for use in underground mining, 

NIOSH would continue studying this 

control technology with a long-term 

field evaluation in an underground 

mine. 

C. Remaining Technological Feasibility 

Issues 

In January 2001, we concluded that 

technology existed to sample accurately 

for DPM with a TC method and to bring 

DPM levels to the 160 TC level by 

January 2006 (66 FR at 5889). We 

further concluded that if any particular 

mine found unforeseen technological 

barriers to meeting the January 2006 

deadline, it could apply for an extension 

of up to two additional years to comply 

with the 160 limit (66 FR at 5889). Our 

discussion of technological feasibility in 

support of the interim PEL of 308EC μg/ 

m3 in the June 6, 2005 final rule 

concluded that it was technologically 

feasible to reduce underground miners’

exposures to the interim PEL by using 

available engineering control technology 

and various administrative control 

methods. In fact, our testing at 

Kennecott Minerals Green’s Creek Mine 

showed that ceramic diesel particulate 

filters (DPFs) were capable of reducing 

diesel exposures by 95%. However, we 

acknowledged that compliance 

difficulties may be encountered at some 

mines due to implementation issues and 

the cost of purchasing and installing 

certain types of controls. Specifically, 

implementation issues may adversely 

affect the feasibility of using DPFs to 

reduce exposures despite the results 

reported in NIOSH’s Phase I Isozone 

Study. 

Our experience since January 2001 

has raised questions on technological 

feasibility for the mining industry as a 

whole, rather than for a small number 

of individual mines, to meet the 160 TC 

concentration limit by January 20, 2006. 

When we conducted our baseline 

sampling in 2002 and 2003, we found 

that over 75% of the underground mines 

covered by the 2001 final rule have 

levels that would exceed the final 

concentration limit of 160TC

micrograms. Our current enforcement 

data indicate that approximately 65% of 

the underground mines covered by the 

2001 final rule have levels that would 

exceed the final concentration limit. 

Although exposures have decreased 

with implementation of controls and 

enforcement of the interim 

concentration limit, we have tentatively 

concluded that the 160TC microgram 

final concentration limit presents a 

significant challenge to a substantial 

number of underground mine operators 

and compliance may not be feasible by 

January 2006. That conclusion is 

supported by our current enforcement 

sampling results that indicate that many 

mining operations have exposures above 

the 160TC concentration limit, and 

availability of effective control 

technology that will reduce exposures to 

the final limit is speculative at this time. 

Moreover, comments from industry 

trade associations and individual mine 

operators in the post-January 2001 

rulemakings recommended that we 

repeal the 160 limit as technologically 

infeasible. Organized labor, on the other 

hand, has recommended that a limit 

below 160 is technologically feasible. 

We request comments on whether 

compliance is technologically feasible 

by January 2006 and the 

appropriateness of a multi-year phasein of the final limit. We also request 

comments and data on when the 

technology will be feasible. Specific 

technological implementation issues are 

discussed in more detail in the 

following subsections C.1 through C.4. 

We also request comments on whether 

compliance difficulties may lead to 

another problem by requiring a large 

number of miners to wear respirators 

until feasible controls are fully 

implemented. We have never had a 

standard that resulted in a significant 

percentage of the workforce being 

required to wear respiratory protection, 

and we are concerned about the impact 

on worker acceptance of the rule and 

about mine operators’ ability to remain 

productive. We are interested in public 

comment on how many miners would 

need to wear respirators to comply with 

the 2001 final limit and proposed multiyear phase-in of the final limit, and 

whether in each case they would need 

to wear respirators for their entire work 

shift, whether this amount of respirator 

usage is practical, and any other 

comments or observations concerning 

this issue. 

1. Implementation of Available DPFs 

We continue to project that many 

mine operators will have to use DPFs to 

reduce DPM levels to the final 

concentration limit. The mining 

industry maintains that while some 

operators are using DPFs to control 

miners’ exposures to the interim PEL, it 

is infeasible for them to further reduce 

miners’ exposures through expanded 

use of DPFs. 

While passive DPF regeneration 

systems are preferred over active 

regeneration systems, many pieces of 

mining equipment do not have duty 

cycles that will consistently support 

passive regeneration. Passive 

regeneration is the process where the 

exhaust gas temperature produced by 

the engine is sufficient to burn off the 

collected DPM on the DPF. Passive 

regeneration is normally preferred 

because a DPF can be installed on a 

machine, and the operator does not have 

to be concerned with removing the DPF 

on a routine schedule that may occur at 

the end of every shift. However, passive 

regeneration does require the machine 

operator to monitor the engine’s exhaust 

gas backpressure. As the DPF loads up 

with DPM, the inability of the exhaust 

gas to burn off the DPM allows the 

backpressure to increase. Increasing the 

backpressure above the manufacturer’s 

specifications can cause engine and DPF 

damage. We request information on the 

number of currently installed passive 

regeneration DPF filters. Also, we are 

interested in the methods used by the 

industry to match a passive 

regeneration DPF to a machine. 

However, we are aware that two 

identical machines operating in two 

different mines may not both be able to 

use passive regeneration. We would be 

interested in comments about practical 

experience with these implementation 

issues. 

If passive regeneration is infeasible, 

active regeneration is an alternative. 

Active regeneration depends on an 

external heat source for burning off the 

DPM. Mine operators have informed us 

that some mining operations cannot 

utilize active regeneration due to 

physical size of filters, machine down 

time, or the cost associated with 

underground regeneration stations 

required for DPF regeneration. We 

request that commenters submit 

information from the mines that are 

utilizing active regeneration including 

data regarding the benefits and the 

practicability of active regenerating 

filters. 

Engine emissions and exhaust flows 

also affect the size of the DPF that needs 

to be installed. Both of these factors can 

affect both passive and active 

regeneration. If the DPF is undersized 

for a particular application due to high 

DPM emissions or high exhaust flows, a 

passive or active DPF system may not 

make it through the entire shift before 

it must be taken out of service for 

regeneration because of the high 

backpressure. 

53286 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

While some of the mining industry 

has made improvements by replacing 

older engines with newer engines in 

order to reduce DPM emissions, we 

believe this has occurred mostly for the 

larger horsepower engines, greater than 

150 hp. Smaller engines normally found 

in the support equipment have not had 

DPM reductions equivalent to the larger 

engines. Since we estimated that 50% of 

the support equipment would probably 

need DPFs for compliance with the final 

limit (66 FR 5889–90), the higher DPM 

emissions from the engines used in 

support equipment can further 

complicate the impact on compliance. 

The mining industry has stated that it 

needs additional time to further 

evaluate the proper sizing of DPF 

systems for both passive and active 

regeneration. 

We seek further comment regarding 

these technological implementation 

issues as they affect feasibility of 

compliance with the final concentration 

limit including the practicality of 

available DPM control technology. We 

request that the mining community 

specifically address issues surrounding 

off-board regeneration: back pressure 

build up; frequency of the necessity to 

clean DPFs; the difficulty of placement 

of regeneration stations; and 

information on the extent to which 

diesel powered equipment 

accommodates a retrofit of the DPF. 

2. Benefits of On-Board Regeneration 

a. ArvinMeritor System. The 

ArvinMeritor system, which utilizes 

active regeneration of the DPF, offers 

great potential for underground mines 

in further reducing DPM exposures. The 

ArvinMeritor system utilizes an onboard fuel burner system to regenerate 

DPFs. This system actively regenerates 

the filter media during normal 

equipment operations by causing the 

fuel to ignite the burner and thereby 

increase the exhaust temperature in the 

filter system. Consequently, this system 

does not require the host vehicle to 

travel to a regeneration station to 

regenerate the DPF. The condition of the 

DPF is monitored via sensors. While 

this product was successfully evaluated 

at Stillwater’s Nye Mine, we have 

recently learned that the manufacturer 

has decided to concentrate on working 

with Original Equipment Manufacturers 

(OEMs) where they would be selling 50 

units or more to one customer rather 

than selling one or two units per 

customer. 

b. Johnson Matthey’s CRT System for 

DPM reduction (Johnson Matthey). As 

stated above, passive regeneration works 

by using the exhaust gas generated by 

the engine to burn the DPM. Normally, 

DPF manufacturers utilize catalyst 

technology to lower the temperature 

needed for successful passive 

regeneration. By lowering the exhaust 

gas temperature needed for passive 

regeneration, a broader range of 

machines will have the necessary duty 

cycle to generate the exhaust gas 

temperature needed to burn the DPM. 

However, when a platinum coating is 

used as the catalyst, it can also increase 

the nitrogen dioxide (NO2) emissions 

from the engine exhaust. In mines with 

low ventilation rates, the increased NO2

emissions can also result in increased 

NO2 exposures to potentially dangerous 

levels for miners. We discuss this issue 

in the final rule on the interim PEL (70 

FR 32924–26). Therefore, other methods 

for passive regeneration are being 

developed to resolve these issues. 

In 2004, the NIOSH Pittsburgh 

Research Laboratory issued a contract to 

Johnson Matthey to develop a system 

that can regenerate at lower exhaust gas 

temperatures and control NO2

emissions. The system is based on 

Johnson Matthey’s CRT system and 

promotes regeneration at lower 

temperatures. Such DPFs are widely 

used in urban bus applications and are 

capable of passively regenerating DPFs 

at the temperatures commonly seen in 

the exhausts of underground mining 

equipment (above 250 °C for at least 

40% of the operation time). 

The laboratory evaluation of the 

systems is being executed under NIOSH 

contract by the Center for Diesel 

Research (CDR) at the University of 

Minnesota. The objective is to examine 

performance and suitability of the 

systems relative to heavy-duty diesel 

engines in underground mining 

applications, with specific focus on the 

effectiveness of controlling NO2. If the 

results of laboratory evaluations show 

that the system is suitable for use in 

underground applications, NIOSH 

would continue to study this promising 

control with a long-term field evaluation 

in an underground mine environment. 

We request comments from the mining 

community regarding the foreseeable 

utility of these and other new control 

technologies for reducing DPM levels in 

underground metal and nonmetal 

mines. 

3. Operators’ Limited Access to 

Alternative Fuels and Ultra LowSulphur Fuels 

During our compliance assistance 

efforts, we observed mines with several 

applications of alternative fuels, 

including water emulsion fuels and biodiesel fuels both of which are EPA 

approved fuels. We subsequently tested 

these alternative fuels to determine if 

they could decrease tailpipe DPM 

emissions. In each application the 

change to an alternative fuel had a 

positive impact on reducing engine 

emissions and miners’ exposures to 

DPM. In some cases, reductions of 50 to 

80+ percent were measured. While we 

found notable benefits, the use of 

alternative fuels can also cause 

equipment operation issues for mine 

operators. These operational issues have 

included initial clogging of the fuel 

filters when bio-diesel is used, 

reduction of horsepower with the use of 

water emulsion fuels, and management 

of proper fueling of the correct fuel into 

specific machines. While these 

operational issues could be overcome, 

each mine has to work through 

implementation issues on a case-by-case 

basis. 

The most common problem with 

alternative fuels is lack of geographic 

proximity of most mines to a fuel 

distributor. Fuel distribution centers 

tend to be near large cities. As a result, 

alternative fuels need to be transported 

to mine sites, in some cases significantly 

increasing costs. Fuel manufacturers are 

building distribution centers near 

mining areas to reduce the 

transportation costs, but these centers 

will take some additional time to 

complete. Limited distribution is also a 

feasibility issue for metal and nonmetal 

mine operators who seek to obtain ultra 

low sulfur fuel. However, as discussed 

elsewhere in this preamble, the 

commercial availability of ultra low 

sulfur fuel will increase during 2006 

and beyond when on-highway vehicles 

in the United States will be required by 

the EPA to use only this type of diesel 

fuel. 

a. Water Emulsion Fuels. Water 

emulsion fuels, such as PuriNox, are 

blends of diesel fuels and water. The 

water is held in suspension with a 

surfactant. The water in the fuel reduces 

the engine combustion temperature 

resulting in reduced NO2 and reduced 

DPM emissions. However, the added 

water also reduces the engine’s 

horsepower. While the per gallon price 

of the water emulsion fuel is the same 

as standard fuel, we are aware of 

increases in engine consumption of 

these fuels by as much as 15 percent. 

However, continued increased use in 

mines is currently limited due to lack of 

fuel availability in most mining regions. 

Manufacturers of this fuel must install 

centralized blender facilities in order to 

make the fuel more available and 

economically feasible for use by the 

metal and nonmetal mining industry. 

Some fuel system issues have also 

been observed with some engines using 

water emulsion fuels. One issue appears 

Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 53287 

to be with the use of very efficient water 

separators used on engine fuel systems 

to remove water from the fuel lines. A 

very efficient water separator will 

actually remove the water from the 

emulsion, thus affecting the engine’s 

performance. An engine manufacturer 

that has experienced this with its 

engines has recommended replacing the 

more efficient water separator with a 

less efficient one. 

Another issue identified by some 

mine operators is that some small 

machines cannot run, or run poorly, on 

this fuel. We are not aware of any 

testing that has been done to prove or 

disprove this. This may or may not be 

due to less complex fuel systems that 

cannot handle a change in fuel 

properties. We request any information 

that would help a mine operator 

determine if certain machines in a fleet 

cannot run efficiently on this type of 

fuel. 

Since water emulsion fuels have been 

associated with horsepower loss, mines 

will have to determine through their 

own in-mine test if their machines can 

continue to operate efficiently even with 

the power loss. Some situations where 

the power loss could affect a machine’s 

productivity occur at multilevel 

underground mines at high altitudes. 

Also, mines that require the use of 

permissible engines with pre-chamber 

combustion, such as the metal and 

nonmetal gassy mines, may need to 

determine any additional effects on 

these types of engines. These mines may 

need additional time to assess the 

impact of the elevation and grade on 

power loss. We request comments on 

the mining industry’s experience with 

using water emulsion fuels to reduce 

DPM exposures. 

b. Bio-Diesel Fuels. While bio-diesel 

fuels are more readily available than 

water emulsion fuels, there has not been 

a consistent supply or standard cost of 

the fuel. Both costs and demand for 

these fuels in the mining industry have 

been related primarily to tax credits 

available for using the fuel. With current 

tax credits, bio-diesel can be an 

attractive fuel alternative for the mining 

industry. However, we have observed 

maintenance issues with application of 

bio-diesel fuels similar to those 

associated with water emulsion fuels. 

Particularly, bio-diesel functions as a 

solvent and cleans the fuel system. This 

results in increased clogging and 

replacement of fuel filters. It may take 

the mining industry some additional 

time to assess the impact of the 

increased maintenance on a mining 

operation. 

The other issue related to the use of 

bio-diesel fuel is the percent of soy oil 

in the mixture. While any blend is 

available, B20 is a 20 percent blend, and 

B50 is a 50 percent blend, etc., we note 

that significant DPM reductions are not 

realized unless the bio-diesel blend 

exceeds 20 percent. We request 

comments on the mining industry’s 

experience with using bio-diesel fuels to 

reduce DPM exposures. 

4. Installation of Environmental Cabs 

Environmental cabs are a proven 

means to reduce worker exposure to 

DPM. While much of the constructiontype equipment used in underground 

stone mines comes equipped with 

environmental cabs, the cabs on 

specialty mining equipment used in 

underground hard rock mining are less 

common, particularly in mines with 

narrow drifts or low seam heights. As 

mine operators realize the benefits of 

cabs, more and more pieces of 

equipment are being purchased or 

retrofitted with environmental cabs. 

These cabs provide protection for 

workers not only from diesel particulate 

but also from noise and dust. 

Many mines have begun a retrofit 

program, but may require additional 

time to design and retrofit specialty 

mining equipment with environmental 

cabs. We request comments on the 

mining industry’s experience with using 

environmental cabs to reduce DPM 

exposures. 

V. Complexity of Developing an 

Appropriate Conversion Factor for the 

Final Concentration Limit 

The June 6, 2005 rule uses a 1.3 

conversion factor to convert the interim 

PEL of 400TC μg/m3 to 308EC μg/m3, 

because EC comprises only a fraction of 

TC. We used a factor of 1.3, to be 

divided into 400TC μg/m3, to produce a 

reasonable estimate of TC without 

interferences. The EC interim limit is 

based on the median TC to EC (TC/EC) 

ratio of 1.3 that was observed for valid 

samples in the 31-Mine Study and 

agreed to in the second partial DPM 

settlement agreement (70 FR 32944). 

Enforcement sample results to date have 

also shown that for the 400TC μg/m3

interim limit, 1.3 is the most 

appropriate conversion factor. 

However, we believe at this time that 

the 1.3 conversion factor may not be 

appropriate to convert the final phasedin TC limits to EC because of the variety 

of DPM controls being adopted by mine 

operators since the 31-Mine Study. 

Depending on the types of DPM controls 

being installed at the mines, a new 

conversion factor for EC may be needed. 

Clean engines have more of an impact 

on reducing OC levels. Alternative fuels, 

ventilation, and work practices seem to 

lower EC and TC at similar rates, while 

DPF and environmental cabs appear to 

be more effective in reducing EC levels. 

The actual TC to EC ratio could vary 

from mine to mine, and even from one 

section in a mine to another, based on 

the mix of controls at a mine. We are 

seeking to maintain the level of 

protection for miners provided by the 

final limit promulgated by the 2001 

final rule, pursuant to Section 101(a)(9) 

of the Mine Act. When considering the 

feasibility of compliance and sampling 

constraints, we believe that the 

conversion factor from TC to EC for the 

phased-in final limits should take into 

account the OC and EC ratios so that the 

OC and EC components together would 

be equivalent to a TC concentration. We 

are working with NIOSH to develop an 

appropriate conversion factor for 

converting the TC limits of this 

rulemaking to EC limits. Information 

provided by NIOSH indicated that the 

ratio of TC to EC in the 31-Mine Study 

is 1.25 to 1.67 (70 FR 32944). NIOSH’s 

report on the Phase I study conducted 

in May, 2003, shows that the EC 

reduction in the isolated zone with one 

DPF system was 88% and that two other 

systems gave greater than 96% EC 

reductions when the measured 

concentrations were normalized by 

ventilation rate. In the final report of the 

Phase II study, NIOSH indicated that 

higher EC reductions were observed in 

the field than were obtained in the 

laboratory for whole diesel particulate. 

The results of these studies, as well as 

other mine studies NIOSH has 

conducted, help inform us of the EC to 

TC ratio at different DPM 

concentrations. Measuring only the EC 

component ensures that only diesel 

particulate material is being measured. 

However, there are no established 

relationships between the concentration 

of EC and total DPM under various 

operating conditions. We welcome 

comments regarding the types of data 

we should request from NIOSH to assist 

us in developing an appropriate 

conversion factor for converting the TC 

limits of this proposed rule to EC limits. 

We will initiate a separate rulemaking 

to determine what the correct TC to EC 

conversion factor will be for the phasedin final limits. In the meantime, we are 

interested in receiving comments on 

whether the record supports an EC PEL 

without regard to any conversion factor, 

the appropriate conversion factor if one 

is used, and any other scientific 

approaches for converting the existing 

TC limit to an appropriate EC limit. 

However, if a rulemaking to establish a 

conversion factor is not complete before 

January 20, 2007, we are considering 

53288 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

using the current 1.3 conversion factor 

that we used to establish the interim 

DPM PEL of 308 EC micrograms to 

convert the phased-in final DPM TC 

limits to EC equivalents. As we did with 

the interim TC limit pursuant to the July 

2002 settlement, we would use the EC 

equivalents as a check to validate that 

an overexposure is not the result of 

interferences. We are interested in 

receiving comments on this approach to 

enforcement of the 2007 PEL, assuming 

the conversion factor rulemaking is not 

completed before January 20, 2007. 

VI. Economic Feasibility 

In January 2001, we estimated that 

yearly cost of the final rule would be 

about 0.67% of yearly industry revenue, 

which was less than the 1% ‘‘screen’’ of 

costs relative to revenues that we use as 

a presumptive benchmark of economic 

feasibility (66 FR 5889). In this 

rulemaking to consider a phased-in 

approach to the final concentration limit 

of 160 TC micrograms, we intend to use 

the entire rulemaking record supporting 

the 2001 final rule and the new 

information gathered during the recent 

rulemaking to promulgate the new 

interim PEL. Our data in the rulemaking 

record established that few underground 

mines would experience severe 

economic hardship from enforcement of 

the interim PEL. Our subsequent 

enforcement data have confirmed that 

the interim PEL is economically 

feasible. In order to gain a more 

thorough rulemaking record, 

particularly in light of recent 

technological developments, we request 

comments on the economic feasibility of 

the final concentration limit of 160 TC 

micrograms and implications of the 

proposed phase-in approach on the 

economic feasibility. 

VII. Section 101(a)(9) of the Mine Act 

Section 101(a)(9) of the Mine Act 

provides that: ‘‘No mandatory health or 

safety standard promulgated under this 

title shall reduce the protection afforded 

miners by an existing mandatory health 

or safety standard.’’ We interpret this 

provision of the Mine Act to require that 

all of the health or safety benefits 

resulting from a new standard be at least 

equivalent to all of the health or safety 

benefits resulting from the existing 

standard when the two sets of benefits 

are evaluated as a whole. The U.S. Court 

of Appeals for the D.C. Circuit approved 

such a ‘‘net effects’’ application of 

Section 101(a)(9). Int’l Union, UMWA v. 

Federal Mine Safety and Health Admin., 

407 F. 3d 1250, 1256–57 (DC Cir. 2005). 

We have tentatively concluded at this 

point that this proposed phase-in period 

of the effective date of existing 

§ 57.5060(b) of the 2001 final rule 

establishing a final DPM concentration 

limit of 160TC μg/m3 will not reduce 

miner protection. We are concerned that 

the final concentration limit may be 

infeasible for the mining industry in 

January 2006. Feasibility issues with 

respect to operator compliance are 

discussed above. Also, an additional 

concern is whether an effective 

sampling strategy exists to enforce the 

final TC concentration limits with TC as 

the surrogate. Evidence in the 

rulemaking record after January 2001 

suggests that, in many cases, there is no 

practical sampling strategy that would 

adequately remove organic carbon 

interferences that occur when TC is 

used as the surrogate. Furthermore, the 

DPM settlement agreement does not 

address appropriate enforcement 

procedures for the final concentration 

limit. We also believe at this time that 

the 1.3 conversion factor used for the 

final interim limit may not be 

appropriate for substantially lower 

limits, such as the final TC 

concentration limit of 160TC μg/m3. 

Thus, we have concluded at this time 

that it is questionable whether the final 

concentration limit of 160TC μg/m3

would provide any more protection for 

miners than the 308EC μg/m3 interim 

limit. We have the burden of proof to 

confirm that an overexposure to DPM 

actually occurred and the sample result 

is not due to interferences. If we were 

to enforce the final DPM concentration 

limit of 160TC μg/m3, we would need to 

validate a TC sample result, which 

cannot be done without an appropriate 

conversion factor for EC. 

We request comments on whether a 

five-year phase-in period for lowering 

the final concentration limit to 160TC

μg/m3 complies with Section 101(a)(9) 

of the Mine Act. 

VIII. Section-by-Section Discussion of 

the Proposed Rule 

A. Section 57.5060(b) 

Section 57.5060(b) in the 2001 rule 

established a final concentration limit of 

160TC μg/m3 to become effective after 

January 19, 2006. In this rulemaking, we 

propose to stagger the effective dates for 

implementation of the final DPM limit, 

phased-in over a five year period. In a 

separate rulemaking, we will propose 

changing the phased-in limits from TC 

to EC. As previously discussed in 

Section IV, Technological Feasibility, 

issues have surfaced since promulgation 

of the 2001 final rule that indicate the 

mining industry, taken as a whole, may 

need additional time to address 

implementation issues. We are still 

committed to ensuring that mine 

operators continue the significant 

progress they have already 

demonstrated in reducing miners’

exposures to DPM. As a first step in 

revising the final concentration limit, 

we are proposing the interim PEL of 308 

micrograms to remain in effect until 

January 20, 2007, based on feasibility 

concerns with respect to compliance 

and sampling strategy discussed above. 

MSHA is interested in whether the 

mining community believes at this time 

that a reduction, after that date, of the 

PEL equivalent by 50TC μg/m3 each year 

from 400TC μg/m3, is feasible and will 

provide additional time for the 

implementation of controls and 

development of distribution systems for 

alternative fuels. We also request 

information and comments on mining 

industry current experiences with 

feasibility of compliance with a limit 

lower than the current interim PEL of 

308 μg/m3 of elemental carbon (EC). 

The proposed rule would establish 

the existing interim PEL of 308TC μg/m3

as the new final PEL for one year until 

January 20, 2007, and impose limits that 

are reduced by what we will determine 

in a separate rulemaking to be the 

equivalent of 50 micrograms of total 

carbon from 400TC μg/m3 each 

succeeding year until the final PEL of 

160TC μg/m3 is reached in 2011. 

Consistent with the 2005 final rule on 

the interim limit, we propose to change 

the final limit from a concentration limit 

to a PEL. We request comments on 

whether five years is the correct 

timeframe for reducing miners’

exposures to the 160 micrograms of TC 

as originally established in the 2001 

standard and to have been effective in 

January 2006. Also, we request 

information on whether the proposed 

annual 50 microgram reductions of the 

final DPM limit are appropriate or, in 

the alternative, should the final rule 

include an approach such as one or two 

reductions. 

We intend that the provisions 

regarding extensions of time in which to 

meet the final concentration limit 

pursuant to existing § 57.5060(c) would 

apply to the limits established in 

proposed § 57.5060(b) effective January 

20, 2006. If a mine requires additional 

time to come into compliance with the 

revised limit of 308 EC for the first year 

as in proposed § 57.5060(b)(1) or with 

the final DPM limit established in any 

other paragraph of proposed 

§ 57.5060(b) due to technological or 

economic constraints, the operator of 

the mine could file an application with 

our District Manager for a special 

extension. We request your comments 

on the impact of granting extensions for 

Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 53289 

compliance with exposure limits that 

are greater than the 160 TC final limit. 

We intend to cite a violation of the 

DPM exposure limit only when we have 

solid evidence that a violation actually 

occurred. Accordingly, we would 

continue to determine that an 

overexposure has occurred when a 

sample exceeds the interim limit using 

an appropriate error factor. The 

appropriate error factor would be 

slightly different for each of the reduced 

PELs. Our error factor model accounts 

for both intra- and inter-laboratory 

analytical variability and combines that 

variability with variability in pump flow 

rate and other sampling and analytic 

variables. The appropriate error factors 

will be based on the same statistically 

sound paired-punch database as used 

for the existing exposure limit. When 

developed, they will be further 

discussed on our Web site at http:// 

www.msha.gov under, ‘‘Single Source 

Page for Metal and Nonmetal Diesel 

Particulate Matter Regulations.’’

B. Effect of Eliminating § 57.5060(c)(3)(i) 

The 2001 final rule included a 

requirement at § 57.5060(c)(3)(i) 

specifying that applications for a oneyear special extension in which to 

comply with the final DPM 

concentration limit of 160 micrograms 

of TC include information adequate for 

the Secretary to ascertain that dieselpowered equipment was used in the 

subject mine prior to October 29, 1998. 

In our 2005 rule addressing the interim 

limit, we revised the extension 

provisions, but we retained the October 

29, 1998 factor for our District Manager 

to consider in granting extensions. The 

basis for limiting special extensions to 

underground mines that operated 

diesel-powered equipment prior to 

October 29, 1998 was that we released 

our NPRM of our 2001 final rule on that 

date. We reasoned that some mines in 

operation prior to that date could 

experience compliance difficulties 

relating to such factors as the basic mine 

design, use of older equipment with 

high DPM emissions, etc., and that as a 

result, some of these mines may require 

additional time to attain compliance 

with the final DPM limit. Also, we 

envisioned that mines opened after that 

date would be using cleaner engines 

that would greatly benefit them in 

complying with the 2001 final 

concentration limit. Now, we believe 

that our assumptions were incorrect. 

We now believe that it is unnecessary 

to limit the application of extensions to 

mines operating diesel equipment prior 

to October 29, 1998, because under 

current § 57.5060(c), it is voluntary as to 

whether a mine operator applies for a 

special extension. Extensions involve 

paperwork which result in a document 

that a mine operator can rely on for one 

year (renewable) to show our inspectors 

that we have determined that it is 

technologically or economically 

infeasible at this time for that particular 

mine operator to achieve compliance 

with the final limit using engineering 

and administrative controls. If their 

miners are wearing respirators, they are 

in compliance and no citation is issued. 

This is exactly the same test and the 

same result under § 57.5060(d) at mines 

without a formal extension. Under the 

current rule, mine operators must use 

all feasible engineering and 

administrative controls to achieve 

compliance. If we determine that 

reaching the final limit is infeasible for 

technological or economic reasons, and 

over-exposed miners are in respirators, 

the operator is deemed to be in 

compliance and no citation is issued. 

We will periodically check to determine 

current DPM exposures and the ability 

of the mine operator to implement new 

control technology. 

We request comments on the benefits 

of current § 57.5060(c)(3)(i), and the 

effects of deleting the requirement, 

along with the number of miners that 

would be affected if § 57.5060(c)(3)(i) 

were eliminated. We also request 

comments on whether the elimination 

of § 57.5060(c)(3)(i) would result in a 

reduction in the current level of health 

protection afforded to miners. 

IX. Medical Evaluation and Transfer 

We believe that the phase-in approach 

of this proposed rule for ultimately 

reducing miners’ exposures to 160 

micrograms of total carbon will resolve 

many of the existing feasibility issues 

related to effectively implementing 

more engineering and administrative 

controls in metal and nonmetal 

underground mines to enhance miners’

health. Consequently, fewer miners 

would be required to wear a respirator 

to supplement feasible engineering and 

administrative controls. Whereas most 

mines can feasibly comply with the 

existing DPM interim PEL of 308 

micrograms of elemental carbon, we 

expect that some miners will continue 

to have to wear respirators. With each 

lower limit, more miners may have to 

wear respirators for longer time periods 

until controls become feasible. In the 

event that miners cannot wear a 

respirator, existing § 57.5060(d) allows 

for the use of an air purifying respirator, 

such as those that are integrated into a 

hardhat. We believe that such 

respirators are an effective option under 

the interim PEL for persons who cannot 

wear a negative-pressure respirator. 

We are interested in comments from 

the mining community on whether we 

should include in the final rule, 

pursuant to Section 101(a)(7) of the 

Mine Act, a provision requiring a 

medical evaluation to determine a 

miner’s ability to use a respirator before 

the miner is fit tested or required to 

work in an area of the mine where 

respiratory protection must be used 

under the final limits. In addition, we 

are seeking comments on whether the 

final rule should contain a requirement 

for transfer of a miner to an area of the 

mine where respiratory protection is not 

required if a medical professional has 

determined in the medical evaluation 

that the miner is unable to wear a 

respirator for medical reasons. 

Currently, our standards do not 

require medical transfer of metal and 

nonmetal miners. We are interested in 

whether the public believes that we 

should amend the existing respiratory 

protection requirement at § 57.5060(d) 

by adding new paragraphs (d)(3) and 

(d)(4) that would address medical 

evaluation and transfer rights for 

miners. We particularly want to know if 

the final rule should include the 

following language: 

(3) The mine operator must provide a 

medical evaluation, at no cost to the miner, 

to determine the miner’s ability to use a 

respirator before the miner is fit tested or 

required to use the respirator to work at the 

mine. 

(4) Upon notification from the medical 

professional that a miner’s medical 

examination shows evidence that the miner 

is unable to wear a respirator, the miner must 

be transferred to work in an existing position 

in an area of the same mine where respiratory 

protection is not required. 

(i) The miner must continue to receive 

compensation at no less than the regular rate 

of pay in the classification held by that miner 

immediately prior to the transfer. 

(ii) The miner must receive wage increases 

based upon the new work classification. 

We also solicit comments from the 

public as to whether a transfer provision 

in the final rule should address issues 

of notification to the District Manager of 

the health professional’s evaluation and 

the fact that a miner will be transferred; 

the appropriate timeframe within which 

the transfer must be made; whether a 

record of the medical evaluation 

conducted for each miner should be 

maintained along with the correct 

retention period; medical 

confidentiality; and any other relevant 

issues such as costs to mine operators 

for implementing a rule requiring 

medical evaluations and transfer of 

miners. 

We preliminarily estimate that 

medical evaluation and transfer 

requirements, as described above in 

53290 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

1The following section, discussing benefits of the 

proposed rule, notes that MSHA’s original estimate, 

in 2001, of the benefits of the final limit assumed 

that mean miner exposure to DPM was larger than 

that observed in subsequent sampling of baseline 

and current DPM concentrations experienced by 

underground M/NM miners. To the extent that 

benefits were accordingly overestimated in 2001, 

we expect that the 2001 estimates of cost impacts 

may have been inflated similarly. 

proposed § 57.5060(d)(3) and (3)(4), 

would affect about 50 miners annually 

for evaluation, about 3 miners annually 

for transfer, and cost about $40,000 

annually. 

X. Regulatory Impact Analysis 

A. Executive Order 12866 

Executive Order 12866 requires 

regulatory agencies to assess both the 

costs and benefits of regulations. In 

making this assessment, we determined 

that this final rule will not have an 

annual effect of $100 million or more on 

the economy, and therefore is not an 

economically significant regulatory 

action as defined by § 3(f)(1) of E.O. 

12866. 

B. Costs 

In Chapter IV of the Regulatory 

Economic Analysis in support of the 

January 19, 2001 final rule (2001 REA), 

we estimated total yearly costs to 

underground M/NM mines for the DPM 

final rule of $25,149,179 (p. 106). Of this 

amount, $6,612,464 was the discounted 

incremental yearly cost of compliance 

with the final limit. The undiscounted 

incremental yearly cost for compliance 

with the final limit was estimated as 

$9,274,325 (p. 58).1

This proposed rule would amend the 

January 19, 2001 final DPM rule by 

phasing in the 160TC μg/m3 final limit 

over a five-year period to address 

technological feasibility constraints that 

have arisen. The discounted present 

value of the cost saving from this fiveyear phase-in period would be 

$25,512,045, if compliance with the 

160TC μg/m3 final limit were 

technologically feasible in 2006. The 

annualized value of this cost saving, 

using a discount rate of 7%, would be 

$1,785,843. Table X–1 shows these 

calculations and also shows the 

breakdown of these cost savings by 

mine size. 

During the 41⁄2 years since the 2001 

final rule was promulgated, the mining 

industry and MSHA have gained 

considerable experience with the 

implementation, use, and cost of DPM 

control technology, which could result 

in cost changes. Therefore, we solicit 

public comment concerning the cost of 

compliance, including any changes in 

costs that may have occurred since the 

2001 REA. 

C. Benefits 

In Chapter III of the Regulatory 

Economic Analysis in support of the 

January 19, 2001 final rule (2001 REA), 

we demonstrated that the DPM final 

rule for M/NM mines will reduce a 

significant health risk to underground 

miners. This risk included the potential 

for illnesses and premature death, as 

well as the attendant costs of the risk to 

the miners’ families, to the miners’

employers, and to society at large. 

We have incorporated into this 

rulemaking record the previous DPM 

rulemaking records, including the risk 

assessment to the January 19, 2001 

standard. Benefits of the January 19, 

2001 final rule include continued 

reductions in lung cancers. In the long 

run, as the mining population turns 

over, we estimated that a minimum of 

8.5 lung cancer deaths will be avoided 

per year. We noted that this estimate 

was a lower bound figure that could 

significantly underestimate the 

magnitude of the health benefits. For 

example, the estimate based on the 

mean value of all the quantitative 

estimates examined in the January 19, 

2001 final rule was 49 lung cancer 

deaths avoided per year. 


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Other benefits noted in the 2001 REA 

were reductions in the risk of premature 

death from cardiovascular, 

cardiopulmonary, or respiratory causes 

and reductions in the risk of sensory 

irritation and respiratory symptoms. 

However, we did not include these 

health benefits in its estimates because 

we could not make reliable or precise 

quantitative estimates of them. 

Nevertheless, we noted that the 

expected reductions in the risk of death 

from cardiovascular, cardiopulmonary, 

or respiratory causes and the expected 

reductions in the risk of sensory 

irritation and respiratory symptoms are 

likely to be substantial. You are 

encouraged to submit additional 

evidence of new scientific data related 

to the health risk to underground metal 

and nonmetal miners from exposure to 

DPM. 

The 2001 risk assessment used the 

best available data on DPM exposures at 

underground M/NM mines to quantify 

excess lung cancer risk. ‘‘Excess risk’’

refers to the lifetime probability of dying 

from lung cancer during or after a 45- 

year occupational DPM exposure. This 

probability is expressed as the expected 

excess number of lung cancer deaths per 

thousand miners occupationally 

exposed to DPM at a specified mean 

DPM concentration. The excess is 

calculated relative to baseline, agespecific lung cancer mortality rates 

taken from standard mortality tables. In 

order to properly estimate this excess, it 

is necessary to calculate, at each year of 

life after occupational exposure begins, 

the expected number of persons 

surviving to that age with and without 

DPM exposure at the specified level. At 

each age, standard actuarial adjustments 

must be made in the number of 

survivors to account for the risk of dying 

from causes other than lung cancer. 

Occupational exposure is assumed to 

begin at age 20 and to continue, for 

surviving miners, until retirement at age 

65. The accumulation of lifetime excess 

risk continues after retirement through 

the age of 85 years. 

Table X–2, taken from the 2001 risk 

assessment, shows a range of excess 

lung cancer estimates at mean exposures 

equal to the interim and final DPM 

limits. The eight exposure-response 

models employed were based on studies 

by Sa ̈verin et al. (1999), Johnston et al. 

(1997), and Steenland et al. (1998). 

Assuming that TC is 80 percent of 

whole DPM, and that the mean ratio of 

TC to EC is 1.3, the interim DPM limit 

of 500 μg/m3 shown in Table X–2 

corresponds to the 308 μg/m3 EC 

surrogate limit adopted under the June 

6, 2005 rulemaking. 

TABLE X–2.—EXCESS LUNG CANCER RISK EXPECTED AT SPECIFIED DPM EXPOSURE LEVELS OVER AN OCCUPATIONAL

LIFETIME (EXTRACTED FROM TABLE III–7 OF THE 2001 RISK ASSESSMENT). 

Study and statistical model 

Excess lung cancer deaths per 

1000 occupationally exposed 

workers †

Final DPM 

limit 200 μg/ 

m3

Interim DPM 

limit 500 μg/ 

m3

Sa ̈verin et al. (1999) 

Poisson, full cohort ........................................................................................................................................... 15 44 

Cox, full cohort ................................................................................................................................................. 70 280 

Poisson, subcohort ........................................................................................................................................... 93 391 

Cox, subcohort ................................................................................................................................................. 182 677 

Steenland et al. (1998) 

5-year lag, log of cumulative exposure ............................................................................................................ 67 89 

5-year lag, simple cumulative exposure ........................................................................................................... 159 620 

Johnston et al. (1997) 

15-year lag, mine-adjusted ............................................................................................................................... 313 724 

15-year lag, mine-unadjusted ........................................................................................................................... 513 783 

†Assumes 45-year occupational exposure at 1920 hours per year from age 20 to retirement at age 65. Lifetime risk of lung cancer adjusted for 

competing risk of death from other causes and calculated through age 85. Baseline lung cancer and overall mortality rates from NCHS (1996). 

As explained in the June 6, 2005 final 

rule, the mean DPM concentration 

levels estimated from both the 31-Mine 

Study (432–492 μg/m3, depending on 

whether trona mines are included) and 

the baseline samples (≈320 μg/m3) fall 

between the interim and final DPM 

limits shown in Table X–2. All of the 

exposure-response models shown are 

monotonic (i.e., increased exposure 

yields increased excess risk, though not 

proportionately so). Therefore, using the 

most current available estimates of 

mean exposure levels, they all predict 

excess lung cancer risks somewhere 

between those shown for the interim 

and final limits. Thus, despite 

substantial improvements apparently 

attained since the 1989–1999 sampling 

period addressed by the 2001 risk 

assessment, underground M/NM miners 

are still faced with an unacceptable risk 

of lung cancer due to their occupational 

DPM exposures. 

Another principal conclusion of the 

2001 risk assessment was: 

By reducing DPM concentrations in 

underground mines, the rule will 

substantially reduce the risks of material 

impairment faced by underground miners 

exposed to DPM at current levels. 

Although DPM levels have apparently 

declined since 1889–1999, MSHA 

expects that further improvements will 

continue to significantly and 

substantially reduce the health risks 

identified for miners. There is clear 

evidence of DPM’s adverse health 

effects, not only at pre-2001 levels but 

also at the generally lower levels 

currently observed at many 

underground mines. These effects are 

material health impairments as 

specified under § 101(a)(6)(A) of the 

Mine Act. From the recent enforcement 

sample results, 135 out of the 183 mines 

(73.8%) had at least one sample 

exceeding the final exposure limit. 

Because the exposure-response 

relationships shown in Table X–2 are 

monotonic, MSHA expects that 

industry-wide implementation of the 

interim limit will significantly reduce 

the risk of lung cancer among miners. 

This proposed rule would amend the 

January 19, 2001 final DPM rule by 

phasing in the final limit over a fiveyear period to address technological 

feasibility constraints that have arisen. 

By addressing the technological 

feasibility issues in this way, this 

proposed rule would contribute to the 

53292 Federal Register / Vol. 70, No. 172 / Wednesday, September 7, 2005 / Proposed Rules 

realization of the benefits mentioned 

above. 

XI. Regulatory Flexibility Act 

Certification 

The Regulatory Flexibility Act (RFA) 

requires regulatory agencies to consider 

a rule’s economic impact on small 

entities. Under the RFA, we must use 

the Small Business Act definition of a 

small business concern in determining a 

rule’s economic impact unless, after 

consultation with the SBA Office of 

Advocacy, and after opportunity for 

public comment, we establish a 

definition which is appropriate to our 

activities and publish that definition in 

the Federal Register. For the mining 

industry, SBA defines ‘‘small’’ as having 

500 or fewer workers. We have 

traditionally considered small mines to 

be those with fewer than 20 workers. 

To ensure that the rule conforms to 

the RFA, we analyzed the economic 

impact on mines with 500 or fewer 

workers and also on mines with fewer 

than 20 workers. In Chapter V of the 

2001 REA we estimated yearly revenues 

for these mine sizes. In Table X–1 of this 

preamble, we estimate the cost savings 

to mines of various employment sizes. 

In Table XI–1 of this preamble we 

combine these numbers and calculate 

cost savings as a percentage of revenues. 

Cost savings are 0.25% of revenues for 

mines with fewer than 20 employees 

and 0.06% of revenues for mines with 

500 or fewer employees. Since both cost 

savings calculations are less than one 

percent of revenues, there is no need to 

conduct an initial regulatory flexibility 

analysis. We solicit public comment 

concerning the accuracy of these cost 

estimates. 

We certify that the rule will not have 

a significant economic impact on a 

substantial number of small entities 

under either definition. 

XII. Paperwork Reduction Act 

There are no paperwork provisions in 

this proposed rule. 

XIII. Other Regulatory Considerations 

A. National Environmental Policy Act of 

1969 

We have reviewed this proposed rule 

in accordance with the requirements of 

the National Environmental Policy Act 

(NEPA) of 1969 (42 U.S.C. 4321 et seq.), 

the regulations of the Council on 

Environmental Quality (40 U.S.C. part 

1500), and the Department of Labor’s 

NEPA procedures (29 CFR part 11). 

This proposed rule would have no 

significant impact on air, water, or soil 

quality; plant or animal life; the use of 

land; or other aspects of the human 

environment. As a result of this 

environmental assessment, we find that 

the proposed rule would have no 

significant impact on the human 

environment. Accordingly, we have not 

provided an environmental impact 

statement. We solicit public comment 

concerning the accuracy and 

completeness of this environmental 

assessment. 

B. The Unfunded Mandates Reform Act 

of 1995 

This proposed rule does not include 

any Federal mandate that may result in 

increased expenditures by State, local, 

or tribal governments, nor would it 

increase private sector expenditures by 

more than $100 million annually, nor 

would it significantly or uniquely affect 

small governments. Accordingly, the 

Unfunded Mandates Reform Act of 1995 

(2 U.S.C. 1501 et seq.) requires no 

further agency action or analysis. 

C. The Treasury and General 

Government Appropriations Act of 

1999: Assessment of Federal 

Regulations and Policies on Families 

This proposed rule would have no 

affect on family well-being or stability, 

marital commitment, parental rights or 

authority, or income or poverty of 

families and children. Accordingly, 

Section 654 of the Treasury and General 

Government Appropriations Act of 1999 

(5 U.S.C. 601 note) requires no further 

agency action, analysis, or assessment. 

D. Executive Order 12630: Government 

Actions and Interference With 

Constitutionally Protected Property 

Rights 

This proposed rule would not 

implement a policy with takings 

implications. Accordingly, Executive 

Order 12630, Governmental Actions and 

Interference with Constitutionally 

Protected Property Rights, requires no 

further agency action or analysis. 

E. Executive Order 12988: Civil Justice 

Reform 

This proposed rule was written to 

provide a clear legal standard for 

affected conduct and was carefully 

reviewed to eliminate drafting errors 

and ambiguities, so as to minimize 

litigation and undue burden on the 

Federal court system. Accordingly, this 

proposed rule would meet the 

applicable standards provided in 

Section 3 of Executive Order 12988, 

Civil Justice Reform. 

F. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

This proposed rule would have no 

adverse impact on children. 

Accordingly, Executive Order 13045, 

Protection of Children from 

Environmental Health Risks and Safety 

Risks, as amended by Executive Orders 

13229 and 13296, requires no further 

agency action or analysis. 

G. Executive Order 13132: Federalism 

This proposed rule would not have 

‘‘federalism implications,’’ because it 

would not ‘‘have substantial direct 

effects on the States, on the relationship 

between the national government and 

the States, or on the distribution of 

power and responsibilities among the 

various levels of government.’’

Accordingly, Executive Order 13132, 


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Federalism, requires no further agency 

action or analysis. 

H. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This proposed rule would not have 

‘‘tribal implications,’’ because it would 

not ‘‘have substantial direct effects on 

one or more Indian tribes, on the 

relationship between the Federal 

government and Indian tribes, or on the 

distribution of power and 

responsibilities between the Federal 

government and Indian tribes.’’

Accordingly, Executive Order 13175, 

Consultation and Coordination with 

Indian Tribal Governments, requires no 

further agency action or analysis. 

I. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

Regulation of the metal/nonmetal 

sector of the mining industry has no 

significant impact on the supply, 

distribution, or use of energy. This 

proposed rule is not a ‘‘significant 

energy action,’’ because it would not be 

‘‘likely to have a significant adverse 

effect on the supply, distribution, or use 

of energy * * * (including a shortfall in 

supply, price increases, and increased 

use of foreign supplies).’’ Accordingly, 

Executive Order 13211, Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use, requires no further 

agency action or analysis. 

J. Executive Order 13272: Proper 

Consideration of Small Entities in 

Agency Rulemaking 

We have thoroughly reviewed this 

proposed rule to assess and take 

appropriate account of its potential 

impact on small businesses, small 

governmental jurisdictions, and small 

organizations. As discussed in Section 

XI of this preamble, we have determined 

and certified that this proposed rule 

would not have a significant economic 

impact on a substantial number of small 

entities. Accordingly, Executive Order 

13272, Proper Consideration of Small 

Entities in Agency Rulemaking, requires 

no further agency action or analysis. 

XIV. Proposed Rule Text 

List of Subjects in 30 CFR Part 57 

Diesel particulate matter, Metal and 

nonmetal, Mine safety and health, 

Underground miners. 

Dated: September 1, 2005. 

David G. Dye, 

Deputy Assistant Secretary of Labor for Mine 

Safety and Health. 

For reasons set forth in the preamble, 

we propose to amend Chapter 1 of Title 

30 as follows: 

PART —57 [AMENDED] 

1. The authority citation for part 57 

reads follows: 

Authority: 30 U.S.C. 811 

2. Section 57.5060 is amended by 

revising paragraph (b) and removing 

paragraph (c)(3)(i) to read as follows: 

§ 57.5060 Limit on exposure to diesel 

particulate matter. 

* * * * * 

(b)(1) Effective January 20, 2006, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 308 

micrograms of elemental carbon per 

cubic meter of air (308EC μg/m3). 

(2) Effective January 20, 2007, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 350 

micrograms of total carbon per cubic 

meter of air (350TC μg/m3). 

(3) Effective January 20, 2008, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 300 

micrograms of total carbon per cubic 

meter of air (300TC μg/m3). 

(4) Effective January 20, 2009, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 250 

micrograms of total carbon per cubic 

meter of air (250TC μg/m3). 

(5) Effective January 20, 2010, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 200 

micrograms of total carbon per cubic 

meter of air (200TC μg/m3). 

(6) Effective January 20, 2011, a 

miner’s personal exposure to diesel 

particulate matter (DPM) in an 

underground mine must not exceed an 

average eight-hour equivalent full shift 

airborne concentration of 160 

micrograms of total carbon per cubic 

meter of air (160TC μg/m3). 

* * * * * 

[FR Doc. 05–17802 Filed 9–6–05; 8:45 am] 

BILLING CODE 4510–43–P