**METAL AND NONMETAL DIESEL PARTICULATE MATTER (DPM) STANDARD**

**Compliance Guide Q&As**

**Issued June 2006**

Comments/questions may be sent by e-mail to <Cash.Doris@dol.gov>

or mailed to:

Doris Cash\
Metal/Nonmetal Mine Safety and Health, Health Division, Room 2451\
1100 Wilson Blvd.\
Arlington, VA 22209-2296

phone: 202-693-9631

**[INTRODUCTION ‑ HOW TO USE THIS PUBLICATION]{.underline}**

This document is presented in a question and answer format with the
questions asked from the perspective of the mine operator. The terms
\"standard\" and \"rule\" are interchangeable and mean the same thing in
this guide.

1.  **Who should use this publication?**

This publication is intended to provide compliance information to
underground mine operators, miners, and representatives of miners in
metal and nonmetal underground mines that use diesel powered equipment.

2.  **What is the purpose of this guide?**

This guide provides a summary of the requirements of the Mine Safety and
Health Administration\'s (MSHA's) standard on Diesel Particulate Matter
Exposure of Underground Metal and Nonmetal Miners. This guide also
contains compliance assistance information to help you meet current
requirements of the standard.

[HEALTH RISKS]{.underline}

3.  **What is DPM and why is MSHA regulating it?**

DPM is a component of diesel exhaust. DPM includes diesel soot and solid
aerosols such as organic carbon compounds, ash, metallic abrasion
particles, sulfates and silicates. The majority of diesel exhaust
particles are less than 1.0 μm in size. Diesel soot particles have a
solid core mainly consisting of elemental carbon, with a wide variety of
other substances attached to the surface.

Exposure to high concentrations of DPM can result in a variety of
serious adverse health effects. These health effects have been found to
include: (i) sensory irritations and respiratory symptoms serious enough
to distract or disable miners; (ii) premature death from cardiovascular,
cardiopulmonary, or respiratory causes; and (iii) lung cancer. The
health effects are discussed in the January 2001 and the June 2005
preambles.

**[SCOPE OF THE DPM STANDARD]{.underline}**

4.  **What mine operators will have to comply with this standard?**

The standard applies to all operators of underground metal and nonmetal
mines that use diesel powered equipment in the underground areas of the
mine. This includes certain independent contractors that use diesel
powered equipment underground in metal and nonmetal mines.

Independent contractors whose diesel powered vehicles enter underground
areas of a mine on a frequent, regular, and recurring basis, or remain
inside the mine for a prolonged period of time are covered under the
requirements of this standard because such equipment would be considered
to be part of the mine\'s diesel equipment fleet. Examples of such
contractors include a mining contractor that has been hired to handle a
mine's production haulage using its own haulage trucks, or a blasting
contractor that uses its own powder truck to load blast holes at a mine.
These vehicles and equipment are used on a regular basis underground,
and the contractor's employees as well as the mine operator's employees
would be exposed to DPM hazards. MSHA intends that contractor employees
be protected from hazards from DPM exposure.

5.  **Are customer and delivery vehicles covered under the standard?**

No. Delivery and customer vehicles are not covered by the requirements
of this standard. For example, contractors such as an electrical
contractor vehicle that is brought into a mine to install a new power
center, or an equipment dealer's service truck that is brought into a
mine to maintain a new loader are not covered under the DPM standard.
Mine operators may need to restrict emissions from customer vehicles in
order to reduce miners' exposures to the PEL.

6.  **Does the standard apply to gasoline-powered vehicles and
    equipment?**

No. Only diesel powered vehicles and equipment used underground are
covered.

7.  **Does the standard apply to active underground mines that are not
    in production?**

Yes. The standard applies to active underground mines that are in
development, undergoing rehabilitation and mines engaged in exploratory
activities.

8.  **What are the provisions of the DPM rule in effect now?**

§ 57.5060(b), addressing the final concentration limit

-   effective May 20, 2006, the final PEL is 308~EC~ μg/m^3^

-   effective January 20, 2007, the final PEL is 350~TC~ μg/m^3^

-   effective May 20, 2008, the final PEL is 160~TC~ μg/m^3^

> § 57.5060(c), Extension of time in which to meet the final
> concentration limit.

§ 57.5060(d), Use of feasible controls and respiratory protection

-   install, use, and maintain feasible engineering and administrative
    controls

-   supplement with respiratory protection

-   [effective on August 16, 2006:]{.underline}

    -   conforming changes to the introductory text

    -   new paragraphs (d)(3) through (d)(8) regarding medical
        evaluation of miners required to wear respiratory protection and
        transfer of miners who are medically unable to wear a
        respirator.

§ 57.5060(e), Prohibition on rotation of miners

§ 57.5061, Compliance determinations

§ 57.5065, Fueling practices

§ 57.5066, Maintenance standards

§ 57.5067, Engines

§ 57.5070, Miner training

§ 57.5071, Exposure monitoring

§ 57.5075, Diesel particulate records

Note: The effectiveness of § 57.5060(a) has expired.

9.  **Why is the initial final limit EC and the other final limits are
    TC?**

In 2005, we converted the 400 μg/m^3^ total carbon limit to 308 μg/m^3^
elemental carbon.

We are committed to initiating a separate rulemaking to determine the
most appropriate conversion of the other final TC limits to comparable
EC limits.

10. **If the purpose of the rule is to limit a miner\'s exposure to DPM,
    why does the standard restrict exposure to elemental carbon?**

MSHA is unaware of an appropriate sampling and analytical method that
can accurately and precisely measure field samples of whole DPM at the
concentrations required for compliance determinations. MSHA therefore
measures miners\' exposures to DPM by analyzing samples for a component
of DPM that can be accurately and precisely measured. The component of
DPM that MSHA will analyze, called the \"surrogate,\" is elemental
carbon (EC). The carbon in diesel soot is present in two forms:
elemental carbon and organic carbon. The analytical method that MSHA
uses for DPM analysis is capable of individually measuring both the
elemental and organic carbon captured on the sample filter. The sum of
the elemental carbon and organic carbon (OC) is total carbon. MSHA will
use the EC measurement as the surrogate to ensure that the result is
representative of DPM without interferences.

11. **How many samples will MSHA use to determine a miner's exposure?**

MSHA will determine a miner's exposure with a single full-shift sample.

12. **Will MSHA sample a miner's exposure for less than the full
    shift?**

No. All of MSHA's compliance samples will be collected for the affected
miner's full-shift.

13. **How will MSHA determine a miner\'s overexposure to the final
    elemental carbon limit of 308 μg/m^3^?**

MSHA will determine compliance with the EC limit based on a single
full-shift personal sample of the affected miner. If the result of the
EC measurement is above the final limit of 308 micrograms plus the error
factor, then an overexposure has occurred.

### MSHA will determine an overexposure of the final DPM limit follows:

## 308 micrograms EC limit enforced as a PEL

## 

EC result is **less than or equal to \[308 x error factor\]** = Not an
overexposure.

EC result is **greater than \[308 x error factor\]** = An overexposure
has occurred.

14. What is the error factor?

As with all other exposure-based metal/nonmetal compliance
determinations, MSHA will address uncontrollable sampling and analytical
errors by allowing a margin of error before issuing a citation for
exceeding the elemental carbon (EC) limit. MSHA has developed an
appropriate error factor to account for variability in sampling and
analysis from such things as pump flow rate, filters, and the NIOSH 5040
method. If the EC measurement is above 308 µg/m^3^ times the error
factor for EC (1.12), the miner is overexposed.

15. **What is meant by "average eight-hour equivalent full shift
    airborne concentration"?**

"Average full shift airborne concentration" means that a miner's
exposure is determined by measuring the average concentration of
airborne DPM to which the miner is exposed over a full work shift,
regardless of shift length. Temporary excursions above a limit are
permitted from time to time during the shift, as long as the average
over the entire shift is within the limit.

The term, "average eight hour equivalent full shift airborne
concentration," refers to MSHA's longstanding practice of
"shift-weighting" when applying compliance limits for airborne
contaminants to exposures that occur over a time period that is
different from a standard 8-hour shift. MSHA's compliance limits are
normally based on 8 hours of workplace exposure to a contaminant and 16
hours of recovery time in the absence of the contaminant. The workplace
8-hour shift weighted average (SWA) exposure is computed as the mass of
DPM on the filter divided by the 8-hour sample volume, which is 0.816
cubic meter for a sample flow rate of 1.7 liters per minute.

Actual concentrations are computed using actual sampling times; the SWA
is adjusted to the 8-hour shift equivalent using the following equation:

[actual shift length (in minutes)]{.underline}

SWA = measured concentration of DPM x 480 minutes

16. **How will MSHA determine a miner\'s overexposure to the final total
    carbon limits of 350 μg/m^3^ and 160 μg/m^3^?**

We intend to use the 1.3 conversion factor to convert the 350~TC~
μg/m^3^ final limit to an EC equivalent. As we did with the 400~TC~
μg/m^3^ interim limit pursuant to the Second Partial Settlement
Agreement, we will use the EC equivalent to validate that an
overexposure to the 350 TC limit is not the result of interferences. We
will first develop an appropriate error factor to account for
variability in sampling and analysis from such things as pump flow rate,
filters, and the NIOSH Analytical Method 5040.

If the TC measurement is below 350~TC~ µg/m^3^ plus the error factor, we
will not issue a citation for an overexposure. If the TC measurement is
above 350~TC~ µg/m^3^ times the error factor, we would look at the EC
measurement from the sample obtained through the NIOSH Analytical Method
5040, and multiply EC by a factor of 1.3 to produce a statistical valid
estimate of what the TC result is without interferences. If the TC
measurement is above this estimate, we would not issue a citation when
the EC measurement times the multiplier is below the TC analysis.

The 1.3 multiplier that we will use to estimate TC (i.e., EC x 1.3 =
estimated TC) is derived from NIOSH\'s determination that TC is 60-80%
EC.

Regarding enforcement of the 160 μg/m^3^ , MSHA intends to initiate a
rulemaking to convert the TC limit to an equivalent EC limit.

**§ 57.5060(c), extension of time in which to meet the final
concentration limit**

17. **What may I do if I require additional time to come into compliance
    with the final DPM concentration limit established in § 57.5060
    (b)?**

If you require additional time to come into compliance with the final
DPM limit established in § 57.5060(b) due to technological or economic
constraints, you may file an application with the District Manager for a
special extension. If the District Manager grants you a special
extension, you must comply with the conditions of the extension for its
duration. We will periodically check to determine current DPM exposures
and your ability to implement new control technology.

18. **When can I apply for a special extension?**

You may apply for an extension any time you believe that you have
technological or economic constraints in meeting the final DPM limits.

19. **How much extra time will a special extension give me to come into
    compliance with the final limit?**

A special extension is not a substitute for required feasible controls.
No special extension can exceed a period of one year from the date of
approval. You may, however, file for additional special extensions
provided each extension does not exceed a period of one year. If,
however, controls become feasible at any time while the extension is in
effect, you must implement those controls.

20. **If the next lower final limit goes into effect before the one year
    is up, do I have to re-apply?**

If MSHA has determined it was infeasible for you to achieve compliance
with the applicable PEL, it would likewise be infeasible for you to
achieve compliance with a lower PEL. The extension would remain in
effect for the period granted. If, however, controls become feasible at
any time the extension is in effect, you must implement those controls.

21. **How will MSHA determine whether to grant the special extension?**

MSHA will consider both economic and technological feasibility when
determining whether operators qualify for a special extension for the
final concentration limit. Technological and economic feasibility must
be assessed on a case-by-case basis. Therefore, you will have an
opportunity to demonstrate that there is no cost-effective solution to
reducing a miner's exposure to DPM. The District Managers are more
knowledgeable of the specific conditions and circumstances that exist at
mines within their regions rather than Headquarters. Consequently, MSHA
has determined that they are the appropriate entity to assess technical
and economic feasibility issues at mines.

When determining whether to grant a special extension for complying with
the final concentration limit, MSHA will apply the criteria of the
standard. MSHA will conduct an analysis of the circumstances at a mining
operation to determine whether the mine operator has exhausted all
feasible engineering and administrative controls before using
respiratory protection to supplement controls. Such an evaluation will
involve consideration of certain factors, including specific mining
conditions, type of mining equipment used, nature of the overexposure,
controls used by the mine operator, and MSHA policy and case law
governing the economic and technological feasibility of controls.

Upon receipt of an application for a special extension, the MSHA
District Manager will initiate a review of your application. In making
this determination, the District Manager may ask you to provide
additional information, conduct additional sampling and on-site
evaluation, and request the assistance of personnel in MSHA's
Directorate of Technical Support.

22. **What do I have to include in my application for a special
    extension?**

An application for an extension must include information that explains
why you believe engineering and administrative controls sufficient to
achieve compliance with the applicable limit are economically or
technologically infeasible. The application also must include the most
recent DPM monitoring results, and specify the actions you intend to
take during the extension period to minimize exposure of miners to DPM.
These actions will include the requirement for you to implement and
maintain engineering and administrative controls as they become feasible
during the period of extension.

Supporting documentation should include sufficient information for MSHA
to determine that controls are technologically or economically
infeasible, such as specific cost data, unique mining conditions,
implementation difficulties, effects on productivity, unavailability of
controls, miners' DPM exposures, the occupations and mine areas for
which you are seeking an extension of time to come into compliance, and
any other relevant information. The actions you will be taking to
minimize the exposure of miners to DPM should include such items as
monitoring, maintaining controls and respiratory protection, and other
good faith actions.

> You must also certify on the application that you have posted one copy
> of the application at the mine site for at least 30 days prior to the
> date of application, and have provided another copy to the authorized
> representative of miners.

23. **Do I have to post the application before I file it with the
    District Manager?**

Yes. You must post one copy of the application at the mine site for at
least 30 days prior to the date of application, and provide a copy to
the authorized representative of miners.

24. **What must I do if the application for a special extension is
    approved?**

You must comply with the terms of the approved application for a special
extension for the duration of the extension. You must also post a copy
of the approved application at the mine site for the duration of the
special extension period, and provide a copy of the approved application
to the authorized representative of miners.

MSHA does not intend for the 1-year period of an extension to be
considered as the period of abatement that the Agency will establish for
noncompliance citations pursuant to § 57.5060. When MSHA issues a
citation for a miner's overexposure to DPM, we apply a time frame for
abatement of the citation based on our assessment of specific
circumstances at each mine.

25. **Do the affected miners have to wear respirators under a special
    extension?**

Yes. Where an extension is granted, overexposed miners will be required
to wear respiratory protection under a respiratory protection program as
specified in

§ 57.5060(d).

26. **Do I have to maintain engineering and administrative controls
    under a special extension?**

Yes. MSHA does not intend for PPE to be permitted during an extension
period as

a substitute for feasible engineering and administrative controls.
Rather, you are required to implement all feasible engineering and
administrative controls to reduce

exposures to the applicable limit, or if that is not possible, to the
lowest level feasible.

27. **What may I do if my application for a special extension is denied
    by the District Manager?**

MSHA believes that the Mine Act currently affords mine operators
adequate due process rights to a hearing on the merits before an
administrative law judge (ALJ) of the independent Federal Mine Safety
and Health Review Commission. If you disagree with the ALJ's decision,
you may request an appeal before the Commission, which is composed of
five independent commissioners. Any person adversely affected by a
determination of the Commission may obtain review from a U.S. court of
appeals for the applicable circuit.

**§ 57.5060(d) USE OF FEASIBLE CONTROLS**

28. **What is the difference between DPM engineering controls and
    administrative controls?**

Engineering controls refer to controls that remove the DPM hazard from
the workplace by applying such methods as substitution, isolation,
enclosure, and ventilation. Installing engine exhaust filters and
cleaner burning engines, the use of special fuels or fuel additives that
reduce DPM emissions, de-rating engines, providing environmental cabs
with filtered breathing air, and mine ventilation system upgrades (main
or auxiliary) would be examples of engineering controls.

Administrative controls refer to specified changes in the way work tasks
are performed that reduce or eliminate the hazard. Speed limits, one-way
travel, prohibitions on unnecessary idling or lugging of engines,
restrictions on the number of engines or total engine horsepower that
would be allowed to operate in a given ventilation split at any one
time, and designating areas that are "off limits" for diesel engine
operation or personnel travel are examples of administrative controls.

29. **How will MSHA determine whether engineering and administrative
    controls are feasible?**

For purposes of determining feasibility of engineering and
administrative controls, MSHA will assess both the technological and
economic feasibility of reducing a miner\'s

exposure to the interim DPM limit. MSHA will apply the same test as
established by the Mine Safety and Health Review Commission (Commission)
in ruling that a noise control is considered feasible when it:

-   reduces exposure;

-   is technologically achievable; and

-   is economically achievable.

Consistent with Commission case law, MSHA considers three factors in
determining whether engineering controls are feasible at a particular
mine: (1) the nature and extent of the exposure; (2) the demonstrated
effectiveness of available technology; and (3) whether the committed
resources are wholly out of proportion to the expected results. A
violation under the final standard would entail MSHA determining that a
miner has been overexposed, that controls are feasible, and that you
failed to install and maintain such controls.\
\
The Commission further ruled that a control need not reduce exposure
below the PEL in order to be feasible, as long as there is a significant
reduction. Sometimes, however, a single control may achieve less than a
significant reduction and still be considered feasible if its use, in
combination with other controls, achieves a significant reduction.

30. **Is job rotation allowed for compliance with the DPM standard?**

No. The DPM standard prohibits rotation of miners to achieve compliance
with the DPM PEL.

31. **Will MSHA restrict the practice of having a miner work in a job
    assignment that requires the miner to split their shift between
    surface and underground or to perform more than one job
    underground?**

No, unless the split shift is established to comply with the DPM rule.
MSHA recognizes that a number of mining operations routinely require
their miners to work on both the surface and underground or to perform
more than one job for reasons not involving compliance with DPM. MSHA
would allow this practice to continue.

32. **What is a significant reduction?**

MSHA considers a significant reduction in DPM to be at least a 25%
reduction in the miner\'s exposure.

33. **How long will MSHA give me to implement controls?**

In every case, MSHA intends to establish reasonable abatement time
frames for compliance. MSHA makes this decision on a case-by-case basis
depending on the facts of the particular situation. For example, if a
mine operator decides to utilize after-treatment devices to reduce DPM
exposure levels, MSHA would consider the amount of time required to
order and receive the devices as well as the time to install and fully
implement the devices.

34. **If MSHA finds a miner overexposed to DPM and I have a valid
    purchase order for controls that have not be delivered to my mine
    site, will I be cited for a violation?**

No. If you can demonstrate to MSHA, through appropriate documentation
such as purchase orders, that you are making reasonable progress toward
implementing feasible engineering and/or administrative controls that
have a reasonable likelihood of achieving compliance with the final DPM
limit within a reasonable timeframe, and you have implemented a
respiratory protection program meeting the requirements of § 57.5060(d)
that covers all affected miners, MSHA will not conduct compliance
sampling of affected miners at that time. The inspector will return to
the mine to verify that adequate progress is being made toward full
implementation of controls and/or to conduct DPM sampling based on the
projected timeframe established by the mine operator for implementing
the controls.

Note that such efforts to implement feasible engineering and/or
administrative controls for DPM do not exempt a mine operator from
complying with the other provisions of the standard, such as use of low
sulfur fuel and EPA-registered fuel additives, the

maintenance and engine provisions, providing required DPM training, and
the recordkeeping requirements.

35. **How will MSHA evaluate feasibility of controls in determining
    whether to issue a citation for a miner's overexposure to the PEL?**

Once you use and maintain all feasible engineering and administrative
controls to reduce a miner\'s exposure, implement the required
respiratory protection program and require the miner to use a
respirator, you are in compliance with § 57.5060(b), even though a
miner\'s DPM exposure may continue to exceed the limit and a citation
will not be issued. Note that you must have a physician or other
licensed health care professional (PLHCP) conduct a medical evaluation
of a miner who is required to wear a respirator before the miner is fit
tested.

Keep in mind that feasibility is an MSHA determination. If the agency
finds that you failed to install, use and maintain all feasible
controls, or you failed to establish an appropriate respiratory
protection program, you will be out of compliance.

**[Diesel Particulate Filters]{.underline}**

36. **If I determine that I need to install a DPM filter system on a
    piece of equipment to reduce DPM emissions, how do I know what type
    of DPM filter to purchase?**

The majority of the commercially available DPM filter media are either
cordierite or silicon carbide. However, both filter media have similar
filtering efficiencies. The ceramic media can be used directly in the
engine's hot exhaust. The correct cleaning or regeneration method for
the DPM filter is dependent on a machine's intended use and duty cycle,
as well as the make and model of its diesel engine. MSHA strongly
suggests mine operators consult with their engine manufacturer and
filter supplier before making a selection. Additionally, MSHA worked
with NIOSH to develop a \"Diesel Particulate Filter Guide\" which can be
used by mine operators in decision making for filter selection. The
\"Filter Guide\" can be found at the following MSHA Internet address:

<http://www.msha.gov/nioshmnmfilterselectionguide/dpmfilterguide.htm>

Another significant tool for you to use is the \"Best Practices.\" MSHA
and NIOSH developed this compliance assistance tool so that you will
have appropriate information on proper use and installation. These files
present information based on in-mine use experience with DPM filters and
can be found at the following MSHA Internet address:
<http://www.msha.gov/nioshmnmfilterselectionguide/dpmfilterguide.htm>

Finally, NIOSH has implemented a \"List Server.\" The list-server is a
means to disseminate and share information and experiences concerning
the application of available technologies for reducing miners' exposures
to DPM and other gaseous emissions in underground mines. Anyone can sign
up at no cost to share and receive information. The Internet address is
posted on MSHA's web site at:
<http://www.msha.gov/01-995/nioshlserve/nioshlserve.htm>

In some cases, even a properly selected and installed filter may not
function exactly as anticipated by the mine operator. For example, if a
filter is selected based on the assumption that passive regeneration
will occur due to a machine's heavy duty cycle, but then that machine is
shifted to another job having a light or mixed duty cycle, the expected
passive regeneration will probably not occur.

37. **Are DPM filters suitable for retrofitting on my existing diesel
    powered equipment?**

Yes. Properly selected and maintained filters work in many applications.
Commercially available diesel particulate filter (DPF) systems may be
suitable for retrofitting to existing diesel-powered equipment in
underground metal and nonmetal mines to effectively reduce miners\'
exposures to DPM. You will need to work through technical and
operational situations unique to your specific mining circumstances. For
example, equipment subject to heavy-duty cycle operating conditions may
be suitable candidates for passively regenerated filters, whereas
lighter duty cycle applications would likely require actively
regenerated filters.

You should, however, be aware that older engines, especially ones that
are emitting black smoke or burning excessive engine oil, may not be
suitable candidates for DPFs. High amounts of DPM emitted from older
engines may overload a DPF too quickly, thus reducing the ability of the
DPF to regenerate properly. Mine operators should consult with the DPF
manufacturers to determine if an engine is suitable for retrofit with a
DPF.

38. **How does a ceramic DPM filter work?**

Several ceramic DPM filter designs have been developed. One design,
referred to as a ceramic monolith type filter, consists of a "honeycomb"
arrangement of long, small diameter parallel hollow ceramic-walled
tubes. Alternate tubes are sealed on one end and open on the other end
in a "checkerboard" pattern. The filter assembly is placed in-line into
the exhaust system. DPM laden exhaust enters the open ends of the tubes
and the DPM collects on the sidewalls, unable to pass through the porous
filter media. The exhaust gases pass through the porous sidewalls of the
tubes into the adjacent tubes, which are open only on their downstream
ends. The gases exit through the exhaust pipe downstream of the filter.

39. **How do you clean the ceramic type filters?**

The ceramic filter collects and stores DPM. Cleaning the filter requires
a source of heat to burn the DPM off of the filter media. Cleaning of
the filter, referred to as "regeneration," is either accomplished by a
passive, active, or combination

passive/active method.

40. **What happens if a ceramic filter is not properly cleaned?**

If ceramic filters are not properly cleaned (regenerated), the filter
can become overloaded and clogged with DPM, thus causing excessive
exhaust backpressure and possibly leading to uncontrolled combustion of
the accumulated soot (uncontrolled regeneration) and destruction of the
filter. The engine manufacturers specify maximum backpressure allowed on
their engines. An engine warranty can be voided if the engine is
operated with excessive backpressure, and ultimately, filter failure and
engine damage can occur.

Uncontrolled regeneration occurs when an excessively large amount of
soot in the ceramic filters starts to combust due to a sustained period
of heavy engine loading followed by light engine loads. The combustion
temperature rises beyond the melting point of the ceramic or a hot spot
develops that either melts or cracks the ceramic.

41. **What can be done to avoid uncontrolled regeneration of a ceramic
    DPM filter?**

The magnitude of the backpressure on the engine provides an indication
of the loading on the filter, so continuous monitoring of the
backpressure enables users to take appropriate action to clean or remove
the filter before filter overloading and resultant filter failure and
engine damage occur. DPM filters are available that are provided with
appropriate pressure sensors, enabling continuous monitoring of filter
backpressure.

42. **What is passive regeneration?**

Passive regeneration means the filter is cleaned while it is installed
on the machine and the machine operates through its normal work cycle.
The hot exhaust gas actually causes accumulated DPM to combust. This
combustion converts the solid particulates to combustion gases, which
pass through the filter and out through the exhaust pipe. For passive
regeneration to work properly, the exhaust gas temperature must exceed a
certain minimum value for a certain percentage of the work shift,
typically around 400°C to 425°C for about 25 percent of the shift.

43. **Why is a catalyst usually needed for passive regeneration?**

The catalyst promotes filter regeneration at a lower exhaust gas
temperature, thereby facilitating passive regeneration under load
conditions that would otherwise not achieve sufficient engine exhaust
temperature for passive regeneration to occur. A catalyst may be added
to the fuel (fuelborne) or may be coated onto a DPM filter. Filters may
be coated with either a precious metal catalyst or a base metal
catalyst. However, using a catalyst can only reduce the required exhaust
temperature somewhat. Achieving successful passive regeneration on light
duty equipment is often impossible. Filter manufacturers should be
contacted for further information on specific products or users can
consult the MSHA homepage at [www.msha.gov](http://www.msha.gov/).

Certain platinum based catalyzed filters can also cause an increase in
nitrogen dioxide (NO~2~) emissions due to the conversion of nitric oxide
(NO) to NO~2~. The mine operator should be aware of this when using
these devices. MSHA has issued a program information bulletin on its web
site addressing this issue.

44. **What is active regeneration?**

Active regeneration occurs when the filter is cleaned by a heat source
other than the engine's exhaust gas temperature. This is normally done
using an external electrical heat source, fuel additive, oven, or diesel
fuel burner. Regeneration can be done while the filter is on the machine
(on-board active regeneration) or the filter can be taken off the
machine (off-board active regeneration) depending on the filter
manufacturer's active regeneration system. Active regeneration normally
requires two to four hours, and some provision for handling hot exhaust
gases from the active regeneration process may be necessary. In some
applications, equipment operators will need to be instructed and trained
to engage the external heat source at the end of their shifts.

45. **What is passive/active regeneration?**

Passive/active regeneration is a combination of both regeneration
systems. For example, this has been done with base metal catalyzed
traps, uncatalyzed traps with fuelborne additives, or combinations of
these two systems, where the engine produces exhaust gas temperature
that can burn off almost, but not quite all of the DPM. In this case,
the DPM slowly builds up so that at a certain extended time interval,
once every 250 hours, for example, based on backpressure or the
maintenance schedule, the filter is removed for cleaning in a
"regeneration station" or remains in place and is cleaned using on-board
electric heaters.

46. **How do I know if my machine can produce enough heat for passive
    regeneration?**

To determine if a machine is suitable for passive regeneration, an
exhaust gas temperature trace must be performed. This is done by
measuring the exhaust gas temperature with a thermocouple and a data
logger during the working shift. This will indicate the exhaust gas
temperature that the machine is developing during the working shift, and
for how long various temperature levels are maintained. The filter
manufacturer can review this data to assist the mine operator in
purchasing the correct filter with the correct regeneration system. MSHA
has also posted some guidelines on this subject on their web site.

47. **How often do I have to clean the filter?**

Exhaust backpressure is the best indicator for determining when the DPM
filter needs to be cleaned. As noted above, the engine manufacturer
specifies a maximum allowable exhaust backpressure for their engine.
This backpressure should never be exceeded in order to prevent engine or
filter damage.

48. **Where should I install the filter in the exhaust system?**

The filter manufacturer should be able to assist you with exact
location. For passive or passive/active regeneration filters, the filter
should be installed close to the outlet of the exhaust manifold or the
turbocharger in order for the filter to be exposed to the highest
possible exhaust gas temperature. For active regeneration filter
systems, the location is not as important since the filter does not
depend on the exhaust gas temperature for heat for regeneration.

49. **If I install a ceramic filter, how do I know it is working
    properly?**

A quick qualitative check can be made by observing the engine exhaust
for signs of diesel soot, especially when the engine is operating under
heavy load or lugging conditions. An adequate indicator of the amount of
soot being passed by the filter is available. This device samples the
exhaust through a white paper filter and the "grayness" of the spot is
compared to a 0 to 9 "grayness" scale.

The entire exhaust system should be checked for leaks too, especially
upstream of the filter. Look for soot shadows at the joints. If the
exhaust system is leak tight, and the exhaust pipe at the exit of the
filter is clean on the inside, the filter is effective in reducing the
ambient DPM from the machine by more than 85%. If a quantitative measure
of performance is needed, the best way is to operate the equipment in an
isolated zone with and without the filter installed, and sample the mine
atmosphere for DPM under both conditions.

50. **What do I do if I install a ceramic filter, and do everything
    possible to promote passive regeneration, but the filter won't
    passively regenerate?**

Despite every effort to achieve passive regeneration, in some cases,
especially light or mixed duty applications, passive regeneration is
simply not possible. In these cases, the filter will need to be cleaned
by other means. This may be considered less desirable and add
unanticipated costs and complexity to the process. However, users should
remember that the ultimate goal of filtering diesel exhaust is to remove
the DPM. As long as the DPM is removed at an acceptable efficiency, the
filter is "doing its job."

51. **Where do I install the backpressure monitoring device?**

The backpressure monitoring device should be installed ahead of the DPM
filter or catalytic converter in the exhaust pipe so it will provide the
total exhaust system backpressure.

52. **How often should I check the backpressure?**

The backpressure device should be set up so that the machine operator
can monitor the backpressure during machine operation. A mechanical
needle gauge or an electronic monitor that uses indicator lights to
provide the backpressure status can be installed in the operator's
compartment. In both cases, the tubing that connects the backpressure
device to the exhaust pipe must be maintained to prevent clogging.

53. **What conditions will prevent the backpressure from being
    accurately monitored?**

A blocked exhaust port will not allow the exhaust pressure to be
monitored. This can give the machine operator a false indication on the
status of the exhaust backpressure. If a needle gauge is being used, the
needle should always be moving. Absence of any movement in the gauge or
the gauge always reading "zero" or "low" would be an indication of a
blocked port. Holes in the DPM filter or leaky gaskets will allow the
exhaust to pass around the filter and minimize the backpressure. In this
case, the backpressure will never increase because the DPM filter is not
trapping the DPM.

54. **What other maintenance should be performed on the backpressure
    monitoring line?**

Since exhaust gas contains water vapor, when the exhaust starts to cool
in the backpressure line, the water will condense to liquid. The exhaust
backpressure line should contain a water drop out bowl. However, the
drop out bowl can become full or clogged and prevent the backpressure
from being properly monitored. This drop out bowl should be checked
prior to machine operation.

55. **How can I tell if the electronic backpressure monitoring lights
    are working?**

Electronic backpressure monitors can become ineffective in the same way
as mechanical needle gauges if the ports or lines are blocked. Some mine
operators install a mechanical needle gauge along side the electronic
device as a backup. As stated above, a needle gauge should always being
moving. Lack of movement would indicate a blocked port. A maintenance
person could check the lines and the electronic device by using
compressed air to add pressure to the monitoring devices through the
lines. However, you must be careful not to apply too much air and damage
the gauges.

56. **After the DPF is regenerated, what causes the exhaust backpressure
    to not return to as low as it was the last time the DPF was
    regenerated?**

The regeneration cycle, either passive or active, burns off the DPM
which is mainly carbon. However, over time the filter loads up with ash
and metals from the oil and engine wear. The ash and metals cannot be
removed by the regeneration process. The filter manufacturer should
provide the proper schedule and procedure for DPF cleaning to remove the
ash and metals. If the ash and metal are not removed, the DPF will
eventually clog which could lead to DPF or engine damage.

**[BIODIESEL]{.underline}**

57. **What is biodiesel?**

Biodiesel is an EPA registered diesel fuel and diesel fuel additive made
from feedstocks such as soy oil, cottonseed oil, peanut oil, rape seed
oil, or animal fat. It can be made from these products before (virgin)
or after they have been used as cooking oils (recycled oil or yellow
grease). The virgin or recycled oils themselves cannot be used as diesel
fuel. These oils need to be reacted with alcohol (methanol or ethanol)
in the presence of a catalyst (sodium or potassium hydroxide) to remove
the glycerin. The resulting product, consisting of mono-alkyl esters, is
biodiesel, and it can either be mixed with standard #1 or #2 petroleum
diesel or used in 100% (neat) form.

The applicable ASTM standard for biodiesel is D6751-06, "Standard
Specification for Biodiesel Fuel (B100) Blend Stock for Distillate
Fuels," which establishes minimum requirements for fuel quality and
properties. Biodiesel meets clean diesel standards established by the
California Air Resources Board (CARB). Neat biodiesel has been
designated as an alternative fuel by the Department of Energy (DOE) and
the U.S. Department of Transportation (DOT).

58. **Will the use of biodiesel fuel reduce my DPM emissions?**

Yes. Depending on the fuel blend used, biodiesel has been shown to
significantly reduce DPM emissions in underground M/NM mines. Generally,
higher biodiesel content fuel blends produce lower DPM emissions, with
neat (100%) biodiesel producing the lowest DPM emissions. Fifty-percent
blends can reduce DPM emissions by 15 to 65 percent compared to standard
diesel fuel.

59. **Besides reduced DPM emissions, are there other benefits of using
    biodiesel fuel?**

Yes. Biodiesel has greater lubricity than standard petroleum diesel.
Tests have shown that even in blends as low as B2, biodiesel can restore
the lubricity of the poorest lubricity diesel fuel, including ultra low
sulfur diesel fuel. Biodiesel has a very low sulfur content, and can be
blended with ultra low sulfur diesel. Other benefits include lower
emissions of carbon monoxide, carbon dioxide, polycyclic aromatic
hydrocarbons, oxides of sulfur, and total hydrocarbons. Depending on the
fuel blend, engine, operating practices, maintenance, duty cycles, etc.,
oxides of nitrogen could be somewhat increased or somewhat decreased.

Biodiesel has a higher flash point than standard petroleum diesel for
greater storage and handling safety, and a higher cetane number for
better cold starts. The solvent and cleaning properties of biodiesel,
which are discussed in detail below, also promote better engine
performance by keeping the fueling system and injectors clean. Biodiesel
is also biodegradable and nontoxic.

60. **What is meant by biodiesel fuel blend?**

Biodiesel is often blended with standard petroleum diesel prior to sale.
Typical blends are 2% biodiesel mixed with 98% standard diesel (B2), 20%
biodiesel mixed with 80% standard diesel (B20), and 50% biodiesel mixed
with 50% standard diesel (B50). Biodiesel can also be used in neat or
100% form, or blended with very low concentrations of standard diesel,
such as 99% biodiesel mixed with 1% standard diesel (B99) or 99.9%
biodiesel mixed with 0.1% standard diesel (B99.9).

61. **What is the purpose of blending such small concentrations of
    standard diesel into biodiesel?**

At the present time, and at least through the year 2008, a federal
excise tax credit is available to blenders of biodiesel fuel. The credit
is equal to 1¢ per gallon for each % biodiesel in a fuel blend when the
biodiesel is made from virgin feedstocks, and 0.5¢ per gallon for each %
biodiesel in a fuel blend when the biodiesel is made from recycled oils.
To qualify for this blender's credit, the biodiesel must be blended with
standard diesel in a proportion of at least a 99.9% biodiesel to 0.1%
standard diesel (equivalent to 1 gallon of standard diesel in 999
gallons of biodiesel). For a 99.9% blend of virgin biodiesel (B99.9),
this tax credit amounts to roughly \$1.00 per gallon.

62. **Do I need to modify my engines in order to use biodiesel?**

Generally, any diesel engine can use biodiesel fuel without any engine
modifications. Due to the solvent properties of biodiesel, some
elastomeric components of a vehicle's fueling system such as hoses and
gaskets can be damaged by biodiesel, and may therefore need to be
replaced with biodiesel-compatible parts. For biodiesel fuel blends with
greater than 20% biodiesel content, Teflon and Viton can be used but
natural rubber, butyl rubber, Buna, nitrile, polyurethane, polypropylene
and polyvinyl are not acceptable materials. Users are cautioned to
contact the engine manufacturer or distributor to determine whether a
particular engine uses any parts that are not biodiesel-compatible, and
would need to be replaced.

63. **Will my engines perform as well on biodiesel?**

Neat or 100% biodiesel has about the same energy content as #1 petroleum
diesel, and 8-10% lower BTU content than standard #2 diesel. The lower
energy content of biodiesel results in lower power output delivered by
an engine fueled on biodiesel. This lower power output is generally not
noticeable when an engine runs on lower biodiesel content blends such as
B2 or B20. Lower power output will generally be noticeable only when an
engine runs on a higher biodiesel content blend and when the engine is
operated under heavy load, such as when a haulage truck travels upgrade
fully loaded.

When considering an entire duty cycle, which includes some heavy work,
some medium work, and some idle time, the overall effect of the lower
power output is not as great as the difference in BTU content between
biodiesel and standard #2 diesel. Mine operators that are using high
biodiesel content fuel blends such as B99 and B99.9 have reported no
negative effect on mine production.

64. **Will I use the same amount of fuel if I change to biodiesel?**

Biodiesel fuel consumption, measured on a gallons per hour basis, will
generally be higher than when the equipment operates on standard #2
diesel. In some cases, the higher lubricity and cleaning effect of
biodiesel compensate for the lower energy content of the fuel, with some
users reporting better fuel economy with biodiesel compared to standard
#2 diesel.

65. **Where can I buy biodiesel?**

At this time, biodiesel is available in every state except Alaska from
over 1400 commercial fuel distributors and over 750 retail filling
stations across the country.

66. **How can I be sure that if I switch to biodiesel, it will be
    available the next time I want to buy it?**

Biodiesel production was approximately 25 million gallons in the United
States in 2004 and approximately 75 million gallons in 2005. Biodiesel
plants under construction in 2006 were rated at 329 million gallons of
annual production capacity, and plants in the pre-construction phase in
2006 were rated at 518 million gallons of annual production capacity. An
on-line guide to buying biodiesel is maintained by the National
Biodiesel Board at the following internet web site:
<http://www.nbb.org/buyingbiodiesel/guide/default.shtm>

This web site includes up-to-date information on biodiesel production
facilities, commercial distributors, and retail filling stations
throughout the United States.

67. **How can I be sure that the biodiesel I purchase is always the same
    quality?**

It is strongly recommended that biodiesel in any blend be purchased from
a producer or distributor that adheres to BQ-9000 quality standards to
insure that fuel specifications meet or exceed ASTM D6751-06
requirements for fuel properties and quality. Off-specification fuel
exceeding maximum glycerin content specifications or failing to meet
other fuel quality requirements can adversely affect engine performance,
even in blends as low as B2. A BQ-9000 certification process has been
adopted by the National Biodiesel Accreditation Commission, and as of
June 2006, eight US biodiesel producers have become BQ-9000 certified.
The BQ-9000 certification process is a relatively recent development,
and many more producers are expected to become certified in the future.
To ensure that biodiesel meets minimum fuel quality standards,
purchasers should specify fuel that meets or exceeds the requirements of
ASTM D6751-06.

68. **What precautions do I need to take in cold weather if I wish to
    use a biodiesel fuel blend?**

For biodiesel fuel blends with greater than 20% biodiesel content,
precautions need to be taken in cold weather to prevent the fuel from
gelling. Neat, or 100% biodiesel made from virgin soy oil has a cloud
point of 32 degrees Fahrenheit and a pour point of 28 degrees
Fahrenheit. The cloud point is the temperature at which crystals begin
to form in the fuel, which could cause clogging of fuel filters. The
pour point is the temperature at which the fuel begins to solidify and
will not flow when poured. Where temperatures lower then 35 degrees
Fahrenheit are possible, fuel storage tanks need to be heated or located
in a heated structure.

Fuel transfer pipelines and fuel dispensing equipment also need to be
protected from cold temperatures. Mobile equipment that is exposed to
such temperatures, either during operations or between working shifts,
may need to be provided with fuel tank heaters, fuel line heaters, and
fuel filter heaters. Depending on the source of the biodiesel used in a
fuel blend, the cloud and pour points may be higher or lower than the
temperatures shown above. Users are urged to contact their fuel supplier
to determine what precautions, if any, are required to insure
problem-free use of a particular fuel under the temperature conditions
that are possible at a specific mine location.

69. **Are there any engine parts that I will have to replace if I use
    biodiesel?**

As noted above, biodiesel can soften and degrade certain types of
elastomers and rubber compounds over time. Using high percent blends can
have greater impacts on fuel system components such as fuel hoses and
fuel pump seals that contain compounds that are incompatible with B100.
The engine manufacturer should be contacted to determine which, if any
components need to be replaced with their B100 compatible counterparts.
For older engines where specific information on biodiesel compatibility
is not available, replacement of fuel system components with biodiesel
compatible components is recommended.

70. **Will biodiesel clog the fuel filters?**

Standard petroleum diesel, especially #2 diesel, often leaves deposits
in the bottom of fuel tanks and lines. Biodiesel acts as a cleaning
agent, and can dissolve and remove these deposits, which are often
retained on fuel filters, causing filter clogging. As a result, when a
high biodiesel content fuel blend is used following prolonged use of
standard petroleum diesel fuel, fuel filters may need to be changed more
frequently until the entire system is fully cleaned.

71. **Is biodiesel stable?**

Most industry experts recommend that biodiesel fuel should be used
within six months of manufacture to insure that the quality of the fuel
is maintained. Biodiesel, like standard diesel fuel, is subject to
oxidation, microbial growth, and other conditions during long-term
storage. Prior to use, biodiesel fuels stored longer than six months
should be tested for acid number, sediment, and viscosity to insure it
remains within specifications. The acid number goes out of specification
before fuel filters begin to clog or other problems are encountered, so
checking the acid number is a good indicator of fuel stability that can
help prevent fuel stability related problems.

72. **What effect will biodiesel have on engine oil usage?**

Engine oil change intervals may need to be shortened when using high
biodiesel content fuel blends. Due to its slightly higher viscosity and
density, more biodiesel fuel may pass over the piston rings and into the
oil pan. High levels of biodiesel in the engine oil may polymerize over
time, and cause serious engine sludge problems. Shortening engine oil
change intervals will prevent this problem from occurring.

73. **Will the use of biodiesel void my engine warranties?**

Engine manufacturers warrant their engines against defects in materials
and workmanship. The use of a particular fuel should have no effect on
the materials and workmanship warranty. However, manufacturers are
concerned that extensive use of biodiesel will result in increased
numbers of warranty claims for what are actually problems caused by the
fuel. Many manufacturers have issued "position statements" on the use of
biodiesel fuel. More information on biodiesel and engine warranties can
be found at
<http://www.biodiesel.org/resources/fuelfactsheets/standards_and_warranties.shtm>.

**§57.5060(d) RESPIRATORY PROTECTION**

74. **When is respiratory protection allowed?**

When controls do not reduce a miner's DPM exposure to the PEL, controls
are infeasible, or controls do not produce significant reductions in DPM
exposures, controls must be used to reduce the miner's exposure to as
low a level as feasible and must be supplemented with respiratory
protection in accordance with § 57.5005(a), (b), and paragraphs (d)(1)
through (d)(8) of §57.5060 .

Respiratory protection is therefore required if you have been granted an
extension of time in which to comply with the applicable final limit
pursuant to § 57.5060(c). Respiratory protection is also required during
the period between the time a citation for DPM overexposure is issued
and MSHA resampling verifies the effectiveness of engineering and
administrative controls in reducing DPM exposures to or below the final
limit. The mine operator may request MSHA resample once the operator has
implemented routine and usually effective steps to reduce DPM exposure
levels. MSHA will resample at the operator's request to determine
compliance with the PEL and terminate the citation if exposures are
reduced to the PEL.

75. **What are the requirements for using respiratory protection?**

Respiratory protection for compliance would be permitted only after
feasible engineering and administrative controls have been implemented.
When respiratory protection is required for compliance with the final
limit, you must first have a PLHCP make a written medical determination
that the miner can wear a respirator. In addition, you must be in
accordance with a respiratory protection program that meets the
requirements of §57.5060(d). Also, you must use an air-purifying
respirator equipped with filters that meet one of the following
criteria:

-   Certified by NIOSH under 30 C.F.R. Part 11 as high efficiency
    particulate air (HEPA) filter;

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-   Certified by NIOSH under 42 C.F.R. Part 84 as 99.97% efficient; or

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-   Certified by NIOSH for DPM.

NIOSH approved air purifying respirators with R100 or P100 filter or
powered air purifying respirators with HEPA filters will comply with the
MSHA requirements, provided the proper change out frequency is followed.
This would apply to the complete range of approved respirators selected
following the NIOSH Respirator Selection Logic, using the MSHA
permissible exposure limit.

Note that NIOSH issues certificates of approval only for completely
assembled respirators. Respirator filters or filter assemblies are not
certified as separate parts. A respirator may be approved for use with
one or more particulate filters and the entire respirator approved with
a protection level, for example, P100 or N95. A filtering facepiece may
be approved for P100 or other protections.

R-series filters or respirators cannot be used for more than one work
shift. Respirators with N-series filters cannot be used for compliance
with the DPM standard. HEPA filters are not currently tested by NIOSH
for degradation from oil exposures. HEPA filters should be replaced
after a use during a single shift.

76. **Are filtering facepiece respirators available?**

Yes. Air purifying respirators with particulate filters and filtering
facepieces are available in R100 and P100 classes. There are currently
no approved R100 filtering facepiece (disposable particulate
respirators) respirators approved, and the listing of P100 filtering
facepiece respirators can be found on the National Personal Protective
Technology Laboratory web page at:
<http://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/p100list1.html>

Air purifying respirators, including filtering facepieces, may be used
providing the protection factor is adequate for the exposure.

77. **Can I use a loose fitting powered air purifying respirator (PAPR)
    helmet?**

NIOSH-approved powered air purifying helmets with HEPA filters are
acceptable provided the protection factor is adequate for the exposure.
Powered air purifying respirators without a tight fitting facepiece are
typically assigned a protection factor of 25. This means the DPM
concentration in the wearer's breathing zone would be expected to be
1/25 the ambient concentration.

78. **What are the key elements of a DPM respiratory protection
    program?**

 

The key elements of a DPM respiratory protection program are:

a\. a written determination by a PLHCP of the miner's ability to wear a
respirator;

b\. respirator selection that is appropriate for hazards; and

c\. respirator use.

**Employee training:** This training is separate from the DPM training
required by

§ 57.5070. Training must include:

a\. instruction in the nature of the hazard and an appraisal of what may
happen if the respirator is not used;

b\. explanation of feasible engineering and administrative controls and
the efforts made or being made to eliminate the need for respirators;

c\. a discussion of why this is the proper type of respirator for the
particular purpose,

and respirator use, capabilities, and limitations; and

d\. having the respirator fitted, including demonstrations in how the
respirator should be worn, how to adjust it, and how to determine if it
fits properly.

**Respirator cleaning and disinfecting:** The program must include
provision for:

a\. cleaning and disinfecting respirators on a regular basis, or after
each use if they are used by more than one person; and

b\. for disposable respirators, a provision for employees to obtain a
new respirator when theirs becomes unusable, unsanitary, or exhibits
excessive breathing resistance.

**Respirator storage**: The program must include provision for
convenient, clean, and sanitary storage.

**Respirator inspection:** The program must make provision for
respirator inspection before and after each use and during cleaning.
Deficiencies identified must be corrected.

**Surveillance:** The **w**ork area must be periodically checked to
ensure respirator use and

to monitor conditions, employee exposure, and employee stress due to
breathing resistance.

**Program evaluation:** The respiratory protection program must be
evaluated regularly to ensure continued effectiveness.

79. **Now that MSHA requires a medical evaluation of a respirator
    wearer, how long will MSHA give me to establish a respiratory
    protection program for a miner that is overexposed to DPM?**

Although MSHA will make the determination based on site-specific
conditions, in most cases mine operators should not take more than two
weeks to implement the primary components of a respiratory protection
program. These components include a medical evaluation of the miner's
ability to wear a respirator before the miner is required to be fit
tested or to wear a respirator at the mine, selecting an appropriate
respirator, purchasing respirators, providing respiratory training to
miners, and conducting fit testing. Mine operators must make certain
that they also implement the other required components of the
respiratory protection program.

80. **What is a PLHCP?**

MSHA intends that a "physician or other licensed health care
professional (PLHCP)" be a physician, physician's assistant, nurse,
emergency medical technician or other person qualified to provide
medical or occupational health services, as MSHA defined a "health
professional" under the Hazard Communication standards at 30 C.F.R.
47.11. We will accept the license as proof of qualification to perform
the medical evaluation. We specified that the health care worker be
licensed to ensure an acceptable level of competency, but have not
specified which states' licensing to accept.

81. **How long do I have to find a PLHCP and conduct a medical
    evaluation to determine if the miner can wear a respirator, and
    provide the miner with a respirator if the miner is able to wear
    one?**

As soon as feasible.  You should be prepared to immediately implement
the necessary respiratory requirements if controls are not successful in
reducing the miner's exposure to within the PEL.

82. **Do I have to pay for the PLHCP to test the miner to determine if
    the miner can wear a respirator?**

Yes. These tests are to be conducted at no cost to the miner.

83. **What type of test does the PLHCP have to conduct to determine the
    miner's ability to wear a respirator?**

The mine operator must provide a confidential medical evaluation by
PLHCP to determine the miner\'s ability to use a respirator before the
miner is required to be fit tested or to use a respirator at the mine.
The PLHCP may use any medically valid procedure for making this
determination. The final rule does not include a protocol to guide the
PLHCP on how to conduct medical evaluations, but places the
responsibility on the mine operator to provide an appropriate medical
evaluation by a PLHCP to determine the miner\'s ability to use a
respirator before the miner is required to be fit tested or to use a
respirator at the mine. If, however, the PLHCP determines that the miner
cannot wear a negative pressure respirator, the mine operator must make
certain that the PLHCP evaluates the miner's ability to wear a powered
air purifying respirator (PAPR).

84. **What can the miner do if the miner has concerns with or disagrees
    with the PLHCP's medical determination?**

The miner has the right to submit additional evidence of their medical
condition within 30 days of their discussion of the PLHCP's
determination. Afterwards, the mine operator must obtain a written
determination from the PLHCP regarding the miner's ability to wear a
respirator.

85. **How much time do I have to provide the affected miner with a copy
    of the PLHCP's determination as to whether the miner is medically
    able to wear a respirator?**

You must exercise diligence in making certain that the PLHCP provides a
copy of the determination to the miner.

86. **If a miner is required to wear a respirator, does the miner have
    to wear the respirator for the full shift?**

Yes, if the miner continues to work in the affected occupation or area
of the mine for the entire shift.

87. **If the miner is unable to wear a negative pressure respirator, but
    can wear a powered air purifying respirator, do I have to provide
    it?**

You must either provide the powered air purifying respirator or transfer
the miner in accordance with the requirements of this section.

88. **How often do I have to conduct a medical evaluation to determine
    if the miner can wear respirator?**

You must conduct a medical evaluation of a miner's ability to wear a
respirator before a miner is required to be fit tested or required to
wear a respirator in your mine.

89. **When does the miner have to be reevaluated?**

The miner must be reevaluated when you have reason to believe that
conditions have changed which could adversely affect the miner's ability
to wear the respirator.

90. **When and where do I have to transfer a miner?**

You must transfer the miner within 30 days of the final determination of
the PLHCP that the miner is unable to wear a respirator. The miner must
be transferred to an area of the same mine where respiratory protection
is not required.

91. **What if I do not have a position where I can transfer the miner
    that is within the PEL?**

You cannot require a miner to wear a respirator who has been found by
the PLHCP to be unable to wear a respirator or allow the miner to work
in an occupation or area of the mine where the miner's exposure exceeds
the applicable limit.

92. **Do I have to transfer a miner who is medically unable to wear a
    respirator if the miner does not want to transfer?**

Yes, if you have a job to which the miner can be transferred.

93. **What salary do I have to pay a transferred miner?**

You must continue to pay the miner no less compensation than the miner
received for their regular rate of pay in the job classification that
the miner held immediately before the transfer.

94. **If I increase a transferred miner's salary, are the increases
    based on previous job classification or the new job classification
    to which the miner was transferred?**

Wage increases for transferred miners must be based upon the new work
classification.

95. **Do I have to keep any records related to medical evaluation and
    transfer of a miner?**

Yes. You must keep a record of the identification of the PLHCP and the
PLHCP's written determination of the miner's ability to wear a
respirator.

96. **How long do I have to keep the record?**

You must keep the record for the duration of the affected miner's
employment plus six months.

97. **What will MSHA do if I have begun to implement a required
    respiratory protection program, but before it is fully implemented,
    the miner\'s exposure is reduced to the final limit?**

If MSHA sampling results determine that the miner's exposure no longer
exceeds the final limit, the citation will be terminated and that miner
is no longer required to wear a respirator.

98. **If I receive a citation for a violation of the final limit, does
    the miner who was overexposed need to wear a respirator even if that
    miner is working in a different part of the mine?**

No, provided that you did not rotate the miner to reduce the miner's DPM
exposure. A citation for a violation of the final DPM limit will specify
the occupation and the area of the mine affected. You cannot, however,
allow the miner to work without a respirator in an area of the mine
where the miner's exposure exceed the applicable limit.

**[§57.5061, COMPLIANCE DETERMINATIONS]{.underline}**

99. **What sampling and analytical method will MSHA use to determine
    compliance with the final DPM limit?**

MSHA will utilize a standard sampling pump operated at a flow rate of
1.7 liters per minute, 10 mm nylon cyclone, and a specialized submicron
impactor and quartz fiber filter to obtain a personal, full-shift DPM
sample that will be analyzed per NIOSH Method 5040 to determine the
subject miner's average eight hour equivalent full shift exposure to
airborne elemental carbon. MSHA has included on its website the sampling
procedures used by its inspectors.

100. **Are the equipment and supplies that MSHA will use for sampling
     DPM available to the general public?**

Yes. All equipment and supplies, including the specialized DPM sampling
cassettes, are commercially available.

101. **Will MSHA compliance sampling be done only on the basis of
     personal sampling?**

Yes. This will result in a permissible exposure limit (PEL) rather than
a concentration limit.

102. **Whom will MSHA inspectors select for DPM sampling?**

MSHA inspectors will treat DPM similarly to other airborne contaminants
when developing a sampling strategy. Based on observations made in the
mine, evaluation of the mine's ventilation plan, and knowledge of DPM
emission sources, MSHA inspectors will select miners most likely to have
the highest exposure to DPM. This includes miners who work underground
during the entire shift, as well as miners who travel in and out of the
mine during the shift, such as haulage truck drivers who pick up their
load underground and dump it on the surface of the mine. MSHA will
sample as many miners on as many shifts as necessary to fully document
\"worst case\" DPM exposures at a given mine.

103. **How many samples will MSHA take to demonstrate a miner's
     exposure?**

One. To implement § 57.5061(a), MSHA will consider a single personal
sample an adequate basis for a compliance determination. MSHA will issue
a citation as it does for all other contaminant sampling under the metal
and nonmetal standards.

104. **What will MSHA do if I disagree with MSHA's sampling
     determination?**

MSHA would consider information presented by the mine operator in
determining the validity of its sampling results. For example, MSHA
would consider the results of simultaneous sampling conducted by the
mine operator, unusual or abnormal conditions encountered during the
work shift, or other factors that would raise question as to the
validity of the sample. Based on the evaluation, MSHA may decide to
resample.

105. **How will MSHA determine when to issue a citation for a miner's
     overexposure to DPM?**

Upon finding a DPM overexposure, the MSHA District office will review
your efforts towards compliance and determine whether there are feasible
engineering or administrative controls available that you failed to
utilize which can achieve a significant reduction in the miner's DPM
exposure. Such determination will involve having personnel from the
District office contact you to discuss controls utilized and feasibility
concerns unique to your mining operation. It may also involve personnel
from the District office and/or MSHA's Directorate of Technical Support
visiting your operation. If MSHA subsequently identifies feasible
controls that you have not utilized, and which can significantly reduce
the miner's exposure, MSHA will issue a citation. In determining the
gravity of the violation, MSHA will consider the extent and duration of
the overexposure and whether the miner was utilizing respiratory
protection consistent with the requirements of the standard.

106. **How will MSHA determine when to terminate a citation for an
     overexposure to**

**the DPM final limit?**

MSHA will resample to see what progress has been made to reach
compliance levels at the request of an operator who has begun the
abatement process by at least taking routine steps to improve DPM
exposure levels. If an operator has taken additional samples which
indicate possible compliance, MSHA will resample with an additional
single sample and if that sample is in compliance, MSHA will accept that
the condition has been abated. If routine and usually effective steps
such as improved maintenance, administrative controls or the
implementation of a standard DPM exhaust filter program do not achieve
compliance, MSHA, at the operator's request, will assign the mine for a
technical compliance evaluation. That evaluation will include a mine
visit, observation of mining equipment including installed controls and
multiple samples to determine what additional feasible steps will
achieve compliance or achieve substantial reductions toward compliance.
However, if Technical Support has previously evaluated the same piece of
equipment in substantially similar circumstances, it will make an
abbreviated evaluation of the steps needed to reasonably assure
compliance.

##### §57.5065, FUELING PRACTICES

107. **Is low sulfur diesel fuel commercially available?**

Yes. Both number 1 and number 2 diesel fuel meeting the sulfur content
requirement of this rule are commercially available at local gas
stations. Fuel used in over-the-road diesel engines is currently
required by EPA regulations to meet the same 0.05% sulfur content limit
that has been implemented for underground metal and nonmetal mines.

108. **Can low sulfur fuel be differentiated by color (dyed or
     undyed)?**

No. Undyed fuel is for on-highway use and has a low sulfur content. Dyed
fuel can be either low sulfur or high sulfur (greater than 0.05%).

109. **How will I know the sulfur content of the diesel fuel I
     purchase?**

Ask the fuel distributor to give you a specification sheet that
documents the fuel sulfur content. You should keep this sheet with the
DPM records for your mine.

110. **Can underground mines use diesel fuel for on-highway vehicles?**

Yes, all diesel fuel sold in the U.S. for on-highway vehicles is low
sulfur.

111. **Can I use bio-diesel fuel or a blend of bio-diesel and standard
     diesel in my underground equipment?**

Yes, as long as the fuel is low-sulfur.

112. **Why must I use fuel additives that are registered by the EPA?**

Using a fuel additive that has not been thoroughly tested and registered
with the EPA may increase DPM concentrations or expose miners to other
toxic contaminants.

113. **How can I determine whether an additive I wish to use is
     registered with the US EPA ?**

Mine operators should ask the supplier of the additive for evidence that
the additive is registered with the US EPA. Operators can check the
status of any fuel additive directly by referring to the following EPA
Internet website:
<http://www.epa.gov/oms/regs/fuels/additive/web-dies.txt>

Operators can also ask their MSHA inspector or check with MSHA Technical
Support with questions regarding diesel fuel additives.

114. **May I use diesel fuel blended with ethanol?**

Yes. Ethanol has been registered with the US EPA as a diesel fuel
additive. Therefore, ethanol-blended diesel fuel can be used in
underground MNM mines. Mine operators are encouraged to check either the
MSHA or EPA internet web sites to find out whether other blended fuels
have been registered with EPA before using such fuel in their
underground equipment.

**[§57.5066, MAINTENANCE STANDARDS]{.underline}**

115. **Is equipment that is maintained or repaired off-site and then
     brought back to the mine still subject to the maintenance
     requirements of the standard?**

Yes.

116. **In what condition must I maintain my diesel engines?**

MSHA-Approved engines must be maintained in approved condition, emission
related components of non-approved engines must be maintained to
manufacturer specifications, and emission control devices must be
maintained in effective operating condition.

117. **What are the important items to look at on an MSHA-Approved
     engine?**

The important features of an MSHA-Approved engine are the
emission-related components. These components include the piston,
cylinder head, valves, fuel pump and governor, injectors, and
turbocharger (if applicable). Engine settings, such as fuel injection
pump settings, governor settings, and injection timing, can all
adversely affect emissions. Specifications that derate the engine for
altitude must be followed. Locks

and seals must not be removed except by a person qualified to work on
fuel pumps that can reinstall a seal or lock.

118. **What items must be maintained on a diesel engine that is not
     MSHA-Approved?**

Emission related components of engines that are not MSHA-Approved must
be maintained according to manufacturer specifications. These are
basically the same components which MSHA examines for \"approved\"
engines.

119. Will an MSHA inspector require me to tear down an engine to verify
     that all maintenance is performed in strict accordance with the
     standard?

No. However, if it becomes evident during an inspection that engines are
not being maintained to the correct specifications, an inspector may
discuss maintenance procedures with the person performing maintenance
and ask to see the manuals to confirm that the right manuals are being
used.

120. **Why should the miner operating a piece of diesel equipment be
     authorized and**

**required to tag a machine for a suspected emissions related
maintenance problem?**

Diesel engine exhaust emissions, especially carbon monoxide, carbon
dioxide, and DPM, are normally higher when the engine is operating at
full load. Since engines are seldom operated under heavy load in the
shop, a shop mechanic may be unaware of an emissions related engine
fault on a machine, or a problem with an emissions control system that
occurs only when the machine's engine is under full load. Since the
fault may only be seen when the engine is heavily loaded, the machine
operator might be the best person to detect it.

Examples of problems that could be missed by a mechanic are black smoke
coming from the outlet of the exhaust system or leaking around exhaust
joints upstream from a control device. The black smoke may only be
visible when the engine is being worked hard. During light loads or
idle, the black smoke may not be evident due to the excess air in the
combustion system (lower fuel:air ratio).

A system of tagging machines with suspected emission problems does not
depend on potentially unreliable word-of-mouth communication. A visible
tag will also alert other miners who might subsequently use the machine
that a potential emission problem might exist.

121. **What is the meaning of the term "evidence" as it is used in the
     standard relative to the conditions that would constitute
     sufficient cause to tag a piece of diesel equipment having a
     suspected emissions related maintenance problem?**

MSHA has defined "evidence" in the context of this provision to mean
visible smoke or odor that is unusual for that piece of equipment under
normal operating procedures, or obvious or visible defects in the
exhaust emissions control system or in the engine affecting emissions.

122. **Would black smoke being emitted by a machine that is equipped
     with a DPM filter constitute "evidence" of a maintenance-related
     emissions problem that could be tagged by an equipment operator?**

Yes, if visible smoke is unusual for that piece of equipment under
normal operating procedures.

123. **What is the meaning of the term "promptly" as it is used in the
     standard relative to how soon a tagged piece of diesel equipment
     would need to be examined by an authorized person?**

MSHA has defined "promptly" in the context of this provision to mean
before the end of the next shift during which a qualified mechanic is
scheduled to work.

124. **Does a piece of diesel equipment that has been tagged for a
     suspected emissions related maintenance problem have to be
     immediately removed from service?**

No. This requirement is different from MSHA's § 57.14100(c) regulation
that requires self-propelled mobile equipment to be taken out of service
if safety defects make continued operation hazardous. The piece of
equipment must be examined before the end of the next shift during which
a qualified mechanic is scheduled to work, and will need to be removed
from service, at least briefly, for that examination.

125. **What information needs to be included on this DPM emissions
     tag?**

The only requirements are that the tag indicates a possible emissions
problem related to engine maintenance, and that the tag be dated. The
requirement is performance oriented, and any system that conveys the
required information would be acceptable. The specific nature of the
maintenance problem need not be included on the tag. For example, a mine
may choose to use color coding, so that whenever a dated tag of the
specified color is attached to a piece of equipment, it means the
operator believes a possible emissions problem related to engine
maintenance exists on that piece of equipment.

126. **What is the meaning of the term "qualified" as it is used in the
     standard relative to persons authorized by the mine operator to
     maintain diesel equipment?**

The term, "qualified" means the person performing a maintenance task
must have training or experience commensurate with the maintenance task
performed.

127. **Will MSHA check the qualifications of persons performing
     maintenance if there does not appear to be a maintenance problem
     affecting DPM emissions?**

No.

128. **If a piece of diesel-powered equipment requires frequent
     maintenance, will MSHA automatically cite a mine operator for
     having an unqualified person perform maintenance?**

No. The fact that an engine requires frequent maintenance does not
necessarily mean that maintenance was performed by an unqualified
person.

129. **What evidence does an operator have to have to show a person is
     qualified to perform specific maintenance tasks on diesel
     equipment?**

The standard does not specify the type of record that is required. A
record of employment experience or a certificate of training would be
appropriate.

130. **If an independent contractor performs diesel-powered equipment
     maintenance,**

**does the person performing the maintenance need to satisfy the same
qualification requirements as a person employed by the mine operator?**

Yes, if the diesel-powered equipment is used in an underground metal or
nonmetal mine.

131. Do these maintenance standards apply [only]{.underline} to
     MSHA-Approved and engines that meet or exceed the applicable EPA
     particulate matter emission requirements outlined in Table
     57.5067-1)?

     No. These maintenance standards apply to [all]{.underline} diesel
     engines used in the underground areas of metal and nonmetal mines.

     [§57.5067, ENGINES]{.underline}

132. Does my existing fleet of diesel equipment and engines have to meet
     the requirements of the standard?

MSHA conducted an inventory of diesel engines at each underground metal
and nonmetal mine. This inventory was completed in September 2002. The
purpose of this inventory is to enable MSHA inspectors to determine
which engines are newly introduced. Engines introduced after September
2002 must either be MSHA-Approved or comply with the EPA specified
emissions limits contained in Table 57-5067-1.

By introduced, MSHA means any engine added to the underground inventory
of engines of the mine in question. This includes engines in newly
purchased equipment, engines in used equipment brought into the mine,
and replacement engines that have different serial numbers from engines
they are replacing.

MSHA does not consider certain engines that are brought into a mine to
be "introduced" for purposes of enforcing the engine standards. These
exceptions include engines that were previously part of a mine's
inventory, but were removed, rebuilt, and then returned to the same mine
(but only if the engine retains the same serial number), and engines
that are transferred into an underground mine from a different
underground mine operated by the same mine operator.

133. Do the engines in customer vehicles, delivery vehicles, or
     contractor vehicles that enter my mine need to be MSHA-Approved or
     meet or exceed the particulate matter emission requirements
     outlined in Table 57.5067-1?

Delivery and customer vehicles are not covered by the engine or
maintenance requirements of this standard. Independent contractor
vehicles and equipment will be considered on a case-by-case basis.
Independent contractor vehicles and equipment that enter into a mine on
an infrequent, irregular, or nonrecurring basis would not be considered
to be a part of that mine's diesel equipment fleet, and would therefore
not be covered under the engine requirements of this standard.

Independent contractor vehicles that enter a mine on a frequent,
regular, and recurring basis would be considered part of that mine's
diesel equipment fleet, and would therefore be covered under the engine
requirements of this standard.

134. **Do engines in equipment that is operated by a mine development
     contractor for such jobs as shaft sinking or driving a slope, and
     that may be used in a given mine for a year or more, need to be
     MSHA-Approved or meet or exceed the particulate matter emission
     requirements outlined in Table 57.5067-1?**

Such mine development contractors\' equipment is not considered to be
part of a mine\'s inventory of equipment, and therefore, this equipment
does not need to be approved or meet or exceed the particulate matter
emission requirements outlined in Table 57.5067-1. However, these
contractors are considered to be mine operators under the Mine Act, and
they must therefore comply with the other provisions of the rule, such
as using low sulfur diesel fuel, providing DPM training to affected
miners, and conducting DPM exposure monitoring. The contractor\'s
employees are also subject to being sampled by MSHA for compliance with
the DPM final limit.

135. **Does surface equipment that is stored underground (e.g. during
     the winter months) have to be compliant?**

No. The rule applies only to equipment that is used underground and is
therefore part of the underground equipment inventory.

136. **Does surface equipment that is taken into an underground repair
     shop (with a mine ID) have to have a compliant engine?**

No. The rule applies only to equipment that is used underground and is
therefore part of the underground equipment inventory.

137. **How will MSHA determine [when]{.underline} a non-approved,
     non-EPA compliant engine was "introduced" underground for
     determining compliance with §57.5067(a)?**

MSHA conducted a physical inventory of engines at every underground MNM
mine, which was completed in September 2002. Any engine entered onto
this inventory will be considered compliant with § 57.5067(a)(2).
Engines introduced after September 2002 need to be MSHA-Approved or meet
or exceed the particulate matter emission requirements outlined in Table
57.5067-1.

138. **If I transfer an engine from one underground mine to another
     underground mine operated by the same mine operator, does it need
     to be MSHA-Approved or meet the EPA DPM emission specifications
     contained in Table 57.5067-1?**

Section 57.5067(b)(3) allows an engine to be transferred from one
underground mine to another underground mine operated by the same mine
operator without being considered "introduced" into the inventory of
engines for that mine. However, if the engine was introduced into the
first mine after the inventory of engines at that mine, it would have to
be MSHA-Approved or meet the relevant EPA emissions requirements from
Table 57-5067-1 regardless of whether it is operated in that mine or
transferred to another mine operated by the same mine operator.

139. **Can an engine that is not MSHA-Approved and does not meet the
     relevant EPA emissions requirements from Table 57.5067-1 be
     transferred from an underground mine in another country to an
     underground mine in this country if both mines are operated by the
     same mine operator ?**

No. The inventory of engines is completed.

140. Are there exemptions from the engine or maintenance requirements
     for non-production equipment like personnel transports, fuel and
     lube trucks, utility vehicles, and welding trucks?

No. Only ambulances and fire fighting equipment that are used in
accordance with the mine's fire fighting and evacuation plan are
excluded from the engine requirements of §57.5067.

141. **Can I introduce a non-compliant engine (an engine that is not
     MSHA-Approved and does not meet the relevant EPA emissions
     requirements from Table 57-5067-1) if the engine is provided with a
     DPM filter such that the filtered exhaust meets the relevant EPA
     emissions requirements from Table 57.5067-1?**

No. The emission requirements apply to the engine itself, not to the
engine plus devices installed on the equipment on which the engine is
used.

142. **What is an MSHA-Approved engine?**

A diesel engine that is approved under Part 7 or Part 36, Title 30 Code
of Federal Regulations (C.F.R.) is considered an approved engine.

143. **Can an engine certified under MSHA's old approval program, 30
     C.F.R. Part 32 (schedule 24), be introduced into the mine?**

Not on the basis of it being an MSHA-Approved engine. This standard
defines MSHA-Approved as an engine that is approved under Part 7 or Part
36, Title 30 Code of Federal Regulations only. If the engine in question
meets or exceeds the relevant EPA emission requirements listed in Table
57.5067-1, that engine could be introduced into the underground areas of
a mine on that basis, but not on the basis of its being MSHA-Approved.

144. **Where can the list of MSHA-Approved engines be found?**

MSHA lists all approved engines on their homepage at:
<http://www.msha.gov/S&HINFO/DESLREG/1909a.HTM>

145. **How do I know if a given diesel engine is MSHA-Approved?**

     MSHA-Approved engines have an MSHA approval tag attached to the
     engine. The approval tag lists the engine's approval number and
     other pertinent information. The engine manufacturer issues the tag
     when the engine is sold. The engine manufacturer may be contacted
     to provide a tag for an engine as long as the engine is built to
     the MSHA approval specifications for that engine model.

146. **How do I know if a given diesel engine meets the necessary EPA
     DPM** **emission specifications?**

MSHA will accept an engine with an EPA label if the information on the
label matches the requirements in Table 57.5067-1 of §57.5067. If the
engine does not have an EPA label, the engine manufacturer should be
contacted to determine if the engine meets the PM limits specified in
the table.

147. **Is "tailpipe" emission testing required at the mine site?**

     No. The mine operator is not required to conduct "tailpipe"
     emission testing, and MSHA will not conduct such testing to
     determine engine emission compliance. However, a mine operator may
     wish to conduct such testing as a maintenance diagnostic tool, or
     as a way to identify "problem" equipment.

**[§57.5070, MINER TRAINING]{.underline}**

148. **Who needs to receive DPM training?**

All miners "who can reasonably be expected to be exposed to diesel
emissions" in the underground areas of a mine are required to be
trained.

149. **Am I required to give DPM training to miners who work on the
     surface** **at an underground mine?**

No, unless those miners can reasonably be expected to be exposed to
diesel emissions in the underground areas of a mine.

150. **Do surface miners that occasionally drive equipment into an
     underground mine need to receive DPM training?**

No.

151. **Do employees of independent contractors, customer truck drivers,
     and delivery truck drivers need to be trained on DPM?**

Certain independent contractors are mine operators and must be trained
on DPM. Delivery truck drivers and customer truck drivers are not
covered by the training provisions of this standard, but they should be
provided with information on DPM exposure hazards as a part of
hazard-training under MSHA's comprehensive training standard.

152. **When should initial and annual DPM training be provided?**

Initial training should have been provided before July 5, 2001, the
effective date of the training provision. For new miners, such training
must be provided prior to his/her assignment to work that may expose the
miner to DPM. Annual training must be provided within every 12 months
thereafter.

153. **What topics have to be covered in DPM training?**

-   the health risks associated with exposure to diesel particulate
    matter;

-   the methods used in the mine to control diesel particulate matter
    exposures;

-   identification of the personnel responsible for maintaining those
    controls; and,

-   the actions miners must take to ensure the controls operate as
    intended.

154. **Is there a required format for DPM training?**

No. The rule places no constraints on the operator as to how to
accomplish this training. Instruction could take place at safety
meetings before the shift begins. Providing miners with a copy of
MSHA\'s \"Toolbox\" and holding one-on-one discussions that cover the
required topics is another approach that can be used. The Toolbox is
available on MSHA\'s website:

<http://www.msha.gov/S&HINFO/TOOLBOX/TBCOVER.HTM>

155. **Can DPM training be combined with Part 48 training?**

Yes, but it doesn\'t have to be.

156. **If DPM training is combined with Part 48 training, do I need to
     submit a Part 48 training plan modification to the District
     Manager?**

Yes.

157. **Do I need to retain a record of DPM training?**

Yes, for 1 year after completion of training.

158. **If I provided initial DPM training for a new miner on September
     1, 2004, what is the latest date that miner may receive annual DPM
     training?**

September 30, 2005.

159. **Must training be given by MSHA-Approved instructors?**

No. The rule does not specify instructor qualifications. However, if DPM
training is combined into Part 48 training, the Part 48 regulations
regarding MSHA-Approved instructors would apply.

160. **Where can I get assistance with DPM training?**

These Questions/Answers can be used in miner training, as well as the
1997 MSHA publication, "Practical Ways to Reduce Exposure to Diesel
Exhaust in Mining -- A Toolbox." The Toolbox is available on MSHA\'s
website:
[http://www.msha.gov/S&HINFO/TOOLBOX/TBCOVER.HTM](http://www.msha.gov/S&HINFO/TOOLBOX/TBCOVER.HTM )

Assistance is also available through MSHA's Educational Field Services.

**[§57.5071, EXPOSURE MONITORING]{.underline}**

161. **What is the purpose of exposure monitoring for DPM?**

Mine operators are required to conduct exposure monitoring for DPM for
several reasons. Exposure monitoring enables the mine operator to
determine whether DPM exposure levels are in compliance with the final
DPM limit on a continuing basis. The mine operator can use the
information gathered through monitoring to determine whether corrective
action is necessary to achieve or maintain compliance and to assess the
ongoing effectiveness of DPM control measures. This requirement also
ensures special attention will be focused on conditions most likely to
result in overexposure to DPM.

162. **How often do I need to conduct monitoring for DPM exposures?**

A specific DPM monitoring schedule is not included in the standard. Mine
operators are required to monitor as often as necessary to verify
continuing compliance. Once compliance has been verified, MSHA would not
anticipate that extensive additional monitoring would be required.
However, if conditions affecting DPM emissions or in-mine DPM
concentrations change significantly, such as by the addition of new
equipment or changes in the ventilation system, the mine operator would
be expected to verify that these changes have not resulted in any DPM
overexposures. Generally, once monitoring has verified that these
changes have not caused the exposure limit to be exceeded, the mine
operator could likely return to the practice of occasional spot
checking.

163. **Who can observe operator monitoring, and does MSHA restrict the
     number of persons observing monitoring?**

The opportunity to observe monitoring extends to both miners and their
representatives. MSHA does not intend to limit the number of miners who
may observe monitoring.

164. **Will I be paid for observing the operator's monitoring?**

No. Section 103(f) does not authorize "walk around pay" for time spent
by a representative of miners observing a mine operator's monitoring
program.

165. **Do I need to monitor DPM exposures using the same method MSHA
     will use for compliance determinations (respirable dust sampler
     equipped with a submicron impactor, analyzed for elemental carbon
     using the method described in NIOSH Analytical Method 5040)?**

No. This requirement is performance oriented, and any method that would
indicate whether compliance with the DPM limit is being maintained on an
on-going basis would be acceptable.

166. **What other methods are available for DPM monitoring? What are
     their advantages and disadvantages?**

Generally, the advantages of using a method other than that specified
for compliance determinations in the standard are simplicity and cost.
Three alternatives to MSHA's compliance sampling and analytic method are
summarized below:

Sampling can be conducted as specified for MSHA compliance, but without
the cyclone or specialized submicron impactor. Analytical results may be
influenced by mineral dust interference, and would probably indicate
higher DPM levels than would have been the case using the cyclone and
impactor.

Sampling can be conducted as specified for MSHA compliance, but sample
analysis can be gravimetric (by weight) instead of employing the
thermo-optical method of analysis specified in NIOSH Method 5040. Since
the impactor removes all particulates greater than 0.9 µm in size, all
non-DPM particulates are removed before reaching the filter. A
disadvantage of the gravimetric approach is that it is less accurate at
low DPM concentrations than thermo-optical analysis.

Another common DPM sampling and analytic method is the RCD method. RCD
refers to [r]{.underline}espirable [c]{.underline}ombustible
[d]{.underline}ust. In this method, a respirable dust sample is
collected, weighed, heated to 400° C in an oven to burn off all
carbonaceous material (including DPM), and then weighed again. The
difference in weight pre- and post-heating represents the DPM collected
on the filter. Since this method relies on weighing for analysis, its
accuracy is limited at low DPM concentrations.

167. **How do I convert a time weighted average concentration to a shift
     weighted average concentration for comparison to MSHA compliance
     sampling results?**

When DPM concentrations have been computed using the actual sampling
times, the result is a time weighted average (TWA) concentration. This
is the form that commercial industrial hygiene laboratories usually
report analytical results. To convert a TWA concentration to a shift
weighted average (SWA) concentration, the TWA is multiplied by the ratio
of actual shift length (in minutes) to the 8-hour shift equivalent (480
minutes) using the following equation:

[actual shift length (in minutes)]{.underline}

SWA = TWA of DPM as measured x 480 minutes

168. **Would area sampling be considered an acceptable sampling strategy
     for compliance with the exposure monitoring provisions ?**

Yes, provided the area sampling provides reasonable assurance that no
miner's personal exposure to DPM exceeds the limit.

169. **Will MSHA issue a citation for a miner's overexposure based on
     the mine operator's sampling results?**

No. MSHA's citations for a miner's overexposure to DPM will be based on
an MSHA sampling result. MSHA may use an operator's sampling results as
the basis for other enforcement action. For example, if an operator's
sampling results indicate that a miner was overexposed but the operator
failed to take corrective action by the next work shift, as required by
§57.5071(c), MSHA would issue a citation for violating that standard.

170. **Are there any commercial analytic laboratories that are equipped
     to analyze DPM samples for elemental carbon in accordance with the
     method described in NIOSH Method 5040?**

Yes. At the time this Compliance Guide was written, MSHA was aware of at
least 6 commercial industrial hygiene laboratories that were equipped to
analyze DPM samples per the NIOSH Method 5040. MSHA's Internet web site
provides a list of commercial laboratories that provide analytical
services per NIOSH Method 5040.

171. **What do I need to do if my exposure monitoring results indicate
     that any of my miner's exposure to DPM exceeds the DPM limit?**

If a mine operator's sample results indicate that the DPM limit has been
exceeded, the operator must promptly post a notice indicating the
corrective action to be taken, the corrective action must be initiated
by the next shift, and the corrective action must be promptly completed.

172. **Do I have to post the results of each sampled miner even if there
     is no overexposure?**

Yes. MSHA intends for mine operators to post monitoring results for all
affected miners, including those results from MSHA sampling.

173. **What is meant by the term "promptly" that is used twice in
     §57.5071(c)?**

Promptly means without delay. In the context of posting notice, promptly
means the mine operator must post notice as soon as it has been decided
what corrective action will be taken. Since the corrective action must
be initiated by the next work shift, the time frame for posting notice
is quite short.

In the context of completing the corrective action, promptly means that
fully implementing the corrective action cannot be delayed. The time
frame for completing the corrective action depends on the nature of the
action being taken. For example, retraining a miner on proper work
practices to reduce DPM emissions may not take as long as retrofitting a
new, low emission engine on a piece of equipment. Whatever the action
taken, it must not be unduly delayed.

**[§57.5075, DIESEL PARTICULATE RECORDS]{.underline}**

174. **What records do I need to keep, and for how long?**

+-----------------------------------+------------+---------------------+
| **Record**                        | **Section  | **Retention time**  |
|                                   | r          |                     |
|                                   | eference** |                     |
+-----------------------------------+------------+---------------------+
| 1\. Approved application for      | 57.5060(c) | Duration of         |
| extension of                      |            | extension           |
|                                   |            |                     |
| time to comply with exposure      |            |                     |
| limits.                           |            |                     |
+-----------------------------------+------------+---------------------+
| 2\. Identity of PLHCP and most    | 57.5060(d) | Duration of miner's |
| recent                            |            | employment plus 6   |
|                                   |            | months.             |
| written determination of miner's  |            |                     |
| ability                           |            |                     |
|                                   |            |                     |
| to wear a respirator.             |            |                     |
+-----------------------------------+------------+---------------------+
| 3\. Purchase records noting       | 57.5065(a) | 1 year beyond date  |
| sulfur content of diesel fuel     |            | of                  |
|                                   |            |                     |
|                                   |            | purchase            |
+-----------------------------------+------------+---------------------+
| 4\. Maintenance log               | 57.5066(b) | 1 year after date   |
|                                   |            | any                 |
|                                   |            |                     |
|                                   |            | equipment is tagged |
+-----------------------------------+------------+---------------------+
| 5\. Evidence of competence to     | 57.5066(c) | 1 year after date   |
| perform maintenance               |            | maintenance         |
|                                   |            | performed           |
+-----------------------------------+------------+---------------------+
| 6\. Annual training provided to   | 57.5070(b) | 1 year beyond date  |
| potentially exposed miners        |            | training completed  |
+-----------------------------------+------------+---------------------+
| 7\. Record of corrective action   | 57.5071(c) | Until the           |
|                                   |            | corrective action   |
|                                   |            | is completed        |
+-----------------------------------+------------+---------------------+
| 8\. Sampling method used to       | 57.5071(d) | 5 years from sample |
| effectively evaluate a miner's    |            | date                |
| personal exposure, and sample     |            |                     |
| results                           |            |                     |
+-----------------------------------+------------+---------------------+

175. **Do the records have to be kept at the mine?**

Records do not have to be kept at the mine site, but if they are
maintained off-site, they need to be immediately accessible at the mine
site by electronic transmission.

176. **Once MSHA requests DPM records, how much time will I be given to
     provide**

**them?**

MSHA expects mine operators to be diligent in providing required
records. Records are important in guiding inspection decisions. There
must be no unnecessary delay in providing them. If the records are
maintained at an offsite location, whether in hard copy or electronic
format, they must be accessible from the mine site by electronic file
transfer, e-mail, fax, or similar means.

177. **How do I obtain compliance assistance from MSHA on this rule,
     including DPM control methods and sampling?**

Mine operators, miners, miner's representatives, and independent
contractors who work on mine property can check MSHA's Internet web site
([www.msha.gov](http://www.msha.gov/)) for a variety of compliance
assistance materials such as a list of approved engines, a list of
particulate filters for installation on diesel engines (with filter
efficiencies), Program Information Bulletins and Policy Letters, and
information on DPM sample cassettes with integral submicron impactor.
Other information that is available specifically for this standard
includes the "Estimator" (a computer spreadsheet program that permits
the user to estimate the effectiveness of proposed, user specified DPM
controls). MSHA has developed a trouble-shooting guide, a decision tree
to aid in the selection of filters, examples of written compliance
strategies, and other aids. MSHA's Internet site also has links to other
sites containing useful information, such as those of NIOSH and EPA.

Requests for compliance assistance on this or any MSHA standard may also
be made directly to any MSHA Metal and Nonmetal Inspector, Field Office,
District Office,

National office, MSHA Educational Field Services, or MSHA's Directorate
of Technical Support.