MSHA Proposed Rules

Respirable Coal Mine Dust: Continuous Personal Dust Monitor (CPDM)   [10/14/2009]
FR Doc E9-24665
[Federal Register: October 14, 2009 (Volume 74, Number 197)]
[Proposed Rules]               
[Page 52708-52712]
From the Federal Register Online via GPO Access []



Mine Safety and Health Administration

30 CFR Parts 70, 71 and 90

RIN 1219-AB48

Respirable Coal Mine Dust: Continuous Personal Dust Monitor 

AGENCY: Mine Safety and Health Administration (MSHA), Labor.

ACTION: Request for information.


SUMMARY: This document requests information related to the use of the

[[Page 52709]]

Continuous Personal Dust Monitor (CPDM) as a sampling device to measure 
a miner's exposure to respirable coal mine dust.
    In September 2006, the National Institute for Occupational Safety 
and Health (NIOSH) published the results of a collaborative study 
designed to verify the performance of the pre-commercial CPDM in 
laboratory and underground coal mine environments. According to the 
NIOSH Report of Investigations 9669, ``Laboratory and Field Performance 
of a Continuously Measuring Personal Respirable Dust Monitor,'' the 
CPDM is a new monitoring device that is accurate, precise, and durable 
in providing continuous exposure information previously not available 
to coal miners and coal mine operators.
    MSHA is requesting information regarding whether the use of the 
CPDM would lead to more effective monitoring and control miners' 
exposure to respirable coal mine dust during a working shift. Responses 
to this request for information will assist MSHA in determining: How to 
best use the monitoring capability of the CPDM to improve miner health 
protection from disabling occupational lung disease; the feasibility of 
more effective exposure monitoring given the availability of CPDM; and 
what regulatory and non-regulatory actions to consider regarding the 
use of the CPDM in coal mines.

DATES: All comments must be received by midnight Eastern Standard Time 
on December 14, 2009.

ADDRESSES: Comments must be clearly identified with ``RIN 1219-AB48'' 
and may be sent by any of the following methods:
    (1) Federal e-Rulemaking Portal: Follow 
the instructions for submitting comments.
    (2) Electronic mail: Include ``RIN 1219-
AB48'' in the subject line of the message.
    (3) Facsimile: 202-693-9441. Include ``RIN 1219-AB48'' in the 
subject line of the message.
    (4) Regular Mail: MSHA, Office of Standards, Regulations, and 
Variances, 1100 Wilson Boulevard, Room 2350, Arlington, Virginia 22209-
    (5) Hand Delivery or Courier: MSHA, Office of Standards, 
Regulations, and Variances, 1100 Wilson Boulevard, Room 2350, 
Arlington, Virginia. Sign in at the receptionist's desk on the 21st 
    Comments can be accessed electronically at 
under the Rules and Regs link. MSHA will post all comments on the 
Internet without change, including any personal information provided. 
Comments may also be reviewed at the Office of Standards, Regulations, 
and Variances, 1100 Wilson Boulevard, Room 2350, Arlington, Virginia. 
Sign in at the receptionist's desk on the 21st floor.
    MSHA maintains a list that enables subscribers to receive e-mail 
notification when rulemaking documents are published in the Federal 
Register. To subscribe, go to

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director, Office 
of Standards, Regulations, and Variances, MSHA, 1100 Wilson Boulevard, 
Room 2350, Arlington, Virginia 22209-3939. Ms. Silvey can be reached at (Internet E-mail), (202) 693-9440 (voice), or 
(202) 693-9441 (facsimile).


I. Background

A. Continuous Personal Dust Monitor (CPDM)

    For over two decades, researchers and MSHA have attempted to 
identify technology that would provide real-time information on 
respirable coal mine dust (respirable dust) levels to which miners are 
exposed. Such information would enable a mine operator to be more 
proactive in determining when to take corrective measures to avoid 
miners' exposure to excessive levels of respirable dust. The CPDM 
provides a direct measurement of respirable dust in the mine atmosphere 
on a real-time basis, unlike the existing sampling system used since 
1970. As such, MSHA believes that corrective action based on CPDM 
monitoring results can be part of a comprehensive health protection 
strategy that reduces miners' exposure to excessive levels of 
respirable dust; thereby reducing occupational lung disease among coal 
miners, including coal workers' pneumoconiosis (CWP) or ``black lung'' 

B. Description of the Continuous Personal Dust Monitor (CPDM)

    The CPDM is a respirable dust sampler and gravimetric analysis 
device that is incorporated into the miner's cap lamp battery case as a 
single package located on the belt. The device represents the first 
major advance in dust sampling technology in more than 30 years. The 
new cap lamp battery case contains all the components, including two 
separate batteries, to enable the dust monitor and cap lamp to operate 
independently. Air from a miner's work environment enters the sampling 
device through an inlet located adjacent to the lens of the cap light 
on the miner's hard hat and flows via a flexible tube that runs 
parallel to the lamp cord to the belt-mounted device. Before entering 
the CPDM, the air stream is first coursed through a Higgins-Dewell (HD) 
cyclone to separate the coarse or non-respirable dust, so that only 
airborne particles that could penetrate to the lung will enter the 
device. From there, the air stream flows through: (1) A heater to 
remove excess moisture; (2) a 14-mm diameter glass fiber filter where 
respirable-size dust particles are collected; (3) a flow rate sensor; 
and, (4) a computer-controlled pump.
    An exchangeable filter cartridge is mounted on an inertial mass 
sensor called the Tapered Element Oscillating Microbalance 
(TEOM[supreg] system). The TEOM system is made of a hollow tapered tube 
called the tapered element, which is clamped at the base and free to 
oscillate at its narrow or free end on which the collection filter is 
mounted. Electronics positioned around the sensor cause the tube to 
oscillate at its natural frequency. When dust particles are deposited 
on the collection filter, the mass of the collection filter increases, 
causing the natural oscillating frequency of the tapered element to 
decrease. Because of the direct relationship between mass and 
oscillating frequency, the amount of respirable dust deposited on the 
filter can be determined by measuring the frequency change. The 
concentration of respirable dust in the mine atmosphere is then 
determined by the on-board computer by dividing the mass of dust 
collected by the volume of mine air that passed through the system 
during the time period sampled.
    To accommodate shifts greater than 8 hours in duration, the CPDM is 
designed to operate for 12 hours. The display on the device 
continuously shows: (1) The respirable dust concentration calculated at 
distinct 30-minute intervals; (2) the average respirable dust exposure 
from the beginning of the shift; and, (3) the percent of exposure 
limit. Through the display, both the mine operator and miners wearing 
the device have the ability for the first time to gauge respirable dust 
exposures, as well as the effectiveness of corrective actions taken by 
authorized personnel to reduce a miner's exposure. The CPDM is capable 
of being used in a shift mode, in which the device is programmed by 
authorized personnel to operate for specific shift lengths (e.g., 8, 
10, 12 hours) to monitor a miner's exposure, or in an engineering mode 
for shorter-term evaluations. If the monitor is operated in an 
engineering mode, authorized personnel would program sampling periods 
within the

[[Page 52710]]

shift to record respirable dust levels during specific mining cycles or 
at specific dust-generation sources in the mine. The display has 
various screens that show the: (1) Time of day; (2) elapsed time since 
beginning of the shift; (3) total amount of respirable dust accumulated 
on the filter since the start of sampling which is stored in an 
internal memory for analysis; (4) dust concentrations; (5) operational 
parameters including flow rate, filter pressure, temperature, etc.; 
and, (6) a bar graph of the average respirable dust concentration 
during the entire sampling period. Each bar represents the average 
concentration value for each previous 30-minute interval, with a new 
bar added to the graph every 30 minutes. This, along with other 
information, is stored in the CPDM and can be accessed with a personal 
computer at the end of the shift for analysis and recordkeeping.
    The CPDM is neither capable of directly measuring the quartz 
content of the collected sample; nor is the exchangeable filter 
cartridge, as it is currently designed, suitable to permit the 
deposited dust to be analyzed for quartz. Therefore, regardless of the 
regulatory or non-regulatory actions considered regarding the use of 
the CPDM to monitor respirable coal mine dust, the sampling equipment 
approved under existing standards will continue to be used to collect 
separate respirable dust samples for quartz analysis.

C. Collaborative Study Results

    All phases of the NIOSH collaborative study have been successfully 
completed. These included: (1) Planned 10 underground in-mine tests; 
(2) subsequent extended testing undertaken by and at the request of 
several mine operators at four additional underground coal mines; (3) 
special area sampling at 180 randomly selected mechanized mining units 
to determine the equivalency of the pre-commercial CPDM to the Mining 
Research Establishment (MRE) instrument and the International Standards 
Organization (ISO) definition of respirable dust; and, (4) laboratory 
pre- and post-accuracy testing.
    On August 14, 2006, NIOSH posted the results of the collaborative 
study on its Web site, concluding that the new monitoring device was 
found to be accurate, precise, and durable under harsh mining 
conditions in providing real-time continuous information on respirable 
dust exposure. These findings and other observations are explained in 
more detail in the NIOSH Report of Investigations 9669, ``Laboratory 
and Field Performance of a Continuously Measuring Personal Respirable 
Dust Monitor,'' DHHS (NIOSH) Publication No. 2006-145. The report, 
which was published in September 2006, is posted on NIOSH's Web site at

II. Rulemaking History

    On July 7, 2000, the Secretary of Labor and the Secretary of Health 
and Human Services jointly published the proposed rule, ``Determination 
of Concentration of Respirable Coal Mine Dust,'' (Single Sample; 65 FR 
42068), which would enable MSHA to more effectively identify and 
address overexposures to respirable coal mine dust. Under the proposal, 
MSHA would determine miners' exposure to coal mine dust based on the 
results of a single-shift sample, rather than on the average of 
multiple samples, as has been the Agency's longstanding practice.
    On July 7, 2000, MSHA also published a proposed rule on 
``Verification of Underground Coal Mine Operators' Dust Control Plans 
and Compliance Sampling for Respirable Dust'' (Plan Verification; 65 FR 
42122). Under the proposal, each operator of an underground coal mine 
would be required to verify and periodically monitor, through sampling, 
the effectiveness of dust controls for each mechanized mining unit 
specified in the mine's approved ventilation plan.
    On March 6, 2003, in response to comments, MSHA reproposed both the 
Plan Verification rule (68 FR 10784), and Single Sample rule (68 FR 
10940). The proposed rule on Plan Verification would integrate the use 
of CPDMs, with real-time monitoring, as part of an effective dust 
control program once the technology was verified as reliable under 
mining conditions and commercially available.
    Public hearings on the Single Sample and Plan Verification proposed 
rules were held in May 2003, and the comment period, originally 
scheduled to close on June 4, 2003, was extended until July 3, 2003. On 
July 3, 2003, MSHA extended the comment period on the Plan Verification 
proposal until further notice (68 FR 39881). In addition, on August 12, 
2003, MSHA and NIOSH reopened the rulemaking record and extended the 
comment period on the Single Sample proposal until further notice (68 
FR 47886).
    In August 2003, MSHA convened a meeting with representatives from 
NIOSH, the developer of the CPDM, and stakeholders representing the 
mining industry and labor. The purpose of the meeting was to solicit 
the parties' participation in a collaborative study on performance 
verification testing of 25 new pre-commercial CPDMs purchased by MSHA 
and NIOSH. The parties agreed to participate in this study to evaluate 
all aspects of the long-term performance of the CPDM in a variety of 
underground coal mine environments.
    Existing 30 CFR part 74, specifies requirements for approval of 
coal mine dust personal sampler units designed to determine the 
concentrations of respirable dust in coal mine atmospheres; procedures 
for applying such approval; test procedures; and labeling. On January 
16, 2009, MSHA published a proposed rule in the Federal Register on 
Coal Mine Dust Personal Monitors (74 FR 2915). The proposed rule would 
revise requirements that MSHA and NIOSH apply to approve sampling 
devices that monitor miner exposure to respirable dust. The proposal 
would establish criteria for approval of the CPDM, which would be worn 
by the miner and would report exposure to dust levels continuously 
during the shift. In addition, the proposal would update application 
requirements for the existing ``coal mine dust personal sampler unit'' 
to reflect improvements in this sampler over the past 15 years. This 
document requests information regarding potential CPDM use for more 
effective monitoring and control of respirable coal mine dust.

III. Key Issues on Which Comment Is Requested

    A number of important issues must be addressed by MSHA to develop 
an effective and comprehensive monitoring strategy incorporating 
continuous direct-reading exposure measurement technology for use in 
the Nation's coal mines. As part of this strategy, the Agency is 
seeking comments from the mining community on how best to use the 
unique monitoring capabilities offered by the CPDM in its overall 
strategy to further improve miner health protection from disabling 
occupational lung disease.
    MSHA is especially interested in comments addressing the issues 
below; however, comments on any relevant issues are welcome. Comments 
should be specific and include alternatives, rationale, health benefits 
to miners (e.g., lives saved, illnesses averted), technological and 
economic feasibility, impact on small mines, and supporting data.

A. CPDM Application Strategies

    The existing system of monitoring concentrations of respirable dust 
in the mine atmosphere where miners work or travel relies on periodic 

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and area or environmental sampling. Corrective actions are required 
when sampling results indicate noncompliance with the applicable dust 
standard. Because all dust samples taken for compliance purposes must 
be transmitted to MSHA for processing, the results are not known for 
days after sampling. Consequently, if results require the operator to 
take corrective action to reduce airborne dust levels, those efforts 
would only affect exposures on subsequent work shifts; this may be some 
time period after sampling. Continuous exposure monitoring, on the 
other hand, would provide mine operators with information about the 
actual dust levels in the workplace on a real-time basis. This would 
permit mine management to be proactive in taking corrective action 
during the shift to prevent possible overexposures by optimizing mining 
practices and implementing appropriate measures to correct problems as 
they arise. However, successful use of CPDMs for exposure assessment 
and control will depend on the proper application of the device's 
capability to supply timely information on respirable dust 
concentrations during a working shift, the proper interpretation of the 
information provided, and timely intervention to prevent overexposing 
miners. In this context, MSHA requests comment on the following related 
to the application of the CPDM:
    1. Please address conditions and circumstances under which CPDMs 
should be proposed for use in underground coal mines. In your response, 
include factors such as mine size, compliance history, type of mining, 
presence of quartz, and designated occupation. In addition, please 
address whether the CPDM could be integrated into the existing 
compliance strategy, and, if so, how. Please be specific in your 
response, and address any technological and economic feasibility issues 
associated with using CPDMs.
    2. Please address the advantages and disadvantages of the existing 
compliance strategy, which relies on a combination of occupational and 
area sampling, versus a personal exposure monitoring strategy only. 
Please be specific in your response, noting the safety and health 
benefits of each strategy.
    3. If CPDMs were to be required, how should a compliance strategy 
based on CPDMs be structured? Please be specific as to miners and 
occupations covered and include the rationale for your response. 
Include suggestions for the role of the mine operator, miner, miners' 
representatives, and MSHA under such a strategy.
    4. How would the use of CPDMs impact the frequency of sampling? 
Please be specific and address how the concentration and exposure 
levels impact the frequency of sampling.
    5. What examinations should be performed to assure the validity of 
exposure measurements, and how frequently should these examinations be 
    6. Since the current exposure limits were developed from 8-hour 
shift exposure measurements, how should the miner's end-of-shift 
exposure be reported when the work shift is longer than 8 hours?
    7. Since the CPDM cannot be used to monitor for quartz, how should 
the applicable dust standard, including reduced standards established 
when the quartz content of the respirable dust exceeds 5 percent, be 
addressed when using a CPDM?
    8. Please address the use of CPDMs for sampling in outby areas, 
including specific areas, occupations, and frequency of sampling.
    9. Please address the use of engineering and administrative 
controls including how such controls should be applied to the CPDM's 
real-time exposure readings.
    10. What action should be taken by the mine operator when a miner's 
exposure during a working shift reaches the dust standard limit?
    11. Please address the use of CPDMs at surface mines, including 
sampling of areas, occupations and miners.

B. Dust Control Plan Requirements

    Providing and maintaining a work environment free of excessive 
levels of respirable dust is essential for long-term health protection. 
Monitoring the work environment provides an indication of the 
effectiveness of existing dust controls; however, monitoring alone does 
not control concentrations of respirable dust in the mine atmosphere. 
Accordingly, consistent with MSHA's regulatory strategy, engineering or 
environmental controls are the principal methods that have been relied 
on over the past 35 years to prevent or minimize miners' exposures to 
both primary and secondary sources of respirable dust in the workplace. 
These controls are required in an operator's approved mine ventilation 
plan to provide assurance that miners are not being exposed to 
excessive dust levels. Since the CPDM provides real-time information on 
concentration levels, MSHA is exploring alternatives to limiting 
miners' exposures. MSHA is therefore requesting comments on the 
following dust control plan issues:
    1. Please address the advantages and disadvantages of using 
engineering controls to maintain the mine atmosphere in the area where 
miners work or travel. Please be specific in your response and include 
the technological and economic feasibility of such controls. In 
addition, please address the advantages and disadvantages of using 
administrative controls as part of an effective exposure control 
    2. If CPDMs are used, please address the information that would 
need to be included in the dust control portion of the mine ventilation 
plan, including information related to addressing silica.

C. Recordkeeping

    To promote miners' awareness of the air quality in the work 
environment and the integrity of the sampling process, existing 
regulations require mine operators to send all collected samples to 
MSHA for processing within 24 hours after the end of the sampling 
shift. Once processed, the operator is provided with a respirable dust 
sample data report, which contains the results of every sample 
submitted. With few exceptions, the operator must post this report on 
the mine bulletin board for a period of 31 days to provide miners 
access to current information on respirable dust conditions in the 
mine. The results of all samples taken by mine operators and MSHA 
inspectors are maintained by MSHA in a database and retained 
permanently. With exposure information available at the completion of 
the work shift when a CPDM is used, existing recordkeeping requirements 
and responsibilities would need to be addressed. MSHA requests comment 
on how recordkeeping requirements based on the use of CPDMs should be 
structured. Please be specific in your response.
    1. Who should be responsible for maintaining the CPDM data files 
and why? How long should exposure records be maintained? How should 
information be used?
    2. How should the data from operator monitoring using the CPDM be 
transmitted to MSHA? What data should be transmitted? How often should 
the data be transmitted (e.g., daily, weekly, or some other frequency)? 
What steps should be taken to ensure the integrity of the data 
transmitted to MSHA?
    3. Under current regulations, mine operators, with few exceptions, 
post the monitoring results on the mine bulletin board for a period of 
31 days. How practicable would it be for operators to continue this 
practice if the monitoring is conducted with the CPDM, which

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results in the collection of significantly more data than with the 
current MRE instrument? Would it be appropriate for operators to only 
provide miners with a portion of the data captured by the CPDM or to 
post the data for a period less than 31 days? Please be specific with 
your response, including your rationale.

D. Education and Training

    It is vital that persons designated by the mine operator to perform 
dust sampling functions and miners be properly educated and trained to 
assure the integrity and credibility of the sampling process. To be 
effective, these persons must be fully cognizant of the nature of the 
health hazards in the working environment and possess a level of 
competence in the proper use, operation and maintenance of sampling 
equipment, and an awareness of the limitations of available protective 
measures. The required level of competence would be dictated by the 
complexity inherent in the operation of the particular CPDM and the 
degree to which oversight of sampling integrity is to be assumed by 
mine operators using the CPDMs. MSHA requests comments on suggested 
elements for a training program on using and maintaining a CPDM. Please 
be specific in your response, addressing the quality, quantity, and 
types of training, and the qualifications and certifications that 
should be required.
    1. What training should miners receive if required to wear a CPDM? 
What type of training would be necessary to assure that the miner 
understands how the device works, what information it provides, and how 
that information should be used to reduce miners' exposure to 
respirable dust? How often should miners be required to receive this 
    2. What qualifications should be required before an individual is 
permitted to operate and maintain a CPDM? How should an individual be 
required to demonstrate proficiency before being permitted to operate 
and maintain a CPDM?
    3. Which mine personnel should oversee CPDM usage, download 
exposure information, and interpret data? What type of qualifications/
certifications should these personnel be required to have?

E. Benefits and Costs

    Because of the changing mining environment, more timely feedback on 
current respirable dust conditions in the workplace should 
significantly enhance miner health protection. Benefits would include 
the ability to immediately identify hazardous dust conditions that 
cause debilitating and potentially fatal coal workers' pneumoconiosis 
or ``black lung'' disease, and to reduce or eliminate the risk of 
overexposure and the potential for illness and premature death, thereby 
avoiding the attendant costs to employers, miners and their families, 
and society.
    MSHA requests comment on the following questions concerning the 
benefits and costs of the CPDM:
    1. What would be the benefits of using CPDMs in a comprehensive and 
effective compliance strategy? Note that benefits might differ 
depending upon which compliance strategy is selected.
    2. What costs would be associated with using CPDMs? Please be 
specific as to every component, such as, initial outlay, maintenance, 
and training.
    3. What would be the advantages, disadvantages, and relative costs 
of different methods of using CPDMs?
    4. Would the use of CPDMs affect small mines differently than large 
mines, and if so, how?
    5. What incentives, if any, should MSHA consider to promote 
effective use of CPDMs in coal mines?
    6. What actions, if any, should MSHA take to encourage coal mining 
industry acceptance of the CPDM technology, stimulate economic market 
forces for more competitive pricing of CPDM devices, and promote 
innovation in respirable dust monitoring technology?

    Dated: October 7, 2009.
Gregory R. Wagner,
Deputy Assistant Secretary for Policy, Mine Safety and Health 
[FR Doc. E9-24665 Filed 10-13-09; 8:45 am]