[Federal Register: October 14, 2009 (Volume 74, Number 197)]
DEPARTMENT OF LABOR
Mine Safety and Health Administration
30 CFR Parts 70, 71 and 90
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
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: http://www.regulations.gov. Follow
the instructions for submitting comments.
(2) Electronic mail: zzMSHAemail@example.com. 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 http://www.msha.gov
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 http://www.msha.gov/subscriptions/subscribe.aspx.
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
Silvey.Patricia@dol.gov (Internet E-mail), (202) 693-9440 (voice), or
(202) 693-9441 (facsimile).
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 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
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
occupational 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.
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 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,
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,
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]
BILLING CODE 4510-43-P