9
for direct-on-filter measurement by FTIR and Raman
spectrometers and the development of an end-of-shift RCS
quantification method by Raman spectroscopy is also being
performed.
PDM3700-compatible Filter Module Usable with Portable/
Field-Deployable Silica Monitoring Instruments -Thermo
Environmental Instruments
The CPDM is required for sampling at coal mines in the
U.S. by MSHA. The CPDM provides near real-time respi-
rable dust concentrations (concentrations averaged over
a 30-minute time period) and the dust being sampled is
collected on a filter which is ultimately discarded. Thermo
Fisher Scientific is developing a filter module (filter mate-
rial, a holder, and possibly additional supporting elements
and an adaptor) for the CPDM that can be used with a
portable FTIR, QCL, or other infrared (IR) absorption
method that is used to determine the silica content of the
dust being sampled. A review has been completed on the fil-
ter material compatible with silica analysis and variations of
filter body designs have been created and reviewed for suit-
ability. Figure 5 shows the newly designed filter attached to
the CPDM transduce where the respirable dust is collected
during sampling.
Completed Contracts
Feasibility Testing of a Near Real-time Respirable Silica
Monitor—Thermo Fisher Scientific
Thermo Fisher researchers reviewed real-time monitoring
of RCS that may be enabled through the development of
a promising technology: a quantum cascade laser (QCL)
The QCL is a source of IR light that enables the genera-
tion and detection of RCS features in IR spectra. This work
developed and tested hardware and a measurement system
that could be developed into a wearable configuration to
measure respirable silica dust during a miner’s working
shifts. The performance of QCL technology as it relates to a
potentially field-deployable, wearable, near real-time silica
measurement system that supports OSHA and MSHA sil-
ica standards was determined. The weight of the developed
test system was 6.5 pounds and measured 17"× 4"× 6" in
size (408 cubic inches) (Figure 6). This weight and volume
do not include either a battery or main power supply. The
work conducted during this contract has demonstrated that
microgram levels of RCS can be measured utilizing this
detection technique. The presence of coal dust does degrade
detection as compared to RCS alone and therefore, further
research is required to improve the performance.
CONCLUSION
With the proposed silica rule introducing new require-
ments to the mining industry, NIOSH has anticipated the
need for continuing research for developing new near real-
time respirable silica monitors, effective dust controls, and
innovative intervention methods for compliance assistance.
NIOSH maintains a portfolio of research provide infor-
mation, new interventions, and innovative measurement
methods related to respirable coal and respirable silica dust.
Summarizations of the historical research for the
CPDM for respirable coal mine dust measurement and
FAST method for silica measurement were provided. This
summarization describes the timeline for developing both
methods one a near real-time method for RCMD dust mea-
surement the other a step towards real-time measurement
of respirable silica dust. These two projects demonstrate the
successful research accomplished by NIOSH. However, in
Figure 5. The new PVC filter for silica analysis shown
attached to the CPDM transducer where the respirable dust
sample is collected
Figure 6. The prototype of the QCL test system for real-time
measurements of respirable silica dust.
for direct-on-filter measurement by FTIR and Raman
spectrometers and the development of an end-of-shift RCS
quantification method by Raman spectroscopy is also being
performed.
PDM3700-compatible Filter Module Usable with Portable/
Field-Deployable Silica Monitoring Instruments -Thermo
Environmental Instruments
The CPDM is required for sampling at coal mines in the
U.S. by MSHA. The CPDM provides near real-time respi-
rable dust concentrations (concentrations averaged over
a 30-minute time period) and the dust being sampled is
collected on a filter which is ultimately discarded. Thermo
Fisher Scientific is developing a filter module (filter mate-
rial, a holder, and possibly additional supporting elements
and an adaptor) for the CPDM that can be used with a
portable FTIR, QCL, or other infrared (IR) absorption
method that is used to determine the silica content of the
dust being sampled. A review has been completed on the fil-
ter material compatible with silica analysis and variations of
filter body designs have been created and reviewed for suit-
ability. Figure 5 shows the newly designed filter attached to
the CPDM transduce where the respirable dust is collected
during sampling.
Completed Contracts
Feasibility Testing of a Near Real-time Respirable Silica
Monitor—Thermo Fisher Scientific
Thermo Fisher researchers reviewed real-time monitoring
of RCS that may be enabled through the development of
a promising technology: a quantum cascade laser (QCL)
The QCL is a source of IR light that enables the genera-
tion and detection of RCS features in IR spectra. This work
developed and tested hardware and a measurement system
that could be developed into a wearable configuration to
measure respirable silica dust during a miner’s working
shifts. The performance of QCL technology as it relates to a
potentially field-deployable, wearable, near real-time silica
measurement system that supports OSHA and MSHA sil-
ica standards was determined. The weight of the developed
test system was 6.5 pounds and measured 17"× 4"× 6" in
size (408 cubic inches) (Figure 6). This weight and volume
do not include either a battery or main power supply. The
work conducted during this contract has demonstrated that
microgram levels of RCS can be measured utilizing this
detection technique. The presence of coal dust does degrade
detection as compared to RCS alone and therefore, further
research is required to improve the performance.
CONCLUSION
With the proposed silica rule introducing new require-
ments to the mining industry, NIOSH has anticipated the
need for continuing research for developing new near real-
time respirable silica monitors, effective dust controls, and
innovative intervention methods for compliance assistance.
NIOSH maintains a portfolio of research provide infor-
mation, new interventions, and innovative measurement
methods related to respirable coal and respirable silica dust.
Summarizations of the historical research for the
CPDM for respirable coal mine dust measurement and
FAST method for silica measurement were provided. This
summarization describes the timeline for developing both
methods one a near real-time method for RCMD dust mea-
surement the other a step towards real-time measurement
of respirable silica dust. These two projects demonstrate the
successful research accomplished by NIOSH. However, in
Figure 5. The new PVC filter for silica analysis shown
attached to the CPDM transducer where the respirable dust
sample is collected
Figure 6. The prototype of the QCL test system for real-time
measurements of respirable silica dust.