1. AIR TESTING FOR CONTAMINANTS IN MINES
Good afternoon friends and colleagues. I am happy to be here in this beautiful city to talk to you about air testing for contaminants in mines.
I’ve been working in the area of air sampling for more than 24 years, but I must admit I’ve never actually been in a mine.
But I have gone scuba diving in a quarry so that should count for something AND my grandfather spent his working life in a W. PA coal mine or as I like to say STEELERS COUNTRY.

2. TYPICAL AIR CONTAMINANTS IN MINING OPERATIONS
PARTICULATES
Metal fumes from welding operations
Respirable dust including crystalline silica in silica-containing rock and coal dust
Asbestos in asbestos-containing ore
Diesel particulate from engine exhaust
Like most industrial operations, the air contaminants in mining operations include particulates as well as gases/vapors.
Typical particulate contaminants include metals, respirable dustd such as respirable coal dust and crystalline silica, asbestos, and diesel particulate.

3. TYPICAL AIR CONTAMINANTS IN MINING OPERATIONS
GASES AND VAPORS
Naturally occurring methane and hydrogen sulfide
Nitrogen oxides and carbon monoxide from engine exhaust and blasting operations
Formaldehyde from urea-formaldehyde or isocyanates from polyurethane foams
Organic solvents used in cleaning or other applications
Typical air contaminants in the gas/vapor phase include:
-Methane and H2S that are naturally occurring
-Nitrogen oxides and CO from gaseous emissions
-Formaldehyde or isocyanates from foams used to plug up ventilation systems
-Organic solvents used for cleaning

4. AIR CONTAMINANTS IN URANIUM MINING OPERATIONS
Radon-Naturally occurring radioactive gas
Radon Daughters-Fine solid particles which result from the radioactive decay of radon gas; attach themselves to airborne dust and smokes and reach the gas exchange section of the lungs where alpha radiation is emitted.
Uranium mines also have some unique air contaminants:
In the gaseous phase-radon
In the particulate phase-radon daughters which are particles that result of the radioactive decay of radon gas

5. AIR TESTING EQUIPMENT: SO MANY CHOICES
Given these contaminants, what I hope you will gain from our time together today is how to choose the best air testing equipment for your application.
With so many choices in equipment, my best overall advise to you is to FIRST step back and ask some simple questions:
-WHY ARE TAKING THE AIR SAMPLE?
-WHAT ARE YOU GOING TO DO WITH THE RESULTS?

6. CHOOSE YOUR EQUIPMENT: BASED ON YOUR OBJECTIVES
Survey Tool-a direct-reading device that will provide immediate indications of chemical levels in the field. Immediacy of results override limitations in accuracy.
Validated Method-air sample collection followed by laboratory analysis. Accuracy of results override delay in obtaining results.
And then choose your equipment, based on your objectives.
In general, air testing equipment can be classified as either:
-survey tool OR
-validated method
Explain each from slide.

7. CHOOSE YOUR EQUIPMENT: BASED ON YOUR OBJECTIVES
Applications for Survey Tools-
Leak Detection, Confined Space Entry, Hazmat Response, Initial Screening and Spot Checks of Personal Exposure Levels
Applications for Validated Methods-Compliance with Government Regulations, Measurement of Highly Toxic Compounds, and Measurement of Compounds for which direct-reading survey tools do not exist.
There are applications where either a survey tool or a validated method would be the best option.
Read lists.

8. SURVEY TOOLS OPTIONS AND APPLICATIONS
So let’s first take a look at specific SURVEY TOOLS along with the applications for each.

9. GENERAL CATEGORIES OF SURVEY TOOLS
Colorimetric
Technologies
Detector Tubes
Color Badges
Colorimetric Wipes
Colorimetric Swabs
Sensor
Technologies
Catalytic
Photoionization
Electrochemical
Light-Scattering
In my opinion, there are 2 general categories of survey tools. Those based on colorimetric technologies and those based on sensor technologies.

10. SURVEY TOOLS COLORIMETRIC TECHNOLOGIES
We’ll begin by reviewing the options using colorimetric technologies.

11. DETECTOR TUBES A FIRST LINE OF DEFENSE
Classical measurement technique with first patent in 1919
Glass tube containing a chemical media that reacts with the contaminant of interest by changing color
Concentration is read directly from a printed scale on the tube
Tubes now available for measurement of over 200 gases/vapors
First, colorimetric detector tubes.
I would guess that this is the first device most of ever used when learning to do air sampling. It is was surprising to me to learn that this technology has actually been around since 1919.
Since that time, tubes have been continuing developed and colorimetric tubes are now available for measurement of over 200 gases/vapors.

12. TYPES OF DETECTOR TUBES GRAB SAMPLE TUBES
Used with a hand-operated pump to collect on-the-spot measurements
Measurements typically take a few minutes to complete
Pump and tube are calibrated by the
manufacturer as a unit
As the technology advanced, various types of colorimetric detector tubes were developed. The most commonly used detector tubes are described as short-term or grab sample tubes. I assume everyone here has used these tubes.
One issue that seems to come up frequently is whether different brands of tubes can be used with different brands of pumps. Personally, I do not recommend this. The pump and tube are calibrated by the manufacturer of the unit. Even if the air volume is the same, the flow dynamics are different from pump to pump that can affect color chemistry. Piston vs Bellows.

13. LATEST DEVELOPMENT OF DETECTOR TUBE TECHNOLOGY
CHIP MEASUREMENT
SYSTEM (CMS)
Chemical-specific capillary tubes using same technology as short-term tubes
10 tubes on a chip
Used with an electronic analyzer with internal pump and data recorder
In more recent years, Draeger has released a new development in the short-term tube technology called the CMS.
Read slide
SKC 802-series

14. APPLICATIONS GRAB SAMPLE TUBES AND CMS
Qualitative
Leak Detection
Chemical Migration
Confined Space Entry (using extension hose)
Unknown Identification
(using HazMat kits)
Semi-quantitative
Spot checks of area or breathing zone samples
Maximum levels during various processes or worker activities
Analysis of sample bags containing air emissions
Review each and highlight analysis of bags with air flowing under pressure.

15. TYPES OF DETECTOR TUBES PASSIVE TUBES
Break open one end and place in designated holder
Sample from 1-10 hours
Length of stain indicates air concentration in ppm-hr
Divide by hours sampled to obtain ppm concentrations in air
A further development of the long-term detector tubes are passive color tubes that are used for 8 or even 10 hour sampling WITHOUT any pump—hand operated or battery operated.
Review slide.

16. TARGET COMPOUNDS PASSIVE COLOR TUBES
Acetic Acid
Ammonia
Butadiene
Carbon Dioxide
Carbon Monoxide
Ethanol
Hydrochloric Acid
Hydrocyanic Acid
Hydrogen Sulfide
Nitrogen Dioxide
Perchloroethylene
Sulfur Dioxide
Toluene
Trichloroethylene
There are a lot MORE options using the passive tubes. One very popular application is for CO.
Cheap, easy way to sample gaseous emissions. In general industry, they are used a lot for forklift drivers.
Additional passive color tubes available from Gastec.

17. SOURCES OF ERROR DETECTOR TUBES
Accuracy is limited
Interfering compounds cause similar reactions and readings on tube
Affected by temperature and humidity
Subjective differences in “eyeballing” the color change to determine result
Detector tubes are considered a SCREENING TOOL because they do have some inherent sources of error:
Read slide

18. COLOR BADGES IMMEDIATE VISUAL INDICATORS
Badges contain a chemically coated filter paper or “indicator layer”.
Target chemicals in air react with the chemical coating used in the badge and produce a color change.
This change is a visual indicator to the worker that an exposure has occurred.
Color comparison charts allow for exposure estimates.
Now we’ll discuss colorimetric BADGES. These badges are typically worn as personal samplers and they contain…
Read slide.

19. APPLICATIONS COLOR BADGES
Visual indication to evacuate work area in presence of dangerous chemicals
Semi-quantitative exposure level screening
Leak Detection
Warning for Escape
One of the biggest application for this technology is to give a visual indication when working around highly toxic chemicals like phosgene.
My employer, SKC, does not manufacture color badges, but I really like the K and M Environmetal design. When exposed to a highly toxic chemical, an exclamation point appears on the badge.
So your co-worker can EXCLAIM “run for your life”.

20. APPLICATIONS COLOR BADGES
Ammonia
Aniline
Carbon Dioxide
Carbon Monoxide
Chlorine
Dimethyl Amine
Formaldehyde
Hydrazine
Hydrogen Chloride
Hydrogen Sulfide
MDI
Mercury
Nitrogen Dioxide
Ozone
Phosgene
Sulfur Dioxide

21. SOURCES OF ERROR COLOR BADGES
Limited accuracy for quantitative measurements using “dose estimators”
Cross-sensitivities with other chemicals
Temperature and humidity effects
UV light may discolor indicator
The unique source of error with this technology is the fact that UV light may discolor indication over time.

22. COLORIMETRIC WIPES FOR CHEMICALS ON SKIN/SURFACES
Chemicals in air will eventually deposit on skin and surfaces and may pose a risk to workers by skin absorption or ingestion.
Chemical residue on shoes, lunch boxes, and other personal items may inadvertently become a take-home toxin for worker’s family members.
I know this is supposed to be a presentation on AIR sampling, but…

23. FULL DISCLOSURE WIPES FOR LEAD ON SKIN OR SURFACES
Developed by US NIOSH; NIOSH Method 9105
Licensed for production by SKC
Behavior modification tool-Allows workers to determine if their washing/decontamination has been effective.
Can identify down to 18 ug of lead
It’s common knowledge that lead on skin or surfaces can be TOXIC.
To address this concern, NIOSH developed a field detection kit and licensed it to SKC for commercial production.
Read slide.

24. LEAD WIPE KIT FROM SKC
Step 1 Step 2 Step 3
SKC

25. COLORIMETRIC SWABS FOR LEAD IN PAINT AND SURFACES
Self-contained sampling swabs for rapid screening of lead in paint and on surfaces
Squeeze the swab to release the test reagents and then wipe the surface with the swab
Observe color change
Colorimetric swabs also exist for testing lead and other contaminants on surfaces. You can even buy these now at Home Depot and Walmart.
Read slide.
SKC

26. SOURCES OF ERROR COLORIMETRIC WIPES AND SWABS
Cross-sensitivities
Extremely heavy soiling or other contaminants on the test surface may interfere with color development
Persons with color blindness may not be able to detect the color development.
Like with color detector tubes, colorimetric wipes and swabs have sources of error which limit their accuracy.

27. SURVEY TOOLS SENSOR TECHNOLOGIES
Now on to survey tools that employ sensor technologies.

28. CATALYTIC SENSORS COMBUSTIBLE GAS MONITORS
Commonly used since 1959
Test gas or vapor is heated to combustion (burned) and the instrument translates the resulting increase in temperature/resistance as a percentage of the lower explosive limit (LEL).
Oxygen (>10%) is required for the catalytic sensor to operate properly.
One of the most popular direct reading instrument using sensor technologies are combustible gas monitors that employ a catalytic sensor.
In the most simplistic of terms, the principle of operation is that the test gas/vapor is BURNED to produce the reading. Therefore, oxygen is required for this instrument to function properly.

29. APPLICATIONS CATALYTIC SENSORS
Non-specific
measurement of high,
explosive
concentrations
of gases/vapors in air:
Confined space entry
Emergency response
Handheld 5-Gas Monitor including catalytic LEL sensor
SKC 805-series

30. SOURCES OF ERROR CATALYTIC SENSORS
Poisoning or degraded performance can occur when sensor is exposed to certain compounds such as lead-containing compounds, silicones, sulfur-containing compounds, and halogenated hydrocarbons.
Oxygen deficient environments will cause the instrument to produce erroneous readings.
Some of you may be thinking: HEY, why do you consider this a survey tool as we use this in life/death situations.
Well, it is considered a survey tool since it is possible for the instrument to produce erroneous results.
Read slide

31. PHOTOIONIZATION DETECTORS BROAD SPECTRUM VOC MONITORS
Based on the principle that some chemicals can be ionized when hit with high-energy UV light. The instrument measures the resulting current which is proportional to concentration of the gas/vapor in air.
Instrument manufacturers publish technical documents with lists of chemicals that can be detected using UV lamps with various energy levels.
Another very popular survey tool is a PID.
In this case, the test gas/vapor is hit with high-energy UV light which ionizes it producing current of an amount proportional to concentration.
These are widely used as broad spectrum monitors for organic chemicals.

32. APPLICATIONS PHOTOIONIZATION DETECTORS
Non-specific
measurement of ppm
concentrations
of gases/vapors in air:
Leak Detection
Personal Exposures
Spill Delineation
HazMat Response
SKC 730-series

33. SOURCES OF ERROR PHOTOIONIZATION DETECTORS
Non-specific-can not identify specific VOC
Does not detect all VOCs or compounds such as carbon monoxide, hydrogen, methane, oxygen, and formaldehyde
Humidity can cause lamp fogging resulting in lower readings
Sensor drift

34. ELECTROCHEMICAL SENSORS SPECIFIC TO TARGET COMPOUNDS
Contain components designed to react with a specific gas or vapor. The reaction generates a current which is translated into concentration in air.
Sensors available to measure about 20 compounds in the ppm range.
Some cross-sensitivities can occur from other compounds.
Electrochemical sensor technologies are available to measure specific target compounds. After spending more than 25 years in this profession, I am really disappointed that we only have electrochemical sensors for about 20 compounds.

35. APPLICATIONS ELECTROCHEMICAL SENSORS
Measurement of ppm
concentrations
of target gases/vapors in
air:
Leak Detection
Personal Exposures
Confined Space Entry
Spill Delineation
HazMat Response
5-gas monitor
These sensors are widely used in single and multi-gas instruments for a number of applications.
Single-gas monitor

36. SOURCES OF ERROR ELECTROCHEMICAL SENSORS
Cross-sensitivities
Sensor performance and lifetime can be affected by very dry or very humid environments or by brief exposures to high concentrations

37. AEROSOL PHOTOMETERS MEASURE AIRBORNE DUST LEVELS
A light beam is shined through air containing particulate matter. The particulate matter scatters the light beam and the amount of light scattering is measured on a photocell and displayed as mg/m3 concentrations.
Commonly known as “light scattering” instruments
Next, we will discuss sensor technologies for particulate contaminants. You may know these devices as “light scattering instruments” but the technical term actually is “aerosol photometer”.
Sunbeam pouring in through a window.

38. APPLICATIONS AEROSOL PHOTOMETERS
Screening tool evaluating personal dust levels
Perimeter sampling
Internal dataloggers allow for TWA or peak determinations
Internal pumps allow for concurrent sample collection using filters
HazDust IV
SKC

39. SOURCES OF ERROR AEROSOL PHOTOMETERS
Test dust does not produce the same results as the calibration dust; correction factor needs to be determined.
Does not respond to fibrous dusts like asbestos or to small ultrafine dusts.
Note: Most are not intrinsically safe.

40. CALIBRATION IS CRITICAL FOR SENSOR TECHNOLOGIES
All direct-reading
instruments must be
calibrated properly and
regularly.
Both factory and user
calibrations are required.

41. VALIDATED METHODS WITH LABORATORY ANALYSIS
OPTIONS AND APPLICATIONS

42. VALIDATED SAMPLING METHODS WITH LABORATORY ANALYSIS
Published by government or other scientific agencies
Define all the critical sampling parameters for accurately measuring exposures of specific chemicals
Most reliable means of evaluating exposures, but lab analysis takes time
Some of you may be wondering, what are validated sampling methods.
These are SCIENTIFIC DOCUMENTS…
Not analyzed in the field, they are analyzed in an analytical chemistry lab.

43. WEBSITES FOR GOV’T AGENCY METHODS
NIOSH Methods
OSHA Methods
html
The Bible of Air Sampling in the Workplace.
I reference these methods every day of my working life and so does Susan.

44. HELP FROM SKC: SAMPLING GUIDE IN SKC CATALOG
Lists all regulated chemicals
Includes:
Agency Method Number
Sampling Details such as Flow Rate, Time, Volume
Analytical method
Sample collection media and SKC catalog number

45. SKC SAMPLING GUIDE APP Free download of the SKC Sampling Guide App
for Apple or Android
devices.
Visit SKC homepage at
and look
for link for mobile devices.

46. TYPES OF SAMPLES USING VALIDATED METHODS
Active Samples-Require the use of (3) key elements: Pump, Sample Collection Media, Pump Calibrator (Flowmeter).
Passive Samples-Require the use of a passive sampler (badge) that has been thoroughly tested to ensure sampling reliability under various field conditions.
In general terms, there are two types of samples using validated methods:
Explain (3) components of active sampling.
(Focus only on “validated” passive samplers here.)

47. DEFINING PASSIVE SAMPLING
The collection of airborne gases and vapors
at a rate controlled by the physical process of
diffusion WITHOUT the use of a sampling
pump to actively pull air through the sample
collection media.
Everybody understands active sampling means using a pump so let’s take a minute to look at the definition of passive sampling.

48. DEFINING PASSIVE SAMPLING
Chemicals diffuse from
an area of high
concentration in the air to
an area of low concentration
on the sampler.
Based on their mode of
sample collection, passive
samplers are also referred
to as diffusive samplers.
The uptake or sampling rate for individual chemicals must be supplied by the manufacturer of the sampler or the agency that published the validated method.

49. VALIDATED SAMPLING METHODS
GASES AND VAPORS
With that introduction, let’s take a look at the validated sampling methods for typical gases and vapors in mining operations.

50. ACTIVE AIR SAMPLING: USING SORBENT TUBES
Glass tubes containing a sorbent materials are used to trap designated compounds for lab analysis.
Contaminants are ADsorbed onto the surface of the sorbent material and then DEsorbed for laboratory analysis.
The reference method or the gold standard of active sampling involves the use of sorbent tubes.
Contaminants are ADsorbed onto sorbent material and are then DEsorbed for laboratory analysis.
It always disappoints me afte a training class when someone asks me if SKC sorbent tubes are a competitor to Draegr detector tubes.
NO, the technologies go hand-in-hand.
Sorbent Tube

51. SORBENT TUBE SAMPLING: FOR ORGANIC SOLVENTS
Sorbent: Activated Charcoal
Specified in government methods for the collection of common organic compounds including benzene, toluene, and xylene
High adsorptive capacity
Derived from coconut shells

52. SORBENT TUBE SAMPLING: FOR GASEOUS EMISSIONS
Sorbent: Chemically-coated adsorbent
materials
Specified in government methods for the collection gaseous emissions such as nitrogen oxides and formaldehyde
Contaminants react with the chemical coating and produce a stabile compound for analysis.
Example: Nitrogen dioxide is collected using a tube containing carbon molecular sieve sorbent that is chemically-coated with triethanolamine (TEA).
The method will specify the sorbent tube and the SKC catalog will specify the catalog number of the media based on the method.

53. ACTIVE AIR SAMPLING USING SAMPLE BAGS
Used to collect grab samples of an air-contaminant mixture into a flexible container for subsequent analysis
Mining applications include methane, carbon monoxide, and organic solvent vapors.
-Some contaminants like methane and CO will not “stick” to any sorbent material. So to trap the contaminant, you have to place a sample of the air into a sample bag.
-Some times you want to just place the air-contaminant mixture into a container where it can then be easily and rapidly squeezed out into a laboratory instrument for analysis.

54. SAMPLING WITH BAGS TYPES AND APPLICATIONS
TEDLAR® OR SKC
FLEXFILM BAGS
Typically used for the collection of organic vapors.
Designed for short-term storage of up to 1-2 days prior to analysis.
ALUMINIZED OR SKC
FLEXFOIL™ BAGS
Typical mine applications include methane and carbon monoxide.
Can store samples up to 5 days prior to analysis.

55. SAMPLING WITH BAGS SAMPLE COLLECTION OPTIONS
Positive Pressure
Negative Pressure

56. ACTIVE AIR SAMPLING USING CHEMICALLY-COATED FILTERS
Filters are used as a substrate for liquid media that can trap contaminants.
Liquid media will react with the contaminant of interest producing a stabile compound for storage and analysis.
Mining applications include isocyanates such as TDI and MDI.
Another sampling option has been growing in demand in recent years and that is active sampling using chemically-coated filters.

57. SAMPLING TRAIN WITH COATED FILTERS
SKC
for TDI or HDI

58. PASSIVE AIR SAMPLING: FOR ORGANIC SOLVENTS
Validated sampling methods for organic solvents specify the use of passive samplers containing charcoal sorbent.
Methods allow the use of passive samplers for use in collecting 8-hr TWAs or 15-min STELs.
Health and safety professionals and workers LOVE the convenience of passive air sampling.
The good news is that in recent years, US OSHA has been validating these devices for specific compounds.
Methods allow…
SKC 575-series

59. OSHA PASSIVE SAMPLING METHODS: FOR ORGANIC SOLVENTS
Toluene by OSHA 111
Tetrachloroethylene and Trichloroethylene by OSHA 1001
Xylenes and ethyl-benzene by OSHA 1002
MEK and MIBK by OSHA 1004
Benzene by OSHA 1005

60. PASSIVE AIR SAMPLING: FOR FORMALDEHYDE
Validated OSHA Method 1007 specifies a passive sampler that contains a chemically-treated filter paper.
Formaldehyde combines with chemical to form a stabile compound for lab analysis.
OSHA validated passive samplers using a chemically treated filter paper are also available for formaldehyde. The principle of operation is similar to the coated filters used with a pump, but these are passive.
SKC UMEX badge shown here has been validated by US OSHA in Method 1007 for formaldehyde.
SKC

61. VALIDATED SAMPLING METHODS
PARTICULATES
In this application, a filter of a:
SPECIFIC TYPE AND PORE SIZE
Are used (like a sieve) to trap the contaminant of interest.

62. DEFINING PARTICULATE CONTAMINANTS
TOTAL DUST
Particulate matter,
both respirable and
nonrespirable, that can
be trapped onto the
designated filter loaded
into a cassette.
RESPIRABLE DUST
Particulate matter
small enough in size to
penetrate deep into the lung
down to the gas exchange
(alveolar) region.
Particulate contaminants have been traditionally defined as either total dust or respirable dust.
Respirable dust includes those very small particles that can penetrate down deep in to the lung. While total dust includes both the small respirable and larger dust particles.

63. TOTAL DUST VS RESPIRABLE DUST SAMPLERS
The sampling equipment for total and respirable dust sampling is similar. The only difference is a size-selective device namely a cyclone is placed on the inlet of the filter for respirable dust sampling.
Total Dust Samplers
Respirable Dust Samplers

64. AIR SAMPLING FOR PARTICULATES IN MINING OPERATIONS
Air sampling is done using
filters loaded into
cassettes WITHOUT
cyclones for:
Metals
Asbestos
Radon Daughters
Air sampling is done using
filters loaded into
cassettes WITH
cyclones for:
Respirable Crystalline Silica and Coal Dust
Diesel Particulate Matter (DPM)
When deciding whether to use a cyclone or not, you should review how the contaminant is regulated and the specifications of the published method.
Read slide

65. TOTAL DUST SAMPLING TIP
The filter-cassette is clipped on the worker’s lapel in the breathing zone with the inlet of the sampler pointing downwards—just like your nose.
Remove the small plug only from the inlet.
Watch for filter overloading.

66. AIR SAMPLING: FOR ROUTINE METALS
Most metals can be collected onto 37-mm, 0.8 um pore size MCE filters.
The Metal/Nonmetal Inspection Handbook recommends a pump flow rate of 1.7 L/min.
Laboratory chemical analysis of the filter can determine the type of metals and amount present in air.

67. AIR SAMPLING: FOR HEXAVALENT CHROMIUM
Some metals such as hexavalent chromium (Cr+6) will require alternative sampling media and special sample handling procedures.
Cr+6 sampling requires the use of a 5 um pore-size PVC filter at a typical flowrate of 1.7 L/min.
Filters should be removed from the cassette, placed into vial, and rushed to the laboratory.

68. AIR SAMPLING: FOR HEXAVALENT CHROMIUM
Samples are rushed by overnight shipment to the laboratory because interfering compounds in the test atmosphere can cause the collected Cr+6 to convert to Cr+3 upon storage.
Interfering compounds include Fe+2 in welding applications.

69. AIR SAMPLING: FOR OTHER SPECIALTY METALS
Other specialty metals such as silver, calcium, and mercury use the standard MCE filter for sampling, but require the use of a separate filter/cassette due to special handling in analysis.
It is imperative that you communicate with your analytical laboratory PRIOR to sampling to ensure proper procedures are followed.

70. AIR SAMPLING: FOR METALS IN WELDING
MSHA advises that the filter-cassette sampler should be positioned beneath the welder’s helmet when the helmet is placed down.
A convenient welding helmet adapter has been developed by a Canadian agency for this application. Leather straps and flexible metal in the tubing allow for easy cassette placement.

71. WELDING HELMET ADAPTER
Note also 25-mm cassette can be used instead of 37-mm cassette.
SKC

72. REGULATORY NEWS: ASBESTOS
Effective April 2008, MSHA issued a new PEL for asbestos of 0.1 fiber/ml of air, reduced from 2 fibers/ml.
A new excursion limit of 1 fiber/ml for 30 minutes was also issued.
The MSHA exposure limits for asbestos are now consistent with those issued by OSHA.

73. AIR SAMPLING: FOR ASBESTOS
Asbestos samples are collected using 25-mm, 0.8 um pore size filters loaded into black, conductive cassettes.
The filter cassettes have a cylinder cowl as the middle section that protects the filter and ensures a uniform fiber deposition.
The cowl should point downwards when sampling and the cassette inlet piece should be removed to allow for open-face sampling.
Keep in mind, the analysis method is MICROSCOPY. So this cowl, protects the filter from fingerprints and gives even deposition.

74. AIR SAMPLING: FOR ASBESTOS
After sampling, filters are analyzed microscopically so filter loading is critical.
For full-shift sampling, the Metal/Nonmetal Inspection handbook recommends a flowrate of 1.7 L/min for air volumes of L.
For short-term sampling of minutes, flowrates of 1.7 L/min to 2.5 L/min or higher are recommended for optimal filter loading.

75. AIR SAMPLING: FOR RADON DAUGHTERS
Pump and filter sampling is done at a flow rate of 2 L/min using 25-mm glass fiber filters loaded into a cassette holder as shown.
The filter is placed in the holder with the semi-smooth “waffled” pattern facing the pump and the rough side exposed to the air.
Collect a 5-minute sample and count the sample using a radiation counter within 90 minutes.

76. WHY USE A RESPIRABLE DUST SAMPLER ?
Some air contaminants such as silica are regulated as respirable dust. Collecting larger, non-respirable particulates would inflate the results overestimating exposure.

77. CYCLONES: TRADITIONAL RESPIRABLE DUST SAMPLERS
Cyclones are named for the rotation of air within a chamber
Function on the same principle as a centrifuge
Use centrifugal force to separate particles according to their aerodynamic diameter

78. CYCLONE OPERATION
Air enters through a slit on the side of the sampler which creates cyclonic action.
Large particles fall into red “grit pot” and are discarded.
Small particles are thrown onto the filter for analysis.
Cap must be in place.

79. DIFFERENT CYCLONE OPTIONS
All cyclones are not created equal!
Each cyclone has different operating specifications and performance criteria.
Be sure you know the flow rate specified to achieve the desired cut-point before using a cyclone.

80. A NEW RESPIRABLE DUST SAMPLER FROM SKC
SKC has developed an impactor based sampler for respirable dust called the Parallel Particle Impactor or PPI.
Single-use,disposable PPI models are available for use at either 2, 4, or 8 L/min.

81. SKC RESPIRABLE PPI: FUNCTIONALITY
The disposable models of the PPI look and function very much like a traditional 37-mm cassette.
But the inlet comes pre-loaded with size-selective impactor plates that scrub out the non-respirable portion.
PPI samplers are smaller than traditional cyclones and can fit under a welder’s helmet or other PPE.
SKC calls this sampler a Paralled Particle Impactor or PPI and here you can see the operating principle.
Read bullets.
Note that you are NOT concerned about how much particualte is collected at each of the individual inlets, but only what is collected on the final filter.
This is a precise match to the current collection efficiency curves.

82. 50% CUT-POINT: A PERFORMANCE SPECIFICATION
The 50% cut-point is often used to describe the performance of respirable dust samplers including cyclones.
It is the particle size that the device can collect with 50% efficiency.
Particles smaller than the 50% cut-point of the cyclone are collected with an efficiency greater than 50%.
Larger particles are collected with an efficiency less than 50%.

83. RESPIRABLE DUST SAMPLERS: CURRENT U.S. CRITERIA
Existing U.S. MSHA and OSHA regulations specify the use of respirable dust samplers with a 50% cut-point of 3.5 um.
But in 2013, OSHA issued a proposed rulemaking for respirable crystalline silica specifying the use of samplers with a 50% cut-point of 4.0 um. This is consistent with NIOSH, ACGIH, and other organizations.

84. CYCLONE CALIBRATION TIP
Cyclones can be placed inside calibration jars to measure the flowrate through the inlet.
Take care when using calibration jars with piston-style calibrators such as the DC-Lite or Defender.
SKC

85. CYCLONE CALIBRATION TIP: PISTON STYLE FLOWMETERS
The “dead” volume in the jar
can affect the rise/fall of the
piston causing the readings to
be erroneously low.
Options:
Use calibration adapters if available.
Attach cyclone to calibrator pressure port and pump to suction port.
Use smallest calibration jar possible.
SKC

86. CYCLONE SAMPLING TIP: SAMPLER CLEANING
Failure to clean the cyclone after sampling can
affect size-selection on future samples:
After sampling, clean all parts of the cyclone, with mild soapy water
Don’t forget to clean the grit pot.
Dry the cyclone. (Air-dry or blow-dry)
Wipe with a dust-free tissue or wipe with an isopropyl alcohol moistened pad.
Caution: Do not use strong solvents to clean plastic cyclones

87. DIESEL PARTICULATE MATTER (DPM)
MSHA issued a final rule on DPM for underground metal/non-metal miners effective May 2008.
PEL is 160 ug/m3 as Total Carbon: Elemental Carbon plus Organic Carbon
(EC + OC).

88. AIR SAMPLING: FOR DPM
MSHA requires that DPM samples be collected using a specialty filter cassette. (SKC ).
This filter cassette contains an internal impactor plate that separates DPM from other respirable particulate based on size.
Larger respirable particles impact and are removed while DPM particles collect onto the heat-treated quartz filter.

89. DPM filter cassette-SKC Cat. No. 225-317
Note that SKC features the GS-1 cyclone with the DPM sampler on the right hand column of page 89. This is because the GS cyclone with the single inlet is a close match to the Dorr-Oliver nylon cyclone. At this time, the only cyclone that can be used by US MSHA inspectors is the Dorr-Oliver or “an equivalent”.
For your applications, any cyclone that can be attached to the DPM filter cassette can be used. It is only scrubbing out the large particles so they do not overload the filter.

90. DPM SAMPLING TRAIN Cyclone
Removes non-respirable particles that may overload the filter
Internal Impactor Plate in Cassette
Removes respirable particles greater than 1.0 um in diameter
After-filter assembly
Collects DPM particles less than 1.0 um in diameter for analysis of EC and/or OC.

91. AIR SAMPLING: FOR DPM
Samples are collected at 1.7 L/min or 2.0 L/min for the full-shift.
Again, it is important not to invert the sampler during the sampling period.
After sampling the filters are sent to the laboratory for analysis following NIOSH Method 5040.

92. AIR SAMPLING METHODS SKC CAN HELP
So many contaminants, so many choices….
SKC CAN HELP