Respirable Crystalline Silica (RCS)Understanding the Regulations, Science & Results
Marc Hugus
Manager, Business Development
MTA-PALMS RCS – Understanding the Regulations, Science & Results 2
Marc Hugus – Manager, Business Development
Over 30 years consultative technical business development, sales and marketing experience in Oil and Gas, Engineering, Environmental Consulting and Automated Mapping and GIS
Bachelors and Masters degrees in Geography
Over 6 years experience in environmental and industrial hygiene laboratory sales and customer service
Knowledgeable in OSHA and EPA regulations for air, water, soil and industrial hygiene sampling and analysis
Involved with IPO’s for 4 companies, including MapQuest.com
MTA-PALMS RCS – Understanding the Regulations, Science & Results 3
What is Silica?
• Family of materials consisting of silicon dioxide (SiO2)
– Crystalline mineral and amorphous material
• Concern is Crystalline Form
– a solid 3D structure of SiO2 atoms having fixed distances, preferred orientation(s) and arrangement
– Quartz is the most ubiquitous compoundon earth (~43% by weight)
Regulated Crystalline Silica Polymorphs (Respirable)
Quartz TridymiteCristobalite
MTA-PALMS RCS – Understanding the Regulations, Science & Results 4
What is a Respirable Particle?• < 10 microns (aerodynamic mass diameter)
• Inhaled particles can reach deep regions of lung (Alveoli)
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10 11
Aerodynamic Diameter (microns)
Fraction Collected (%)
2015 ACGIH TLVs and BEIs Appendix C
MTA-PALMS RCS – Understanding the Regulations, Science & Results 5
Exposure to Crystalline Silica
• Source material – Nature….rocks– Igneous – granite, other felsic igneous rocks
– Sedimentary – sandstone, shale, carbonates
– Metamorphic – schist, gneiss, quartzite, etc.
• How is it released?– Pulverized, crushed, fractured, etc.
• Potential risk for delayed health effects:– Silicosis
– Lung cancer
– Chronic obstructive pulmonary disease (COPD)
– Kidney disease
MTA-PALMS RCS – Understanding the Regulations, Science & Results 6
Work Activities of Concern
• Stone Cutting, Grinding and Polishing
• Foundry Operations
• Sand Blasting
• Manufacturing (e.g. Glass and Ceramics)
• Building Demolition/Renovation
• Concrete, Masonry and other Construction Materials
• Mining/Quarrying (various)
• Materials Handling/Packaging
• Bulk shipping/Transportation
• Agriculture
• Etc.
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Assess, Recognize, Evaluate, Control & Confirm
• Review possible risks and exposures- Risk = Exposure (amount and duration) X Potential Toxicity
• Implement OEHS program(s)
• Evaluate containment capabilities- Conduct containment assessment
• Enhance containment systems- Work practices- Engineering controls
• Re-evaluate and confirm controls- Conduct exposure assessment
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“New” OSHA Rules Summary
• Permissible Exposure Limit (PEL) reduced to 50 mg/M3 for 8 hour TWA
• Action Level (AL) reduced to 25 mg/M3 for 8 hour TWA
• Key Dates- Construction – September 23, 2017
- General Industry/Maritime – June 23, 2018- Hydraulic Fracturing* – June 23, 2018
*Engineering Controls – June 23, 2021
• On-going evaluation– If above AL but below PEL – Reevaluate exposure within 6 months
– If above PEL – Reevaluate exposure within 3 months- If below AL – Repeat monitoring within six months (2 samples at least 7 days apart) to confirm controls
– Changes in the production, process, control equipment, personnel, or work practices
MTA-PALMS RCS – Understanding the Regulations, Science & Results 9
OSHA Record Keeping
Exposure Monitoring – Air Sampling – Sample dates and tasks
– Sampling and analytical method used
– Number, duration and results for samples
– Laboratory identity
– PPE utilized during sampling
– Social Security Numbers for employees covered
Objective Data– Materials in question
– Comparable industry/task data sources
– Testing protocols/results
– Descriptions of processes and tasks
– Other relevant data
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Various Sampling and Lab Methods(Crystalline Silica on Filters)
• MSHA – P7 (FTIR) – coal mines
• MSHA – P2 method (XRD) – metal/non metal mines
• NIOSH – 7500 (XRD)
• NIOSH – 7602 (IR-KBr pellet)
• NIOSH – 7603 (IR-redeposition)
• OSHA – ID 142 (XRD) – similar to NIOSH 7500
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NIOSH 7500 Method Summary
• OSHA approved for analysis of silica in airborne dust
• Filter redisposition- Polyvinyl Chloride (PVC)
• Analysis by X-Ray Diffraction (XRD)
MTA-PALMS RCS – Understanding the Regulations, Science & Results 12
Polyvinyl Chloride (PVC) Filters
• Suitable for multiple NIOSH/OSHA/ASTM air sampling methods
• Silica
• Metals
• Dust (silica-free, low ash)
• Hydrophobic - low tare weight and moisture pickup for gravimetric stability
• Non-oxidizing surface
• Standard pore size 5mm for silica
Secondary electron image of
a PVC filter
MTA-PALMS RCS – Understanding the Regulations, Science & Results 13
Sample Collection
Sample Date Sample No. Sample Description MediaPump
No.
Pre-Flow
Rate
(L/min)
Start Time
Post-Flow
Rate
(L/min)
Stop TimeAvg. Flow
Rate
Total Time
(min)
Volume
(L)Analysis
Personal - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500
Personal - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500
Area 1 - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500
Area 1 - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500
Area 2 - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500
Area 2 - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500
PDR - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500
Field Blank PVC (5.0) 0.0 0 0.0 NIOSH 0500
Field Blank PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500
Relinquished by: Date/Time
Method of Shipment: Hand delivered
Received by: Date/Time
Sample Condition Upon Receipt: Acceptable Other (explain on reverse)
XYZ Company Sample Collection Record
Chai
n o
f C
ust
ody
Page of
ATTENTION TO:Project No.: Client No.:
Date Logged In: Logged In By:
Name: Name: Email:
Company: Company: Fax:
Address: Address:
City, State, Zip: City, State, Zip:
Phone: Fax: Phone:
Call with verbal results:
Email results to:
Fax results to:
Accreditations required to be followed: yes no
Sample
Date
Relinquished By (Signature): Date: Time: Received By (Signature): Date: Time:
Relinquished By (Print Name): Received By (Print Name):
Company Name: Method of Shipment: Company Name: Method of Shipment:
Relinquished By (Signature): Date: Time: Received By (Signature): Date: Time:
Relinquished By (Print Name): Received By (Print Name):
Company Name: Method of Shipment: Company Name: Method of Shipment:
Sample
LocationSample Description
Quality System
Requirements
(if applicable)
Circle which ones
to follow:
Analysis Requested Special Instructions or Comments
ISO (Please specify):
cGMP:
Other (Please specify):
Client Sample ID
Relinquished To:
Relinquished To:
Chain of
Custody
Chain of
Custody
Chain of
Custody
Chain of
CustodyRelinquished To:
Send
Invoice
To
Relinquished To:
Date Results
Requested
Yes
Lab Use
OnlyClient Job Number:
Standard TA assumed if left blank;
please do not use vague terms like ASAP
Request for Laboratory Analytical Services - Chain of Custody
Rush Charges
Authorized ?
(circle one)
Purchase Order Number:
No
Report
Results
To
MTA-PALMS RCS – Understanding the Regulations, Science & Results 14
Size Selective Sampling – Cyclones
Cyclone
10-mm nylon cyclone
Higgins-Dewell (HD) cyclone
SKC Aluminum cyclone
BGI GK 2.69 cyclone
Flow Rate
1.7 L/min
2.2 L/min
2.5 L/min
4.2 L/min
• Ensure the cassette is loaded into the cyclone properly
• Do not invert sampler assembly while using the cyclone Air Inlet
Grit pot
Coarse
Respirable
MTA-PALMS RCS – Understanding the Regulations, Science & Results 15
Sampler Calibration
• Calibrate flow rate to primary standard
• Include entire sampling train
• Direct flow check (rotameter) or Bell Jar (“old school”)
• Check flow rate before and after sampling
MTA-PALMS RCS – Understanding the Regulations, Science & Results 16
SKC PPI Sampler
• Parallel Particle Impactor (PPI) from SKC, Inc.
• Alternative sampler- Eliminates need for cyclone (no inversion issues)- Compatible with multiple sampling pumps- Available in 2L, 4L and 8L- Increases worker comfort
• OSHA approved
MTA-PALMS RCS – Understanding the Regulations, Science & Results 17
Exposure Monitoring Tips
• Inspect and Test Equipment
– Cassettes for cracks/leaks
– Integrity of tubing
– O-rings and seals
– Clean cyclone and grit pot
• Orientation of Sample Inlet and Cyclone
• Maximize Sampling Air Volume
• Know Where your Sampler has Been
• Augment with Direct-reading Instruments
• Avoid Sampler Contact with Settled Dust
• Moderate Potential Interferences
MTA-PALMS RCS – Understanding the Regulations, Science & Results 18
NIOSH 7500 Laboratory Analysis
Follow a Sample throughthe Laboratory
MTA-PALMS RCS – Understanding the Regulations, Science & Results 19
X-Ray Diffraction (XRD)
• Used to Evaluate Crystalline Materials
• NIOSH 7500, Crystalline Silica by XRD
• Three regulated crystalline silica minerals
- Quartz, cristobalite, and tridymite- Other methods may not differentiate the 3 polymorphs
MTA-PALMS RCS – Understanding the Regulations, Science & Results 20
Cassette Assembly
• Filters Used (typical)– 5 µm pore size
– 37 mm diameter
– Polyvinyl chloride (PVC)
• Pre-weights– Weighed in sets of 10
– Every 10th weight is re-weighed to ensure that the balance did not drift during weighing of the set
MTA-PALMS RCS – Understanding the Regulations, Science & Results 21
Cassette Assembly (continued)
• Assemble Cassette– 2 or 3 piece depending on
cyclone
– SKC PPIs
• Tracking Number– Unique ID for each cassette
– Identifies pre-weight of filter and time/date of assembly
MTA-PALMS RCS – Understanding the Regulations, Science & Results 22
Sample Preparation (1)
• Samples received
• Dried in a desiccator
• Cassettes carefully opened to remove filters
• Filters post-weighed
• Total respirable dust mass calculated
‘Gravimetric Analysis’NIOSH 0500NIOSH 0600
MTA-PALMS RCS – Understanding the Regulations, Science & Results 23
Sample Preparation (2)
• NIOSH 7500 Options
– Low temperature plasma ashing (beaker)
• 1 hour @ ~ 150°C
– Muffle furnace ashing(crucible)
• 2 hour @ 600°C
– Filter dissolution
• Tetrahydrofuran (THF)
MTA-PALMS RCS – Understanding the Regulations, Science & Results 24
Sample Preparation (3)
• 15 mL of 2-Proponal is added to each beaker
• Cover and sonicate
• Obtain a silver membrane filter
– 25 mm
– 0.45 µm
• Attach funnel
MTA-PALMS RCS – Understanding the Regulations, Science & Results 25
Sample Preparation (4)
• Pour suspension into the funnel
• Rinse walls of beaker
• Apply vacuum
• Remove the silver filter with the sample deposited on it
MTA-PALMS RCS – Understanding the Regulations, Science & Results 26
Sample Preparation (5)
• Mount into XRD holder
• Place in orderly fashion
• Ready for analysis
MTA-PALMS RCS – Understanding the Regulations, Science & Results 27
X-Ray Diffractometer
PANalytical Cubix3 Diffractometer
X-raySource
Detector
Goniometer
Sample
MTA-PALMS RCS – Understanding the Regulations, Science & Results 28
XRD Basics
• Bombardment of X-rays results in scattering of the X-rays off of atomic planes
• X-Ray diffraction produces patterns that are indicative of the atomic planes in a material, which serve as a fingerprint for individual minerals
d
Incident X-ray beam
Diffracted beam
q
qAtomic Planes
λ
λ = 1.54 Å, CuKa
nλ=2dsinΘ
MTA-PALMS RCS – Understanding the Regulations, Science & Results 29
XRD Data
Position [°2Theta] (Copper (Cu))10 20 30
Counts
0
40000
160000
360000
MTA-PALMS RCS – Understanding the Regulations, Science & Results 30
XRD Data
QuartzSilverSilver Chloride
Position [°2Theta] (Copper (Cu))10 20 30
Counts
0
40000
160000
360000
Primary Quartz Peak
Secondary Quartz Peak
Primary Silver Peak
MTA-PALMS RCS – Understanding the Regulations, Science & Results 31
NIOSH 7500 - External Standard Method
• Create standards from a pure mineral
• Construct a calibration curve
• Compare unknown samples to known standard
results to determine silica quantification
MTA-PALMS RCS – Understanding the Regulations, Science & Results 32
Calibration Standard Data
100 µg Qtz
10 µg Qtz
5 µg Qtz
25 µg Qtz
Blank
250 µg Qtz
50 µg Qtz
Quartz Detection Limit2.5 µg Qtz
MTA-PALMS RCS – Understanding the Regulations, Science & Results 33
XRD Method Potential Interferences
• Mica*
• Potash
• Feldspars*
• Zircon
• Graphite
• Aluminosilicates
Best way to determine interferences: collect a bulk settled dust sample or send the bulk material in
question for XRD analysis for phase identification.
MTA-PALMS RCS – Understanding the Regulations, Science & Results 34
Lower LOQ Analysis
• Detection limit reduced by 50%- 2.5 mg vs 5.0 mg
• Accomplished through advanced instrumentation and software upgrades
• Requires additional sample prep and analysis
• AIHA LAP Approved
• Uniquely available from RJ Lee Group
MTA-PALMS RCS – Understanding the Regulations, Science & Results 35
Standard vs. Enhanced Spectral Analysis
Standard analysis 5.0 mg/filter
Enhanced analysis 2.5 mg/filter
MTA-PALMS RCS – Understanding the Regulations, Science & Results 36
Advantages of Lower LOQ
• Low sample volume on filter- Short duration sample event- “Clean” working environment
• Requirement for numerical reporting below industry standard
• Environmental (ambient/fence line) monitoring
MTA-PALMS RCS – Understanding the Regulations, Science & Results 37
RJ Lee Group, Inc.
350 Hochberg Road, Monroevi l le, PA 15146
Tel : (724) 325-1776 | Fax: (724) 733-1799
LABORATORY REPORT
ABC Company
1 Industrial Way
Pittsburgh, PA 15200 REPORT DATE June 4, 2014
ATTENTION: Crystal N. Silica SAMPLES RECEIVED May 30, 2014
TELEPHONE: 724-XXX-XXX RJ LEE GROUP JOB NO. PA30052014001
CLIENT JOB NO. N/A
ANALYSIS: Respirable Dust and Crystalline Free Silica Dust on 5 µm PVC Air Filters PURCHASE ORDER NO: N/A
METHODS: Gravimetry, NIOSH 0600 and X-Ray Diffraction, NIOSH 7500
LOD: 0.005 mg Quartz , Cristobalite, and Tridymite 0.100 mg Respirable Dust
Air* Respirable Masses of Free Weight Percentages of Airborne Dust
Sample Identification Volume Dust Mass Silica Minerals (mg/filter) Crystalline Silica Minerals Concentrations (mg/m3)
Client I.D. RJ Lee Group (liters) (mg/filter) Quartz Cristobalite Tridymite Quartz Cristobalite Tridymite Respirable Quartz Cristobalite Tridymite
Sample A 001 1200. 0.500 0.500 < 0.005 < 0.005 100.0 < 1.0 < 1.0 0.417 0.417 < 0.004 < 0.004
Sample B 002 1200. 0.500 0.250 < 0.005 < 0.005 50.0 < 1.0 < 1.0 0.417 0.208 < 0.004 < 0.004
Sample C 003 1200. 0.500 0.150 < 0.005 < 0.005 30.0 < 1.0 < 1.0 0.417 0.125 < 0.004 < 0.004
Sample D 004 1200. 0.500 0.100 < 0.005 < 0.005 20.0 < 1.0 < 1.0 0.417 0.083 < 0.004 < 0.004
Sample E 005 1200. 0.500 0.050 < 0.005 < 0.005 10.0 < 1.0 < 1.0 0.417 0.042 < 0.004 < 0.004
Blank 006 N/A < 0.100 1.050 < 0.010 < 0.010 N/A N/A N/A N/A N/A N/A N/A* Supplied by the client.
N/A Not Applicable
Air volume during a worker’s
shift
Mass of material on filter from
micro-balance
Mass of mineral
Mass of total dust× 100
Mass
Air Volume× 1000
Standard Report Overview
MTA-PALMS RCS – Understanding the Regulations, Science & Results 38
• Balance
– Calibration – daily
– Gravimetric test samples
• Calibration Curve
– Reanalyze and re-measure standards (every 3 mos.)
– CCV – Continuing Calibration Verification – Set of standards run after every 10th sample
• To ensure the calibration curves remain accurate
– RL – Reporting limit – Set of standards run daily
• To ensure that tube intensity is strong enough to see the RL (0.5µg)
• Sample Preparation
– Blanks – every day
• To check for cross contamination between samples during preparation
• Analysis
– 10% of unknown samples are re-measured by a second analyst
– 10% of CCVs and RLs are re-measured by a second analyst
• Audits
– AIHA audit – every 2 years
– Internal audits – annually
Quality Assurance
MTA-PALMS RCS – Understanding the Regulations, Science & Results 39
Lab Considerations
• Laboratory Selection– Sample preparation per method considerations
– Capability to address interferences
– Quality assurance and accreditation
– Detection limits
– Sampling guidance and support
• Technology Advancement– Sample concentration and sampling methods
– Advances in instrumental analysis / optimization
MTA-PALMS RCS – Understanding the Regulations, Science & Results 40
Marc Hugus: [email protected]
RJ Lee Group
Using the power of science to prove your products safe and
environmentally friendly