Personal Air Sampling for Crystalline Silica Exposure

| |

Summary Statement

This PowerPoint was presented on April 14, 2016 to the NASA industrial hygiene community as part of a video teleconference on the new silica standard. There is another PowerPoint presented by CPWR staff for the NASA video teleconference. This short PPT covers the traditional methods for collecting and analyzing respirable crystalline silica samples. Traditional cyclonic separators, like the Dorr-Oliver are reviewed, but newer units that allow higher flow rates and, therefore, lower detection limits are also highlighted. CPWR does not endorse particular brands of equipment, but appreciates Ron Roberson of Sensidyne allowing us to post this PowerPoint.
April 2016

worker with machine making dust

Traditional Sampling Methods for Respirable Crystalline Silica

  • NIOSH 7500: Crystalline Silica via XRD
  • NIOSH 7601: Crystalline Silica via Visible Spec
  • NIOSH 7602: Crystalline Silica via IR
  • OSHA ID-142: Crystalline Silica via XRD
  • Field methods were similar, but lab method varied

Traditional Cyclones for Respirable Silica Sampling

Dorr-Oliver 10 mm Nylon Cyclone

  • Dorr-Oliver 10 mm Nylon Cyclone at 1.7 LPM

Higgins-Dewell Cyclone

  • Higgins-Dewell Cyclone at 2.2 LPM

Aluminum Cyclone

  • Aluminum Cyclone at 2.5 LPM

Cyclone Calibration Jar For Dorr-Oliver Cyclone

Cyclone callibration set up with tubing, Electronic Bubble Meter, Cyclone calibration Jar, and Sampling pump

Particle Size Distribution-US ACGIH

graph- percent penetration s curve to Aerodynamic Diameter

High Flow Rate Cyclones

GK 2.69

  • GK 2.69 at 4.2 LPM (37mm NIOSH Cassette)

GK 4.162 Rascal model

  • GK 4.162 RASCAL at 9 LPM (47mm)

FSP-10 model

  • FSP-10 at 11.2 LPM (37mm Euro Cassette)

NIOSH Testing of High Flow Cyclones

  • Performance of High Flow Rate Samplers for Respirable Particle Collection; NIOSH; Lee, Kim, Chisolm, Slaven & Harper; Amer Occup Hyg; Vol 54, No. 6, 2010.
  • Quartz Measurement in Coal Dust with High-Flow Rate Samplers: Laboratory Study; NIOSH; Lee, Lee, Kim, Chisolm, Kashon & Harper; Amer Occup Hyg; Vol 56, No. 4, 2011.

Gilian Cyclones

Cyclone Model Part Number Construction Material Overall Height (mm) Approx. Weight (Kg) Flow rate ACGIH Resp (50% @ 4μm) (US) Flow rate BMRC Respirable (50% @ 5μm) (Europe) Flow rate Thoracic (50% @ 10μm)
10 mm Dorr-Oliver 800061 Nylon 160 0.08 1.7 LPM    
BGI-4L, HD style (US version) 811-9924-01 Aluminum 105 0.15 2.2LPM 2.0 LPM 1.0 LPM
FSP-2HD style-European Version 811-9930-01 Aluminum 130 0.14 2.2 LPM 2.0 LPM  
Medium flow rate GK 2.69 for 37 mm cassettes 811-9926 Aluminum 125 0.10 4.2 LPM   1.6 LPM
High flow rate RASCAL Cyclone with Plastic Filter Holder 811-9925-01 Aluminum 170 0.26 8.5 to 9.5 LPM    
FSP-10, High flow rate cyclone 811-9931-01 Aluminum 203 0.26 11.2 LPM 10 LPM  

Gilian 10i High Flow Sampling Pump

Gilian 10i High Flow Sampling Pump
  • 4 – 10 LPM Flow Rates
  • Backpressure Capability up to 50” H2O @ 4 LPM
  • Intrinsically Safe Certified
  • Built on the Proven-reliable Gilian 5000 Platform

Gilian 12 High Flow Sampling Pump

Gilian 12 High Flow Sampling Pump picture

  • Flow Rates from 4 – 12 LPM
  • Extreme Backpressure Capability to 67” H2O @ 4LPM
  • Designed for high Flow Rate Cyclones
  • Ideal for Sampling Trains Creating High Backpressure Across the Entire Sampling Period

Appendix A: Methods of Sample Analysis

  • “This appendix specifies the procedures for analyzing air samples for respirable crystalline silica, as well as the quality control procedures that employers must ensure that laboratories use when performing an analysis required under 29 CFR 1926.1153 (d)(2)(v)”.
  • References the six methods as acceptable for the laboratory analysis methodology & specifies minimum QA.
  • Makes the statement: “Optimizes methods and instruments to obtain a quantitative limit of detection that represents a value no higher than 25 percent of the PEL based on sample air volume”.

Methods Listed in Silica Standard For Lab Reference

Method No. Analysis LDL (1.7LPM)
OSHA ID-142 XRD, Redeposition 12.0 μg/m3 (qtz)
NIOSH 7500 XRD, Redeposition 6.12 μg/m3 (8 hr)
NIOSH 7602 IR, KBr Pellet 6.12 μg/m3 (8 hr)
NIOSH 7603 IR, Redeposition 12.24 μg/m3 (8 hr)
MSHA P-2 XRD, Redeposition 24.48 μg/m3 (8 hr)
MSHA P-7 IR, Reseposition 24.48 μg/m3 (8 hr)

Air Sampling Review

  • Must have a large enough sample to obtain a maximum limit of detection of 12.5 micrograms per cubic meter (i.e., 25% of 50 micrograms per cubic meter).
  • Must use the analysis by XRD or IR, as described in the six listed methods.
  • The laboratory must meet minimum specified QA requirements.

Air Sampling Equipment Review

  • Always observe the cyclone flow rate specification for meeting the ACGIH size selection curve (50% at 4 microns).
  • Always use a constant flow control pump that will keep the flow rate at +/- 5% of set flow.
  • A medium flow cyclone can meet the detecting limit in an 8 hour sample and still be comfortable to wear.

Sunsidyne logo
800-451-9444 / 727-530-3602


A company of the SCHAUENBURG International Group
Schauenburg International Group logo