Evaluation of Flow Controllers Used with Evacuated Canisters to Assess VOC Exposures in Occupational and Non-Occupational Environments

Details

• Personal Author:
  Carroll M ; LeBouf, Ryan F. ; Lutes C ; Rossner A ; Wick DP
• Description:
  Ideally, measuring exposures to volatile organic compounds should allow for modifying sampling duration without loss in sensitivity. Traditional sorbent-based sampling can vary sampling duration, but sensitivity may be affected when capturing shorter tasks. Diaphragm and capillary flow controllers allow for a range of flow rates and sampling durations for air sampling with evacuated canisters. The goal of this study was to evaluate the extent to which commercialized capillary flow controllers satisfy the bias (+/- 10%) and accuracy (+/- 25%) criteria for air sampling methods as established by the National Institute for Occupational Safety and Health (NIOSH) using the framework of ASTM D6246 Standard Practice for Evaluating the Performance of Diffusive Samplers to compare their performance with diaphragm flow controllers in a long-term field study. Phase 1 consisted of a series of laboratory tests to evaluate capillary flow controller flow rates with respect to variations in temperature (-15-24 degrees C). The results demonstrated a slight increase in flow rate with lower temperatures. In Phase 2, the capillary flow controller was evaluated utilizing a matrix of parameters, including time-weighted average concentration, peak concentration (50-100× base concentration), air velocity across the sampler inlet (0.41-0.5 m/s), relative humidity (20-80%), and temperature (10-32 degrees C). Comparison of challenge concentrations with reference concentrations revealed the aggregate bias and overall accuracy for four tested compounds to be within the range of criteria for both NIOSH and ASTM standards. Additionally, capillary flow controllers displayed lower variability in flow rate and measured concentration (RSD: 2.4% and 4.3%, respectively) when compared with diaphragm flow controllers (RSD: 6.9% and 7.2%, respectively) for 24-hr laboratory tests. Phase 3 involved further testing of flow rate variability for both diaphragm and capillary flow controllers in a field study. The capillary flow controller displayed a lower level of variability (RSD: 5.2%) than the diaphragm flow controller (RSD: 8.0%) with respect to flow rate, while allowing for longer durations of sampling. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Environmental Monitoring Occupational Health Safety Temperature Volatile Organic Compounds
• Keywords:
  Air Contaminants Air Sampling Equipment Author Keywords: Air Sampling Bias Capillary Flow Controller Diaphragm Flow Controller Diffusive Sampling Exposure Assessment Sampling Methods Sensitivity Temperature Effects VOCs Volatile Organic Compounds

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• ISSN:
  1545-9624
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  New York ; OSHA Region 2 ; OSHA Region 3 ; OSHA Region 6 ; Texas ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  RHD - Respiratory Health Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  21
• Issue:
  7
• NIOSHTIC Number:
  nn:20069859
• Citation:
  J Occup Environ Hyg 2024 Jul; 21(7):504-514
• Contact Point Address:
  Alan Rossner, Institute for a Sustainable Environment, Clarkson University, Potsdam, New York
• Email:
  arossner@clarkson.edu
• Federal Fiscal Year:
  2024
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0c80b90cc00907dea71f6e2edd45166c655ea043e611652e806ab2de3333ce7b87c940eea592d2700fbc0a936096624d080254fad95cb6d454991492a0c5bb25
• Download URL:
  https://stacks.cdc.gov/view/cdc/208199/cdc_208199_DS1.pdf
• File Type:
  [PDF - 1.41 MB ]