Effect of Hollow Bit Local Exhaust Ventilation on Respirable Quartz Dust Concentrations During Concrete Drilling

Details

• Personal Author:
  Barr A ; Cooper MR ; Rempel D
• Description:
  Drilling large holes (e.g., 10-20mm diameter) into concrete for structural upgrades to buildings, highways, bridges, and airport runways can produce concentrations of respirable silica dust well above the ACGIHVR Threshold Limit Value (TLVVR = 0.025 mg/m3). The aim of this study was to evaluate a new method of local exhaust ventilation, hollow bit dust extraction, and compare it to a standard shroud local exhaust ventilation and to no local exhaust ventilation. A test bench system was used to drill 19mm diameter x 100mm depth holes every minute for one hour under three test conditions: no local exhaust ventilation, shroud local exhaust ventilation, and hollow bit local exhaust ventilation. There were two trials for each condition. Respirable dust sampling equipment was placed on a "sampling" mannequin fixed behind the drill and analysis followed ISO and NIOSH methods. Without local exhaust ventilation, mean respirable dust concentration was 3.32 (+/- 0.65) mg/m3 with a quartz concentration of 16.8% by weight and respirable quartz dust concentration was 0.55 (+/- 0.05) mg/m3; 22 times the ACGIH TLV. For both LEV conditions, respirable dust concentrations were below the limits of detection. Applying the 16.8% quartz value, respirable quartz concentrations for both local exhaust ventilation conditions were below 0.007mg/m3. There was no difference in respirable quartz dust concentrations between the hollow bit and the shroud local exhaust ventilation systems; both were below the limits of detection and well below the ACGIH TLV. Contractors should consider using either local exhaust ventilation method for controlling respirable silica dust while drilling into concrete. [Description provided by NIOSH]
• Subjects:
  Dust Environmental Exposure Occupational Health Quartz Respiratory System Risk Assessment Risk Factors Safety Silicon Dioxide Ventilation
• Keywords:
  Author Keywords: Concrete Concretes Drilling Dust Exposure Dusts Equipment Design Exhaust Ventilation Exposure Control Exposure Levels Masonry Quartz Dust Respiratory Irritants Risk Factors Silica Silica Dusts Threshold Limit Values TLV Tool Design Tools

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  336-340
• Volume:
  16
• Issue:
  5
• NIOSHTIC Number:
  nn:20055558
• Citation:
  J Occup Environ Hyg 2019 May; 16(5):336-340
• Contact Point Address:
  David Rempel, Department of Bioengineering, University of California, Berkeley, 1301 S. 46th Street, Building 163, Richmond, 94804
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7) ; Silica (CAS RN 7631-86-9)
• Federal Fiscal Year:
  2019
• Performing Organization:
  CPWR - The Center for Construction Research and Training, Silver Spring, Maryland
• Peer Reviewed:
  True
• Start Date:
  20090901
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20240831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8fb3bfb1118f89f6d54dae3ddd970afe1d04850d3d36f4e17569b9850ec1a53eb923f1626935bf2e9b47eba74737692e321211e916d2dcd2fa6d4acb60ba09c8
• Download URL:
  https://stacks.cdc.gov/view/cdc/213383/cdc_213383_DS1.pdf
• File Type:
  [PDF - 868.73 KB ]