Reducing silica and dust exposures in construction during use of powered concrete-cutting hand tools: efficacy of local exhaust ventilation on hammer drills

Details

• Personal Author:
  Ellenbecker M ; Holcroft C ; Shepard S ; Woskie S
• Description:
  Concrete cutting in construction is a major source of exposure to respirable crystalline silica. To reduce exposures, local exhaust ventilation (LEV) may be integrated into the hand tools used in order to collect the dust at its source. The research team conducted a fi eld study at the New England Laborers Training Center to establish the efficacy of various LEV systems at this task. The study evaluated two drill bit hoods (a bellows that fits over the drill bit, and a ring hood designed to cover the point where the bit addresses the surface) and two vacuum sources (a smaller HEPA filtered shopvac (Porter-Cable) and a larger, more powerful device (Dust Control). Researchers collected samples from personal air monitors (4-stage impactors) while four apprentices drilled holes in a concrete wall employing each of the four possible combinations of hood and vacuum, plus drilling without LEV, resulting in 15 respirable dust and quartz sample for comparison. With no LEV, the task generated 308 micrograms of respirable silica dust per cubic meter of air (308ug /m3), a level widely recognized as hazardous. The bellows hood and shop-vac combination reduced airborne silica levels by 98% in the round of trials. All of the control combinations reduced respirable airborne silica levels by at least 91% (average 94%). All of the control combinations reduced respirable airborne silica levels well below 50 micrograms of silica per cubic meter of air (50ug /m3), the new Permissible Exposure Limit (PEL) proposed by OSHA (12-28 ug/m3). [Description provided by NIOSH]
• Subjects:
  Aluminum Silicates Construction Industry Dust Environmental Monitoring Occupational Health Quartz Risk Assessment Risk Factors Safety Silicon Dioxide Ventilation

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• Keywords:
  Air-monitoring Concretes Construction Construction-industry Dust-exposure Dust-particles Dusts Exposure-levels Hand-tools Monitors Quartz-dust Risk-factors Silicates Vacuum-equipment

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• Publisher:
  CPWR-The Center for Construction Research and Training
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Report
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OD - Office of the Director
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1
• NIOSHTIC Number:
  nn:20046800
• Citation:
  Silver Spring, MD: CPWR-The Center for Construction Research and Training, 2014 Jun; :1
• Email:
  Susan_Woskie@uml.edu
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7) ; Silica (CAS RN 7631-86-9)
• Federal Fiscal Year:
  2014
• NORA Priority Area:
  Construction
• Performing Organization:
  CPWR - The Center for Construction Research and Training, Silver Spring, Maryland
• Peer Reviewed:
  False
• Start Date:
  20090901
• Source Full Name:
  Reducing silica and dust exposures in construction during use of powered concrete-cutting hand tools: efficacy of local exhaust ventilation on hammer drills
• End Date:
  20240831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e36cf07d6d5f06322a90d5056feba2cf78b7c04ff7d6ad19752f18f03a4913cce22442461b3432b752e7ad426a8ab5349077fd1fc4bbb6e1a7fce7a8f4664a51
• Download URL:
  https://stacks.cdc.gov/view/cdc/202109/cdc_202109_DS1.pdf
• File Type:
  [PDF - 42.12 KB ]