Details:

• Alternative Title:
  In-Depth Survey Report: Removing Mortar with a Powered Chisel with On-Tool Local Exhaust Ventilation and a Higher-Flow Vacuum Cleaner, International Union of Bricklayers and Allied Craftworkers Southern Ohio-Kentucky Regional Training Center, Batavia
• Personal Author:
  Echt, Alan S. ; Qi, Chaolong

  Echt, Alan S. ; Qi, Chaolong Less -
• Corporate Authors:
  National Institute for Occupational Safety and Health. Division of Applied Research and Technology
• Description:
  Background: Workplace exposure to respirable crystalline silica can cause silicosis, a progressive lung disease marked by scarring and thickening of the lung tissue. Several construction materials (such as brick, block, mortar and concrete) contain crystalline silica. Construction tasks that cut, break, grind, abrade, or drill those materials have been associated with overexposure to dust containing respirable crystalline silica. Tuckpointing (repointing) removes damaged mortar from joints in masonry walls and replaces it with new mortar to restore the wall. The use of grinders to remove mortar results in worker overexposure to respirable crystalline silica. NIOSH scientists are conducting a study to assess respirable crystalline silica exposures associated with mortar removal when tools other than grinders are used. Assessment: NIOSH staff visited the Bricklayers and Allied Craftworkers' Southern Ohio-Kentucky Regional Training Center located in Batavia, Ohio on April 4, 2017, and performed industrial hygiene sampling, which measured exposures to respirable dust and respirable crystalline silica while an experienced bricklayer used a powered chisel with on-tool local exhaust ventilation to remove type N mortar from an indoor brick wall. The NIOSH scientists also observed the work process in order to understand the conditions that contributed to the measured exposure and collected airflow data. Results: Personal breathing zone respirable crystalline silica concentrations measured during 18 to 25-minute-long periods of mortar removal ranged from less than the limit of detection to 0.053 mg/m3. The highest concentration detected was a sample result between the LOD and LOQ, which is considered a trace value with limited confidence in its accuracy. Personal breathing zone respirable dust concentrations collected on filter samples ranged from less than the limit of detection to 0.89 mg/m3. Conclusions and Recommendations: The powered chisel with on-tool local exhaust ventilation tested here produced respirable crystalline exposures less than those reported when grinders were used with local exhaust ventilation under similar test parameters. If this tool can remove mortar with the speed and quality required by contractors and is acceptable to workers, it represents an alternative to the use of grinders. However, if it was used for a full shift and dust levels remained constant, the highest quartz concentration measured during use of the chisel - 0.053 mg/m3 - would be about 1.06 times the OSHA PEL and NIOSH REL, requiring the use of a respirator with an assigned protection factor of 10, such as an N-95 filtering facepiece respirator. Full-shift sampling on job sites should be conducted to validate these findings.
• Subjects:
  [+]

  Air Movements Construction Industry Dust Engineering Environmental Monitoring Manufacturing And Industrial Facilities Occupational Exposure Occupational Health Personal Protective Equipment Quartz Respiratory Protective Devices Safety Silicon Dioxide Ventilation
• Keywords:
  [+]

  Air Flow Air Sampling Breathing Zone Bricklayers Cements Chisels Concretes Construction-equipment Construction Workers Control-technology Crystalline Silica Dust-exposure Dust Control Employee-exposure Engineering-controls Equipment Testing Exhaust Ventilation Exposure-assessment Exposure-levels Exposure-limits Grinding Equipment Industrial Environment Industrial Hygiene Masons N95 Filtering Facepiece Respirators OSHA Region 5 PELs Permissible Exposure Limits Power Tools Quartz-dust Recommended Exposure Limits RELs Respirable-dust Respirators Respiratory Protection Sampling Silica-dusts Tools Vacuum Cleaning Systems Vacuum Equipment Work Practices
• Series:
  Engineering and Physical Hazards Survey Reports
• DOI:
  https://doi.org/10.26616/NIOSHEPHB38112a
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Name as Subject:
  International Union of Bricklayers and Allied Craftworkers
• Genre:
  Field Study
• Place as Subject:
  Ohio ; Batavia (OH) ; OSHA Region 5

  Ohio ; Batavia (OH) ; OSHA Region 5 Less -
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology ; EPHB - Engineering and Physical Hazards Branch

  DART - Division of Applied Research and Technology ; EPHB - Engineering and Physical Hazards Branch Less -
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-19
• NIOSHTIC Number:
  nn:20050913
• Citation:
  Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, EPHB 381-12a, 2018 Jan;:1-19;
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2018
• NORA Priority Area:
  Construction
• Peer Reviewed:
  False
• NAICS and SIC Codes:
  611513 - Apprenticeship Training - (NAICS)
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  [+]

  urn:sha-512:3ee14d2090c091b5e68d21d2e257a8be1298faf6c5fb9a061e9df8716ba3020fa938273058e1b5d4e56e41ff98906ffa865dbbdf65fdc85857b6a08b7deb5977
• Download URL:
  https://stacks.cdc.gov/view/cdc/175039/cdc_175039_DS1.pdf
• File Type:
  [PDF-1.55 MB]