In-Depth Survey Report: Containment Assessment of Nanomaterial Handling Enclosures at Academic Research Laboratories Using Carbon Nanotubes and Graphene

Details

• Personal Author:
  Dunn, Kevin H. ; Ellenbecker, Michael J. ; Lo, Li-Ming ; Tsai, Candace S. J.
• Corporate Authors:
  National Institute for Occupational Safety and Health. Division of Applied Research and Technology
• Description:
  The NIOSH Control Technology Team and the Environmental Health and Safety Team of the University of Massachusetts Lowell (UMass Lowell) conducted an in-depth survey to assess nanoparticle emissions in a chemical laboratory at an academic institution in Boston, Massachusetts. The surveyed laboratory conducted lab scale research using carbon nanotubes (CNTs), neodymium oxide and graphene. The tasks evaluated in this study included weighing and mixing. All tasks were conducted in ventilated nanomaterial handling enclosures similar to pharmaceutical balance enclosures. The research team used direct-reading instruments to monitor the tasks and collected filter samples to characterize released nanomaterials by microscopy and chemical analysis. In addition, performance data on the nanomaterial handling enclosures were collected including face velocity and exhaust filter efficiency. The study results of nanoparticle emissions from this bench-top laboratory scale research evaluation provide information on exposure potential and control effectiveness for these common processes. Overall, minimal exposure potential was identified during the tasks evaluated at these laboratories. This is more likely a result of the small quantities used and good handling techniques than the enclosure performance itself. The real-time monitoring did not identify noticeable particle emissions from the tasks evaluated. All of the elemental carbon (EC) concentrations obtained from filter samples in this study were either below the limit of detection (LOD) or between the LOD and limit of quantitation (LOQ). Although transmission electron microscopy (TEM) analyses identified a few CNTs outside of the ventilated enclosure, the overall concentrations were low. The highest concentration of airborne CNTs were identified during the weigh-out of CNT carpet sample coupons. This task was performed with the enclosure fan turned off to minimize disturbance to material during weigh-out. Average face velocities of the nanomaterial handling enclosures assessed in the three laboratories ranged from 0.21-0.36 meters/second (m/s). Based on the current laboratory fume hood guidance, it would be prudent to increase the overall air flow rates to maintain each of these enclosures to the 0.41-0.51 m/s range for average face velocity. The proper use of personal protective equipment including lab coats, safety glasses and gloves should provide adequate dermal and respiratory protection. Currently, there are few published occupational exposure limits (other than the NIOSH REL of 1 microg/m3) for carbon nanotubes. However, it is good occupational safety and health practice to maintain exposures to new and uncharacterized materials as low as possibly achievable.
• Subjects:
  Air Movements Air Pollutants, Occupational Chemistry Engineering Laboratories Microbiology Occupational Exposure Occupational Health Particulate Matter Personal Protective Equipment Safety Ventilation Workplace

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• Keywords:
  Academic Laboratory Air-filters Airborne-particles Air Flow Carbon Nanotubes Chemical Analysis Control-technology Direct-reading Methods Electron Microscopy Employee Exposure Engineering-controls Engineering Controls Exhaust-hoods Exposure Assessment Filters Fume Hoods Graphene Laboratory Work Laboratory Workers Manual Materials Handling Microscopic Analysis Nanomaterial Handling Enclosure Nanomaterials Nanoparticles Nanotechnology OSHA Region 1 Oxides Particulates Personal Protective Equipment Sampling Task Performance Ventilation-hoods Work-environment

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• Series:
  Engineering and Physical Hazards Survey Reports
• DOI:
  https://doi.org/10.26616/NIOSHEPHB36412a
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Genre:
  Field Study
• Place as Subject:
  Massachusetts ; Boston (MA) ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology ; EPHB - Engineering and Physical Hazards Branch
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-45
• NIOSHTIC Number:
  nn:20048779
• NTIS Accession Number:
  PB2017-100465
• 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 364-12a, 2015 Nov ; :1-45
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6) ; Graphene (CAS RN 1034343-98-0) ; Neodymium sesquioxide (CAS RN 1313-97-9) ; Carbon (CAS RN 7440-44-0)
• Federal Fiscal Year:
  2016
• Peer Reviewed:
  False
• NAICS and SIC Codes:
  611310 - Colleges, Universities, and Professional Schools - (NAICS)
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e4fa7f7a0e95179250ba02f776940cd6e90ee3af893f7fb3b6f1e4e73e5d091e7bdcf713f2b727b072d67ae98404459c368df0f63fcb9c0b5159e611c3e13927
• Download URL:
  https://stacks.cdc.gov/view/cdc/175020/cdc_175020_DS1.pdf
• File Type:
  [PDF - 2.78 MB ]