The occupational life cycle of MWCNT: toxicity evaluation from as-produced to post-production modifications and composites

Details

• Personal Author:
  Battelli L ; Bishop LM ; Bunker K ; Casuccio G ; Cena L ; Dahm, Matthew M. ; Erdely A ; Eye T ; Kang J ; Kodali V ; Mercer RR ; Orandle M ; Sager T ; Sargent L ; Scabilloni J ; Schubauer-Berigan, Mary K. ; Schwegler-Berry D ; Stefaniak, Aleksandr B. ; Zeidler-Erdely PC ; Battelli L ; Bishop LM ; Bunker K ; Casuccio G ; Cena L ; Dahm, Matthew M. ; Erdely A ; Eye T ; Kang J ; Kodali V ; Mercer RR ; Orandle M ; Sager T ; Sargent L ; Scabilloni J ; Schubauer-Berigan, Mary K. ; Schwegler-Berry D ; Stefaniak, Aleksandr B. ; Zeidler-Erdely PC
• Description:
  Companies synthesize or purchase as-produced multi-walled carbon nanotubes (AP-MW), apply a polymer coating (PC-MW), then embed the PC-MW into an epoxy or fiberglass matrix. Workers are potentially exposed at each production stage from dry powder handling of the MW or aerosols from sanded composites. To date, toxicity studies have focused primarily on AP-MW. The aim was to characterize the toxicity of these additional materials. Materials were prepared to emulate workers personal breathing zone collections and male C57BL/6J mice were then dosed by oropharyngeal aspiration with vehicle, AP-MW, or PC-MW from two separate companies at 4 microg or 40 microg. Mice were sacrificed at 4 h, 1, 7, 28 and 84 d post-exposure with collection of lavage fluid, lung, tracheobronchial lymph node (TBL), kidney, and liver. Both AP-MW induced dose- and time-dependent measures of pulmonary cytotoxicity, inflammatory cell influx, and inflammatory proteins. Histopathology identified small granulomas at terminal bronchioles at 84 d but no significant alveolar fibrosis at the 40 microg dose. In neither case did PC-MW enhance the effects of AP-MW. With mass as a dose metric, inflammation was less from exposure to PC-MW from company #2 and, at 84 d, remaining material was localized to large extracellular aggregates with minimal or no inflammation. All MW were mostly cleared by 84 d. Translocation to the TBL was more prevalent for materials from company #2 but unlike larger diameter MW, no translocation to systemic organs was detected for any material. Lastly, the PC-MW containing composites with 0.15% and 3% PC-MW by weight were subjected to an industrial sanding process. Assessment of generated aerosols show primarily micron size particles with some MW protrusions (evidence of free MW under evaluation). These findings provide toxicity context at different stages of the MW production chain. [Description provided by NIOSH]
• Subjects:
  Aerosols Cells, Cultured Cytotoxins Environmental Exposure Epoxy Resins Glass Hazardous Substances Immune System Laboratories Lung Lymphatic System Manufacturing And Industrial Facilities Occupational Health Polymers Respiratory System Safety Toxicology

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• Keywords:
  Analytical Processes Breathing Zone Cell Cultures Cell Culture Techniques Cellular Effects Coatings Cytotoxicity Epoxy Compounds Exposure Assessment Exposure Levels Fibrous Glass Histopathology Immune Reaction Industrial Engineering Industrial Processes Kidneys Laboratory Animals Laboratory Testing Liver Lung Cells Lymph Nodes Materials Handling Materials Testing Multi-walled Carbon Nanotubes MWCNT Proteins Pulmonary Disorders Toxic Effects Toxic Materials

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary ; Abstract or Summary
• Place as Subject:
  Louisiana ; Ohio ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 6 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies ; RHD - Respiratory Health Division ; HELD - Health Effects Laboratory Division ; DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies ; RHD - Respiratory Health Division
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Volume:
  150
• Issue:
  1
• NIOSHTIC Number:
  nn:20047818
• Citation:
  Toxicologist 2016 Mar; 150(1):584
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6) ; Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2016
• NORA Priority Area:
  Manufacturing ; Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 55th Annual Meeting and ToxExpo, March 13-17, 2016, New Orleans, Louisiana
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:84421e8c055d4231516e47c76c1eef20e2e29137e291bfac4db0779c83e6d9a8b27b649f82a19ef67f0b15873ddf38b60ba0e8eb07cd1adcc94f64a02a2f87fc
• Download URL:
  https://stacks.cdc.gov/view/cdc/202787/cdc_202787_DS1.pdf
• File Type:
  [PDF - 442.22 KB ]