Characterization of Particles Generated by a Novel Powder Flame Thermal Spray Coating System

Details

• Personal Author:
  Afshari, Aliakbar A. ; McKinney, Walter G. ; Cumpston, Jared L. ; Leonard, Howard D. ; Cumpston, James B. ; Friend, Sherri A. ; Kodali, Vamsi K. ; Meighan, Terence G. ; Lee, E. ; Antonini, James M.
• Description:
  Background and Purpose: Flame Thermal spray coating (FTSC) is a process where a mixture of metal and ceramic coating powder is melted at high temperatures and sprayed onto a surface using air pressure. This creates a complex aerosol containing various elements, such as copper, chromium, nickel, zinc, and aluminum. However, there is limited information available about the health effects associated with exposure to these aerosols. Additionally, the chemical and physical properties of these aerosols are not well understood. To address this gap in knowledge, our goal was to develop an automated FTSC aerosol generator and inhalation exposure system that could simulate workplace exposures. Methods: The system we developed was divided into two areas: (A) an enclosed room with a closed spray booth for the coating process, and (B) an exposure chamber equipped with particle characterization devices. We examined the physicochemical properties of aerosols generated during FTSC using four popular coating powders: F-316HCR-PL10, N-610-FS1, F-S420-PL2, and N-C276-FS2. The coating process was carried out continuously for 2 hours within the spray booth, with the metal feedstock pipe rotating in a circular and up-and-down motion. The spray gun was controlled by computer software and fired at programmed 1-sec intervals for up 12 to 16 sprays during the testing period. Results: During the 2-hour testing period, we were able to achieve and maintain a targeted concentration of 8 mg/m3 in the exposure chamber. We also ensured minimal fluctuations in relative humidity, temperature, and CO2 levels. This allowed us to generate continuous powder spray coating aerosols at a desired concentration for extended periods without interruption. Generated particles were arranged as chain-like agglomerates similar in metal profile to the composition of the consumable coating powder. Conclusions: This system will be valuable for future animal exposure studies aimed at understanding the potential health risks associated with FTSC aerosols. Description provided by NIOSH
• Subjects:
  • Occupational Health
  • Particulate Matter
  • Safety
• Keywords:
  • Aerosols; Inhalation; Coatings; Spraying equipment; Sprays; Aerosol generators
• Source:
  Toxicologist 2025 Mar; 204(S1):257
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Philadelphia Region OSHA ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; RHD - Respiratory Health Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  2 pdf pages
• Volume:
  204
• NIOSHTIC Number:
  nn:20071581
• Federal Fiscal Year:
  2025
• NORA Priority Area:
  Manufacturing ; Services
• Peer Reviewed:
  False
• Download URL:
  https://stacks.cdc.gov/view/cdc/259356/cdc_259356_DS1.pdf
• File Type:
  [PDF - 257.19 KB]
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6ea13e5197263f585db4e71554389435e721b21f1c83d58ab21e30e3ac922f96624cd50c0b9591e675b328a1e8eb7f35ecae7f9e875f126e6c57e05476e52ec8