Selecting processes to minimize hexavalent chromium from stainless steel welding

Details

• Personal Author:
  Antonini J ; Chen B ; Cumpston A ; Keane M ; Siert A ; Slaven, James E. ; Stone S
• Description:
  Eight welding processes/shielding gas combinations were assessed for generation of hexavalent chromium (Cr6+) in stainless steel welding fumes. The processes examined were gas metal arc welding (GMAW) (axial spray, short circuit, and pulsed spray modes), flux cored arc welding (FCAW), and shielded metal arc welding (SMAW). The Cr6+ fractions were measured in the fumes; fume generation rates, Cr6+ generation rates, and Cr6+ generation rates per unit mass of welding wire were determined. A limited controlled comparison study was done in a welding shop including SMAW, FCAW, and three GMAW methods. The processes studied were compared for costs, including relative labor costs. Results indicate the Cr6+ in the fume varied widely, from a low of 2800 to a high of 34,000 ppm. Generation rates of Cr6+ ranged from 69 to 7800 ug/min, and Cr6+ generation rates per unit of wire ranged from 1 to 270 ug/g. The results of field study were similar to the findings in the laboratory. The Cr6+ (ppm) in the fume did not necessarily correlate with the Cr6+ generation rate. Physical properties were similar for the processes, with mass median aerodynamic diameters ranging from 250 to 336 nm, while the FCAW and SMAW fumes were larger (360 and 670 nm, respectively). Conclusion: The pulsed axial spray method was the best choice of the processes studied based on minimal fume generation, minimal Cr6+ generation, and cost per weld. This method is usable in any position, has a high metal deposition rate, and is relatively simple to learn and use. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Hot Temperature Metals Occupational Health Safety Welding
• Keywords:
  Analytical-processes Arc-welding Author Keywords: Hexavalent Chromium Stainless Steel Flux Cored Arc Welding (FCAW) Fumes Gas-welders Gases Gas Metal Arc Welding (GMAW) Hazards Heat Heat-exposure Metal-compounds Metal-fumes Metallic-compounds Metallic-fumes Shielded Metal Arc Welding (SMAW) Welders Welding-equipment Welding-industry Welding Fume

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• ISSN:
  0043-2296
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; Indiana ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 8 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  91
• Issue:
  9
• NIOSHTIC Number:
  nn:20041532
• Citation:
  Welding J 2012 Sep; 91(9):241s-246s
• Email:
  mjk3@cdc.gov
• CAS Registry Number:
  Chromium (CAS RN 7440-47-3) ; Chromium(6+) (CAS RN 18540-29-9)
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Construction
• Peer Reviewed:
  False
• Source Full Name:
  Welding Journal
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9b144ab6b87ab40201887eeb1e51e4ccb6b6a5edc96ce657a7a087775e7cdd8fe91780b6fda5c41fd1659d9d05526e4a6ab6005341a2cb561e8a862e4a242df1
• Download URL:
  https://stacks.cdc.gov/view/cdc/194075/cdc_194075_DS1.pdf
• File Type:
  [PDF - 202.73 KB ]