Manganese Fractionation Using a Sequential Extraction Method to Evaluate Welders’ Flux Core Arc Welding Exposures in a Shipyard, Structural Steel and Custom Parts Manufacturers

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• Personal Author:
  Andrews, Ronnee N. ; Ashley, Kevin E. ; Bertke S ; Carter T ; Hanley, Kevin W. ; Navarro K
• Description:
  The National Institute for Occupational Safety and Health (NIOSH) has conducted an occupational exposure assessment study of manganese (Mn) in flux core arc welding fume at three facilities. The objective of this study was to evaluate exposures to different Mn fractions using a sequential extraction procedure. Sixty-seven worker-days were monitored for either total or respirable Mn. The samples were analyzed using an experimental method to separate four Mn fractions based on chemical solubility: soluble Mn in a mild ammonium acetate solution; Mn0,2+ in 25% acetic acid; Mn3+,4+ in hydroxylamine hydrochloride in 25% acetic acid; and insoluble Mn fractions in hydrochloric/nitric acid. The full-shift total particle size Mn time-weighted average (TWA) breathing zone concentrations ranged from 0.51 to 43; 2.9 to 850; 1.7 to 620; and 0.56 to 331 ug·m-3, for the different Mn fractions, respectively. The summation of all the total particulate Mn fractions yielded results that ranged from 16 to 1,530 ug m-3. The ranges of respirable size Mn TWA concentrations were 0.27 to 75 for soluble Mn; 1.6 to 690 for Mn0,2+; 1.3 to 740 for Mn3+,4+; 0.52 to 570 for insoluble Mn; and 3.8 to 1,800 ug·m-3 for Mn (sum of fractions). Total particulate TWA GM concentrations of the Mn(sum) were 56 (GSD = 4.0), 380 (GSD = 2.7), and 176 (GSD = 3.3) ug·m-3 for the shipyard, structural steel and custom parts facilities. Although most of the workers' exposures measured were below the NIOSH Recommended Exposure Limit for Mn (1,000 ug·m-3), 44 welders' exposures exceeded the ACGIH Threshold Limit Values for total Mn (100 ug·m-3) and 46 exceeded the new respirable Mn TLV (20 ug·m-3). This study shows that a welding fume exposure control and management program is warranted for Mn, which includes improved exhaust ventilation and may necessitate the use of respiratory protection, especially for welding in enclosed or confined spaces. [Description provided by NIOSH]
• Subjects:
  Chemistry Environmental Exposure Hazardous Substances Manganese Occupational Exposure Occupational Health Particulate Matter Respiratory Protective Devices Safety Ventilation Welding

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• Keywords:
  Analytical Methods Arc Welders Arc Welding Chemical Analysis Chemical Extraction Chemical Properties Exposure Assessment Exposure Levels Exposure Limits Hazard Controls Insoluble Compounds Manganese Compounds And Fume Occupational Exposure Particulates Recommended Exposure Limits RELs Respirators Respiratory Protective Equipment Sampling Soluable Compounds Soluble Threshold Limit Values Time Weighted Average Exposure TLV Ventilation Systems Welders Welding Fumes

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• ISSN:
  0949-8036
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Arizona ; Ohio ; OSHA Region 10 ; OSHA Region 5 ; OSHA Region 9 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DFSE - Division of Field Studies and Engineering ; HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  185-193
• Volume:
  80
• Issue:
  5
• NIOSHTIC Number:
  nn:20060422
• Citation:
  Gefahrstoffe - Reinhaltung der Luft 2020 May; 80(5):185-193
• Contact Point Address:
  K. W. Hanley, Division of Field Studies & Engineering, National Institute for Occupational Safety and Health, Cincinnati, OH, United States
• CAS Registry Number:
  Manganese (CAS RN 7439-96-5)
• Federal Fiscal Year:
  2020
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Gefahrstoffe - Reinhaltung der Luft
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:95bfcabbf1b8a5f023e7bdd8f3acd8e26e5154b24a79e9bcf75c699e08e2286aa825a3063839eede41f4733f9a35299fd259615c640a386ace28bba4fb671761
• Download URL:
  https://stacks.cdc.gov/view/cdc/224322/cdc_224322_DS1.pdf
• File Type:
  [PDF - 5.25 MB ]