Airborne isocyanate exposures in the collision repair industry and a comparison to occupational exposure limits

Details

• Personal Author:
  Ceballos, Diana M. ; Fent, Kenneth W. ; Flack SL ; Nylander-French LA ; Reeb-Whitaker C ; Thomasen JM ; Trelles Gaines LG ; Weiland EC ; Whittaker SG
• Description:
  Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 microg/m3 for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 microg NCO/m3 for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UK-HSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OR-OSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or greater is required to protect against isocyanate exposures during spray painting. Consequently, half-face air-purifying respirators, which are most commonly used and have an assigned protection factor of 10, do not afford adequate respiratory protection. [Description provided by NIOSH]
• Subjects:
  Automobiles Environmental Monitoring Isocyanates Occupational Exposure Occupational Health Paint Personal Protective Equipment Respiratory Protective Devices Safety Workplace
• Keywords:
  Air-purifying-respirators Air-sampling Author Keywords: Autobody Automobile-repair-shops Breathing-zone Coatings Employee-exposure Exposure-assessment Exposure-limits Hexamethylene Diisocyanate Monomers Motor-vehicles Occupational Exposure Limits Permissible-concentration-limits Polyisocyanates Respirators Respiratory-protection Respiratory Protection Short-term-exposure Spray-painting STEL Work-environment

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  North Carolina ; OSHA Region 10 ; OSHA Region 4 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  329-339
• Volume:
  9
• Issue:
  5
• NIOSHTIC Number:
  nn:20040939
• Citation:
  J Occup Environ Hyg 2012 May; 9(5):329-339
• Contact Point Address:
  Carolyn Reeb-Whitaker, Safety & Health Assessment & Research for Prevention (SHARP) Program, Washington State Department of Labor & Industries, 243 Israel Road SE, Bldg. 3, Tumwater, WA 98501
• Email:
  whca235@Lni.wa.gov
• CAS Registry Number:
  Biuret (CAS RN 108-19-0) ; Hexamethylene diisocyanate (CAS RN 822-06-0) ; Isophorone diisocyanate (CAS RN 4098-71-9)
• Federal Fiscal Year:
  2012
• Performing Organization:
  University of North Carolina, Chapel Hill, North Carolina
• Peer Reviewed:
  True
• Start Date:
  20030801
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20070731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:202978a407b616248623a568b21687ae121d0d6989d242eedf734c34d3b0bd4752a70ba5065465ffad7526b19fedba7fc03f847ba1f2cbaa417238a33087a8c4
• Download URL:
  https://stacks.cdc.gov/view/cdc/193630/cdc_193630_DS1.pdf
• File Type:
  [PDF - 316.68 KB ]