Slow Curing of Aliphatic Polyisocyanate Paints in Automotive Refinishing: A Potential Source for Skin Exposure

Details

• Personal Author:
  Bello D ; Ibrahim K ; Liu Y ; Redlich CA ; Sparer, Judith ; Stowe MH
• Description:
  Two-component, polyurethane paints containing aliphatic isocyanates are widely used in autobody spray painting. Such isocyanates can cause asthma, and skin exposure may be an important route of sensitization and may contribute to the development of isocyanate asthma. Autobody workers are frequently in contact with recently painted, dried auto parts. It is not known how fast the newly painted car surfaces are fully cured, that is, for how long unbound, isocyanate species remain on painted surfaces after initial drying. To address this question, scrap sections of auto bodies were painted and dried by autobody shop painters following regular practice. Routinely used paints were sprayed 23 different times on the parts. Drying was accomplished by baking the part in a paint spray booth by heating it with a heat lamp or air drying in the shop. The 23 sprayed surfaces were sampled at regular time intervals after drying to determine the presence of free NCO groups using the semiquantitative SWYPE technique. Quantitative isocyanate analysis was also performed on two sprayed parts using NIOSH method 5525. Geometric mean curing time of 23 painted surfaces was 56.4 hr (range: 0.8 hrs to 32 days). Unbound isocyanate species of similar composition to the original bulk material remained present on the majority of sampled painted surfaces for up to 120 hours for typical paint formulations and for 1 month for others. The actual curing of polyurethane paints in autobody refinishing can be a slow process. Unbound isocyanates may remain on the surface of painted car parts for prolonged periods (days to weeks) after dried. Such surfaces are an under-recognized potential source of skin exposure to autobody workers. [Description provided by NIOSH]
• Subjects:
  Automobiles Isocyanates Occupational Exposure Occupational Health Paint Safety Skin
• Keywords:
  Author Keywords: Autobody Shop Automobile Repair Shops Dermal Exposure Hexamethylene Diisocyanate Isocyanate Occupational Exposure Paints Paint Spraying Skin Skin Exposure Spraying Equipment Spray Paint Spray Painting

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Connecticut ; Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  406-411
• Volume:
  4
• Issue:
  6
• NIOSHTIC Number:
  nn:20060625
• Citation:
  J Occup Environ Hyg 2007 Jun; 4(6):406-411
• Contact Point Address:
  Dhimiter Bello, University of Massachusetts Lowell, Department of Work Environment, Kitson Hall, Room 200 (UML North), 1 University Ave., Lowell, MA 01854
• Email:
  dhimiter_bello@uml.edu
• Federal Fiscal Year:
  2007
• Performing Organization:
  Yale University, New Haven, Connecticut
• Peer Reviewed:
  True
• Start Date:
  20020930
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20060929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c2e45faf8512cd85d0c7629b4620ae095a313a8f4b6ff3d1ebb138c1be9d4afa0a5cfd8f6afed9982713a195a23553b104f5e74da30106defb738b70b7b27196
• Download URL:
  https://stacks.cdc.gov/view/cdc/224477/cdc_224477_DS1.pdf
• File Type:
  [PDF - 472.31 KB ]