Workers exposed to thermal degradation products of TDI-and MDI-based polyurethane : Biomonitoring of 2,4-TDA, 2,6-TDA, and 4,4'-MDA in hydrolyzed urine and plasma.
The aim of the study was to investigate biomarkers of exposure to thermal degradation products of 2,4-and 2,6-toluene diisocyanate (TDI) - and 4,4'-methylenediphenyl diisocyanate (MDI) - based polyurethane and the toxicokinetics of these products.
Blood and urine were collected from 15 factory workers exposed to thermal degradation products of MDI-based polyurethane glue and TDI-based flexible foam.
Four of these workers were also studied during an exposure-free period.
Urine and plasma were analyzed after acidic hydrolysis and the concentrations of the isocyanates'corresponding amines, 2,4-2,6-toluenediamine (TDA), and 4,4-imethylenedianiline (MDA), were determined as derivatives of pentafluoropropionic anhydride by gas chromatography using chemical ionization mass spectrometry monitoring negative ions.
Urinary elimination rates were in the range of<0.01-5.7 mug of 2,4-TDA per hour,<0.01-3.5 mug of 2,6-TDA per hour, and<0.01-1.6 mug of 4,4'-MDA per hour.
Plasma levels were in the range of<0.1-5.5 ng of 2,4-TDA per mL,<0.1-2.3 ng of 2,6-TDA per mL, and<0.1-45 ng of 4,4'-MDA per mlThe urinary half-lives of 4,4'-MDA for four of the workers were found to be 59,61,73, and 82 hours.
The half-lives of 4,4'-MDA in plasma were 10,14,16, and 22 days.
Elimination rate peaks of 2,4-TDA, 2,6-TDA, in4 4,4'-MDA in urine varied during and between workdays. (...)
Mots-clés Pascal : Uréthanne polymère, Industrie chimique, Exposition professionnelle, Médecine travail, Homme, Dégradation thermique, Produit dégradation, Surveillance biologique, Liquide biologique, Métabolite, Urine, Plasma sanguin, Sang, Toluène(diisocyanato), Diphénylméthane(4,4p-diisocyanato)
Mots-clés Pascal anglais : Polyurethane, Chemical industry, Occupational exposure, Occupational medicine, Human, Thermal degradation, Degradation product, Biological monitoring, Biological fluid, Metabolite, Urine, Blood plasma, Blood
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0476285
Code Inist : 002B03L06. Création : 03/02/1998.