Biological monitoring of occupational exposure to toluene diisocyanate

Abstract

The study validated the use of urinary toluene diamine (TDA) in postshift samples as an indicator of preceding 8-h exposure to toluene diisocyanate (TDI). Nine workers exposed in TDI-based polyurethane foam production were studied. Their exposure levels varied in 8-h time-averaged samples from 9.5 to 94 micrograms/m3. The urinary TDA concentrations varied from 6.5 to 31.7 micrograms/g creatinine and they were linearly related to the atmospheric TDI levels. Approximately 20% of TDI is metabolized to diamines but their specificity is remarkable to the extent that by analysis for the 2,4- and 2,6-diamino isomers an idea of the percutaneous absorption may be had.

Biological monitoring of exposure to toluene diisocyanate

“…For diisocyanates, only one biological exposure limit has been established, for 4,4'-methylenediphenyl diisocyanate, for which Germany has applied a BAT of 10 µg/g creatinine, using 4,4'-diaminodiphenylmethane in hydrolyzed urine as the biomarker of exposure. For TDA in hydrolyzed urine as a biomarker for TDI exposure, a BEI of about 20 µg/g creatinine has previously been estimated by Maitre et al (9).…”

“…The blood samples were collected by arm-vein puncture, in Venoject® blood sampling tubes containing heparin. After The median of the urinary biomarker levels is also given in µg/g creatinine to facilitate comparisons with the results of earlier studies (9).…”

“…These earlier studies were performed in only one or two plants, and there were few workers. None of these studies included data on both urinary and blood biomarkers (6,8,9,10).…”

Toluene diisocyanate concentration investigation among TDI-related factories in Taiwan and their relations to the type of industry

“…Maitre et al (1993) reported that the air concentrations in a TDI -based PU foam factory were 9.5 -94 g/m 3 (about 1.3-13 ppb). Lind et al ( 1996 ) reported that the air concentrations of total 2,4 -and 2,6 -TDI in the flexible PU foam production plants were 0.4 -120 g/m 3 (about 0.5-15.0 ppb), compared to 29.8 g/m 3 ( about 4.1 ppb ) in the report of Tinnerberg et al ( 1997 ).…”

Toluylendiisocyanate [MAK Value Documentation in German language, 1999]

“…In anderen Studien betrug der mit dem Urin ausgeschiedene Anteil der Radioaktivität nach Aufnahme von 14 C-TDI abhängig von der Dosis 3,5; 6,3 und 16% (RTI 1988) Stoltz et al 1988;Timchalk et al 1994). Grundsätzlich kann beim Menschen eine TDI-Exposition zumindest qualitativ durch den Nachweis von 2,4-und 2,6-TDA in hydrolysiertem Urin oder hydrolysiertem Plasma nachgewiesen werden Carbonnelle et al 1996;Dalene et al 1994;Lind et al 1996bLind et al , 1997aMaitre et al 1993;Persson et al 1993;Rosenberg und Savolainen 1986;Sandström et al 1989;Skarping et al 1991;Tinnerberg et al 1997 Lind et al 1996aLind et al , 1997aSkarping et al 1991). Die Ausscheidung von TDA mit dem Urin -bestimmt nach saurer Hydrolyse -betrug bei exponierten Probanden insgesamt 8-14% bzw.…”