BIOLOGICAL MONITORING OF OCCUPATIONAL EXPOSURE TO TOLUENE DIISOCYANATE

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