AIR AND BIOLOGICAL MONITORING OF TOLUENE DIISOCYANATE IN A FLEXIBLE FOAM PLANT

Comparative air measurements of toluene diisocyanate (TDI) were perfor med in a 5.6 m(3) standard atmosphere and at a TDI flexible foam plant . Air samples were collected in midget impinger flasks containing 9-(N -methyl-amino-methyl)-anthracene (MAMA) in toluene and on 13-mm glass- fiber filters impregnated with MAMA and glycerol analyzed by LC-UV and with filter-tape instruments. In the laboratory study the average amo unts of the TDI-MAMA derivatives determined were higher for filters co mpared to impingers when tested at concentrations between 16 and 150 m u g/m(3) (n=29). At the TDI foaming plant the amount of TDI-MAMA colle cted on the filters compared with impingers showed higher TDI values a t low concentrations and lower values at higher concentrations . The s ame was seen for the filter-tape measurements, but for two samples at very low concentrations the response was much lower. The average air c oncentration was 29.8 mu g/m(3) (12.5-79.9; n=12). The highest exposur e peak measured was approximately 3 mg TDI/m(3). 2,4- and 2,6-toluene diamine (TDA) in urine (U-TDA) and in plasma (P-TDA) from four exposed workers and one volunteer were determined after strong acid hydrolysi s as their pentafluoro-propionic anhydride derivatives using gas chrom atography-mass spectrometry. The ions monitored were the M-20 ions (M= molecular weight) of the TDA and trideuterium labeled TDA as the inter nal standard. The P-TDA among the workers varied between 1-38 mu g/L a nd between 7-24 mu g/L for 2,4- and 2,6-TDA, respectively. The individ ual plasma levels among the workers over the 3-day periods varied betw een 7-73%. For the volunteer, P-TDA reached a maximum about 24 hours a fter the last exposure. The half-time of P-TDA for the volunteer was a bout 10 days. The urine levels (U-TDA) varied greatly with time and e xposure. High peaks were found during or shortly after the exposure. N o clear correlation between air levels of TDI measured with the filter -tape instruments and levels of TDA in hydrolyzed urine and plasma was seen, but the U-TDA(Max) followed the exposure in time as measured wi th the filter-tape instruments.