EVALUATION OF COAL LIQUIDS DERIVED FROM THE EDS PROCESS IN CARCINOGENESIS SCREENING-TESTS

Four process streams derived from the EDS double dagger direct coal li quefaction process were evaluated in two in vitro assays to screen for carcinogenic potential: the Salmonella/mammalian microsome mutagenici ty assay and the Syrian hamster embryo morphologic transformation assa y, Three high boiling liquids (two recycle solvents, nominal boiling r ange 200-425 degrees C; and a fuel oil blend, nominal boiling range 20 0-538 degrees C) were active in both assays, A hydrotreated naphtha sa mple (<200 degrees C) was not active in either, The Salmonella data ag reed qualitatively with results of dermal carcinogenesis studies; howe ver, quantitative differences as measured by the estimation of mutagen ic potency were apparent. The lack of quantitative agreement may have been related to the fact that the dermal carcinogenic activity of coal -derived synthetic fuels is predominantly associated with neutral poly cyclic aromatic hydrocarbons, whereas activity in the Salmonella assay is strongly influenced by the presence of aromatic amines and nitroar omatic compounds. Two modifications of the Salmonella assay-detergent disperson and hamster S9 activation-were examined, These techniques im proved assay performance for some but not all of the coal liquids, The differences in response may have been related to compositional differ ences in the various liquids.