“…Fisher-Tropsch operations [Heuper, 19531 , and solvent refined coal heavy distillate have all produced tumors in animals under experimental conditions [Battelle, 19791 . Composition data [Oak Ridge National Laboratories, 1975;Battelle Columbus Laboratories, 1974;Swansiger, 1974;Electric Power Research Institute, 1975;ERDA, 19761 suggest that polycyclic aromatic hydrocarbons, heterocyclic compounds and others of carcinogenic potential are likely to be produced in liquefaction processes, primarily in high boiling fractions of product liquids (TRW Systems and Energy, 1976). The total products of hydrogenation, high-boiling distillates, centrifuged oils, chars, residues, recycled solvent oil, recycled solvent and perhaps liquid coal are potentially hazardous [Freudenthal et al, 19751 .…”