During the conduction of the Rock Springs Site 9 experiment a large volume of retort water was collected to support environmental research studies. This sample was designated Omega-9 retort water. The Omega-9 water has the following characteristics: pH 8.6, 1003 mg/1 total organic carbon, and 30,300 mg/1 of total dissolved solids which are principally bicarbonate, sodium, ammonium, thiosulfate, sulfate, chloride, and carbonate. Although the Omega-9 water cannot be ascribed as typical of in situ oil shale retort waters in general, its availability has supported numerous investigations into the treatment, disposal, use, and effects of such water. It is reported that consumption of undiluted Omega-9 water by 60 to 80 g Holtzman rats led to an increased rate of metabolism of hexobarbital in vivo and in vitro, an increased rate of metabolism of ethylmorphine in vitro, and an increased level of cytochrome P-450 activity. These observations indicated that Omega-9 water induced liver enzymes activity. The purpose of this study was to determine if the induction effect is concentration related.