Four laboratory leaching methods (the Environmental Protection Agency (EPA) extraction procedure, ASTM method D3987, and two column tests) were used to extract leachates from four low-void retorted oil shales to (1) compare the leaching procedures based on the chemical characterization of leachates derived from each leaching method and (2) establish the toxicity of each leachate relative to published EPA water quality criteria. The EPA extraction procedure extracted the greatest concentration of trace elements of the methods tested. None of the concentrations of the seven metals (arsenic, barium, cadmium, chromium, lead, selenium, and silver) selected from those listed in the Resource Conservation and Recovery Act (RCRA) exceeded the RCRA limits defining a hazardous waste. On that basis, the low-void retorted oil shales would not be classified as hazardous. 32 refs., 15 figs., 11 tabs.