Incineration tests were conducted at The Marquardt Company, Van Nuys, California, to determine the effectiveness of thermally destroying two selected industrial liquid wastes: ethylene manufacturing waste and hexachlorocylopentadiene (C-5,6). Each waste was burned at three different test conditions to determine the effects of normal operating and equipment variables. Analysis of combustion gas samples indicated destruction efficiencies of over 99.999 percent for each waste constituent. Standard EPA Method 5 tests were performed on stack emissions to determine particulate loading and composition. Analysis of scrubber water samples indicated no increase in organic content compared to fresh scrubber water. Burner head residue formed during incineration of each waste contained no chlorinated organics. Results of these tests indicated that either waste can be effectively destructed in a liquid injection incinerator; however, because of tarry residual, the C-5,6 waste may be better matched to rotary kiln incineration. Estimated cost of destroying an assumed annual production of 15 million kilograms of ethylene waste was $1.8 million capital investment and $1.0 million annual operating costs ($69/metric ton). Cost of incinerating 4.5 million kilograms of C-5,6 per year was estimated to be $1.6 million capital investment and $2.2 million annual operating costs ($488/metric ton).