The objective of this study was to evaluate the oncogenic potential of test materials MRD-82-18, MRD-82-57A, MRD-82-142, and MRD-82-153 through MRD-82-157, MRD-82-19A, MRD-82-19A, and MRD-82-19C when applied to mouse skin. The study was initiated with 510 male C3H/HeJ mice which were divided into 9 groups of 50 mice each and 3 groups of 20 mice each. The animals of Groups 1 through 11, and 14 through 16 received 25 micro liters of undiluted test material to the clipped backs 3 times per week until death of the animals; Group 13 served as a shaved control which did not received any test material but was assigned test material number MRD-82-158, and Group 12 served as the negative control receiving 25 microliters of MRD-82-157. (All statistical analyses were run against Group 12, the control group).