INTRODUCTION The objective of this study was to determine the toxicity of a selected petroleum-derived hydrocarbon@ API 83-06@ when administered to rabbits over a 4-week period by dermal application. Dosing was initiated on July 23@ 1984 and was completed on August 21@ 1984. All animals were terminated by August 24@ 1984. This study was run concurrently with two companion studies assessing two additional API compounds. These studies are .reported separately as TLI projects 17100(2) and 17100(3). Each of the companion studies had its own control group and three treated groups. A pilot five-day dermal study in rabbits (Phase I) was performed in order to determine the dose levels to be used during this study (Phase I I ) . Phase I dosing was initiated on June 11@ 1984 and was completed on June 15@ 1984. Terminal sacrifice occurred on June 22@ 1984. The report of the Phase I study is presented in Addendum I of this report.