The study examines the toxic and teratogenic effects of purified 2,3,4,6-tetrachlorophenol (TCP) administered by gavage to timed-pregnant CD rats during the period of major organogenesis, i.e., gestational days (gd) 6 through 15. The study is designed to examine the potential effects of the test compound upon maternal status, as well as the growth, viability and morphological development of the fetus. The test species, doses for the teratology study (0, 25, 100 and 200 mg/kg/day), route of administration, vehicle and dose volume have been selected by the sponsor based upon pre-existing toxicity data obtained from the available scientific literature and other unpublished studies recently conducted by the sponsor. The high dose selected for the teratology investigation is expected to produce significant evidence of maternal and/or fetal toxicity while allowing survival of at least 90% of treated females through scheduled sacrifice (gd 20).