Repeated Dose Dermal Toxicity: 21/28-Day Study (OECD TG 410)

Abstract

842. This assay determines the subchronic dermal toxicity of chemicals after initial information on toxicity has been obtained by acute testing. It provides information on possible health hazards likely to arise from repeated exposure by the dermal route over a limited period of time. Dosing duration is 28 days and the preferred species are the adult rat, rabbit or guinea pig. Test substance is applied to the dorsal area of the trunk, held in place with a dressing and protected from ingestion. OECD TG 410 was adopted in May 1981. Although it has not been validated for the detection of endocrine active substances (EASs), this assay may contain endpoints that are suitable for the determination of endocrine effects. It should be noted that the only endocrine-relevant tissues that are required are testes and adrenals, therefore the information provided may be very limited. Other tissues may be taken as required and therefore the utility of this assay for detecting EASs will vary on a case-to-case basis. As all the endpoints are apical, it is difficult to discern mechanism of action from this test alone. Information on mechanism of action needs to be obtained from in vitro estrogen/androgen/thyroid/steroidogenesis (E,A,T,S) assays or in vivo lower tier tests such as the Uterotrophic Bioassay (UT – OECD TG 440) and the Hershberger Bioassay (H – OECD TG 441). Hormone measurements are not included in this assay.