Sediment-Water Chironomid Life-Cycle Toxicity Test (OECD TG 233)

452. Modality detected/endpoints: This long-term in vivo assay with the dipteran insect Chironomus spp. is responsive to juvenile hormone (JH) (ant)agonists and ecdysteroid (Ec) (ant)agonists which can interfere with such processes as metamorphosis, moulting, growth and reproduction. It exposes the test organisms over two generations. It is important to note, however, that none of the endpoints in this apical test are specifically responsive to JHor Ec-active chemicals, and the assay will give positive results with many other substances. The lack of internationally validated mechanistic assays for endocrine activity in insects may prevent firm conclusions about whether test chemicals are endocrine dusruptors (EDs) in this taxon, although in vitro assays for JH and Ec activity are available in the literature. However, the data from the test may nevertheless be of value for classification and hazard identification/characterisation.