Update to OECD Guidance Document 23 on Aqueous-Phase Aquatic Toxicity Testing of Difficult Test Chemicals

The Organisation for Economic Co-operation and Development (OECD) has published an update to Guidance Document 23 on Aqueous-Phase Aquatic Toxicity Testing of Difficult Test Chemicals, which includes more information on testing poorly water-soluble substances without using solvents. These updates will reduce the number of occasions when solvents (and consequently the solvent control) are required and therefore help reduce the number of animals used in aquatic toxicity studies. Improved guidance will also reduce the need to repeat studies. The Consortium, as a member of the International Council for Animal Protection in OECD Programmes, initiated this effort, which was led by the European Commission and the US Food and Drug Administration and contributed to by a broad variety of stakeholders, including regulators and industry representatives.