Alternative methods to animal experiments. What can they afford in the safety testing of chemical substances under REACH?

Alternative methods to safety studies using laboratory animals have been accepted by the OECD in areas such as local toxicity and mutagenicity. In more complex important fields, such as systemic single and repeated dose toxicity, toxicokinetics, sensitisation, reproductive toxicity and carcinogenicity, it is expected that the development and validation of computerised methods, testing batteries (in vitro and in silico) and tiered testing systems will need many years and have to overcome many scientific and regulatory obstacles, which makes it extremely difficult to predict the outcome and the time needed. Therefore, the validated alternative methods available will only have a limited impact on reducing the numbers of animals required under REACH. In the midterm, the strategy should be more directed towards the refinement or reduction of in vivo testing because the replacement concerning complex toxicological endpoints is at present not in sight.