Read-across – predicting unknown properties of one chemical from known properties of similar chemicals – is a scientific method for filling data gaps on the effects of chemicals.
The aim of the Read-Across Assessment Framework (RAAF) is to provide a structured approach to the scientific evaluation of read-across justifications made by registrants in their dossiers. The first publication covers read-across of human health endpoints for monostituent substances. ECHA will use it to make sure that read-across cases for human health endpoints are assessed consistently during dossier evaluation.
Registrants can use the RAAF to see the aspects of read-across justifications that ECHA considers to be crucial. This should help them to assess the quality of their own read-across cases. The RAAF is going to be further developed to also cover environmental endpoints next year.
"This is the first time that we are explaining how we evaluate read-across cases. It will help registrants to anticipate how we are going to assess their cases and thereby enable them to improve their dossiers. Of course, given the scientific complexity of the issue, this is not easy reading, but the scientists preparing read-across justifications will find it invaluable," says Geert Dancet, ECHA's Executive Director.
Read-across is the most commonly used alternative approach to filling data gaps on the effects of chemicals on humans and the environment where the test prescribed by REACH requires testing on animals. It can therefore help to avoid unnecessary testing on vertebrate animals. It works by using test results of a particular property of a substance from analogous substances to predict that property for the target substance.