Friday, 09 January 2015 21:55

ECVAM: Repeated Dose Studies instead of LD50 Tests Featured

They are still being used: animal tests for identification and classification of acute systemic toxicity. And there are not enough replacement methods in sight.

Data for systemic toxicity for regulation of chemicals are still required, whether in REACh, CLP rules (Classification, Labelling and Packaging), according to the biocide or Plant Protection Directive. So far for this endpoint only in vivo tests are accepted. The standard is the LD50 test which is conducted on rodents. Bis this procedure is not only criticized from animal activists but also from a broad community of scientists who regard the tests as questionable and unnecessary.

Finally, there is a whole range of tests that need to be done, such as long-term tests (repeated dose studies on rodents and non-rodent species) with repeated oral administers or exposures through lung and skin. Few substances are produced for a single use, most of them are for a long term, repeated application. What for a test that does not supply sufficient information?

However, in many cases still are missing information on acute toxicity pathways of man and the development mechanistic alternative approaches for these experiments has made little progress.

Therefore, EURL-ECVAM (the EU Reference Laboratory for Alternatives to Animal Testing recommends to collect, organizing and applying mechanistic knowledge related to this endpoint, to provide a strong mechanistic basis  for the design and validation of integrated prediction models. EURL-ECVAM proposes to evaluate promising components of integrated approaches for testing and assessment, including the better use of existing alternative methods, such as mechanistically relevant in vitro assays. Information on repeated dose toxicity might also be useful in supporting classification and labelling for acute systemic toxicity.

For more information: