New advice for determining dose levels in toxicity testing

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ECHA has published new advice on choosing the correct substance dose levels for toxicity tests. It helps companies ensure reliable results to conclude on the safety on their chemicals. The clarification comes from the amended REACH annexes which started to apply in January 2022.


Companies need to choose the correct substance dose for their toxicity tests to conclude on the safety of their chemicals. This is clarified in the amended REACH annexes, which apply as of January 2022. ECHA’s advice helps companies ensure reliable results while avoiding repeated animal tests.

The data companies generate from toxicity tests must be adequate for identifying the hazards and assessing the risks of their chemicals. Companies must also prevent severe suffering when carrying out animal tests. Toxicity tests should be done at an appropriately high dose level, in line with the corresponding OECD test guideline. This ensures that a test can be used to conclude whether the chemical is safe to use and that the test does not need to be repeated.

ECHA’s advice on how to apply dose selection for repeated dose toxicity and reproductive toxicity is aligned with OECD guidelines and guidance documents.

ECHA’s Director for Hazard Assessment, Mike Rasenberg says: “The amended REACH annexes and our instructions guide companies to do toxicity tests using the correct dose level. We need to ensure that any test results can reliably show whether a chemical causes severe health effects or not. In doing so, we avoid companies having to redo inconclusive tests and causing more suffering to animals.”

The ECHA guidance document on Information Requirements and Chemical Safety Assessment – Chapter R.7a will be revised to take the amended REACH annexes into account. It will be published later in 2022.


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