Testing Proposal Evaluation
Where information requirements addressing a number of intrinsic properties of a substance (as specified by the REACH Annexes) cannot be fulfilled, registrants are responsible for generating this data and providing it in their registration dossier. In some cases the filling of data gaps means that new animal testing will be necessary. REACH however obliges registrants to limit new studies and to conduct animal studies only as a last resort. Registrants must first collect and assess all existing data, precisely identify data gaps and consider whether these can be filled by using either in vitro/ex vivo studies or other alternative approaches, including prediction, methods before any new animal tests are conducted. A testing proposal should be submitted to ECHA and receive their prior approval before testing can start. ECHA’s role in evaluating testing proposals is to ensure that reliable and adequate data will be produced and to prevent unnecessary animal testing.
ECHA will publish every testing proposal that involves vertebrate animals and invite third parties to submit scientifically valid information or studies addressing the substance and hazard endpoints in question that could be taken into account by ECHA in preparing its decision on the testing proposal. The information has to be submitted within 45 days.
Consultations on testing proposals can be found here : http://echa.europa.eu/web/guest/information-on-chemicals/testing-proposals
ECHA’s website has a section with recommendations on how to avoid unnecessary testing on animals:https://echa.europa.eu/support/registration/how-to-avoid-unnecessary-testing-on-animals
It discusses:
- Weight of Evidence (WoE): combination of information from several independent sources to give sufficient evidence to fulfil an information requirement. https://echa.europa.eu/support/registration/how-to-avoid-unnecessary-testing-on-animals/weight-of-evidence
- QSAR models: mathematical models used to predict the physico-chemical, biological & environmental fate properties of compounds from the knowledge of their chemical structure. https://echa.europa.eu/support/registration/how-to-avoid-unnecessary-testing-on-animals/qsar-models.
Note: Unfortunately, most QSAR have not been developed for inorganic chemicals such as metal ions. QICAR models can be developed as an alternative, where intrinsic properties of metals and inorganics are related to their own toxicity (e.g. Le Faucheur et al, 2021 doi:10.1002 / etc. 4960 )
- In vitro methods: in vitro data can be used to fully or partly fulfil information requirements that would otherwise need data to be generated with tests on living organisms (in vivo tests). https://echa.europa.eu/support/registration/how-to-avoid-unnecessary-testing-on-animals/in-vitro-methods
- Grouping and read-across: Grouping of substances and read-across has been extensively used in the REACH registrations of metal-metal compounds. Key for the acceptance of the read-across is the justification, which will be assessed by ECHA. https://echa.europa.eu/support/registration/how-to-avoid-unnecessary-testing-on-animals/grouping-of-substances-and-read-across
Reference documents include:
- The ECHA Read-Across Assessment Framework (RAAF) that structures the evaluation of grouping and read-across under REACH. It includes a main text and scenarios in appendices. https://echa.europa.eu/documents/10162/17221/raaf_en.pdf/614e5d61-891d-4154-8a47-87efebd1851a
- The OECD Guidance on the grouping of chemicals: https://www.oecd.org/en/publications/guidance-on-grouping-of-chemicals-second-edition_9789264274679-en.html
- Read-across and grouping for metals was extensively discussed in the MISA (Metals & Inorganics Sectoral Approach): https://www.reach-metals.eu/metals-and-inorganics-sectoral-approach-misa
Last page update: 7 August 2025