Ecotoxicity
Excerpt from ARTF Category Justification - Following the Read-Across Assessment Framework (RAAF), the read-across approach for ecotoxicity endpoints is described in scenario 6 (different compounds have quantitatively similar properties) and governed by AE 6.3 (common underlying mechanism, quantitative aspects).
As discussed in the review of structural and physico-chemical properties, acrylic acid has a different profile compared to the six acrylate esters included in the read-across approach for aquatic toxicity. Existing data on aquatic toxicity illustrates difference in hazard profile between acrylic acid and the acrylate esters. The available data indicates toxicity at the same order of magnitude across all three trophic levels for all acrylate esters within the category. Acrylic acid is the only outlier to this trend, as it displays a somewhat different level of toxicity. It can be concluded that read-across among acrylate esters is applied with a high level of certainty. An overview of the ecotoxicity information on acrylate esters is provided below. For comparison the acrylic acid ecotoxicity data is also included.
Short-Term Toxicity to fish - The results of all short-term toxicity to fish studies conducted on the esters yield extremely similar results across all substances within the category across both freshwater and marine species, supporting the broader use of the category approach. Read-across to data on the toxicity of the substances to marine species is not technically required but the use of data on MA, EA and nBA, to address the endpoints for other substances, is considered valid.
Long-Term Toxicity to Fish - Acute effect levels were determined to be in the same range of concentrations for all three trophic levels and it is considered that a similar trend would be observed for long-term effects, as supported by available long-term data for invertebrates and algae.As such, available information on long-term toxicity to algae and aquatic invertebrates was used to assess long-term toxicity towards aquatic organisms. Further testing on fish (vertebrate) is, therefore, not necessary or justified and similarly the need to demonstrate the suitability of read-across within the category for this endpoint is not considered necessary at this time.
Short-Term Toxicity to Aquatic Invertebrates - The results of all studies conducted on the esters yield extremely similar results across all substances within the category for both freshwater and marine species, supporting the broader use of the category approach. Read-across to data on the toxicity of the substances to marine species is not technically required but the use of data on MA to address the endpoints for other substances is considered valid.
Long-term Toxicity to Invertebrates - Given that the results of all studies across all three trophic levels are broadly the same, and that there is no marked difference among any of the acrylate esters within the category, it is concluded that this trend would extend to long-term toxicity on aquatic invertebrates. The available long-term daphnia studies conducted on the acrylate esters yield very similar results, supporting the use of the category approach. Thus, it is considered justified to use read-across to the data on EA, nBA and 2EHA to address this endpoint for the other category substances. Read-across is applied with a high level of confidence.
For more information, see Category Justifcation Document for use under EU REACH.