Propane-1,2,3-triyl 3,5,5-trimethylhexanoate

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Data waiving:

other justification

Justification for data waiving:

other:

Additional information

Data on the toxicity of propane-1,2,3-triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1) to terrestrial arthropods are not available. Toxicity of the substance to terrestrial organisms is considered as unlikely. In a study on the ready biodegradability the substance reached a degradation rate of 60% but failed the 10-day window criterion. Thus, a rapid and extensive removal of the substance in sewage treatment plants can be expected. Furthermore the Guidance on information requirements and chemical safety assessment, Chapter R7.b (ECHA, 2012) states that once insoluble chemicals enter a standard STP, they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms. Due to the high log Koc a significant degree of removal of these substances from the water column due to adsorption can be expected (Guidance on information requirements and chemical safety assessment, Chapter R.7a (ECHA, 2012)). Consequently a significant release to the environment of the substance via STP effluents is not expected and thus an exposure of terrestrial organisms is unlikely. However, when terrestrial organisms are exposed to the substance toxic effects are not expected as demonstrated by the available studies on the acute and chronic toxicity to aquatic organisms. The absence of chronic or long-term toxicological effects in aquatic organisms up to the substance solubility limit, can, as ECHAs Guidance R.7c states, can be used as part of a Weight of Evidence argument to modify/waive the data requirements of Annex IX and X. There is a chronic test on aquatic invertebrates available. No effects on Daphnia were observed up to the limit of water solubility. Therefore, it is assumed that due to the lack of chronic aquatic toxicity, long term tests on terrestrial organisms will not result in a different outcome. Therefore no chronic tests for terrestrial organisms are either provided, or deemed as necessary for the chemical safety assessment. Bioaccumulation or biomagnification through the food chain of the substance is not probable. Though the high log Pow value (log Pow > 10) indicates a potential of the substance to bioaccumulate a relevant uptake is not expected due to the high molecular size. This also supported by low BCF/BAF values (0.94 L/kg; Arnot-Gobas) calculated for the substance indicating a low bioaccumulation potential. Overall, the substance is unlikely to pose a risk for terrestrial organisms based on a) the lack of exposure and b) the lack of adverse effects in aquatic ecotoxicity tests.