Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

According to the BCF/BAF methods, the regression based method calculates a BCF of 3 and the Arnot-Gobas method predicts a BCF of 0.89. Therefore these values are consistent and predict that the substance is non-bioaccumulable, supporting the expectations from the highlog KOWand rapid biodegradability.

Additional information

ANSWER TO TESTING PROPOSAL DECISION number: TPE-D-2114314157-57-01/F

No direct information is available on the BCF of the substance in fish or other organisms. Furthermore, indirect information on physico-chemical properties is not experimentally available due to the extreme hydrophobicity of this substance. The solubility cannot be experimentally measured and the estimate of thelog KOWis inadequate as based on 1) a simple ratio of octanol and water solubilities rather than a genuine partition value and 2) a less than value for solubility which has been calculated to be overestimated by several orders of magnitude.

Nevertheless, these data can be used in a weight of evidence approach to justify waiving a BCF study. First, a standard BCF study would not be technically possible to perform due to the insolubility of the test substance such that it would not be possible to maintain the test solution concentration. Therefore the only option would be to perform a fish dietary accumulation study which in itself cannot directly provide a BCF value. With a predictedlog KOWof 17, the substance is well beyond the threshold for potential B or vB according to ECHA PBT guidance. Moreover, Squalane has been shown to be readily biodegradable and, as a long chain hydrocarbon, may be expected to be rapidly metabolized by fish. Thus, a modelling approach is considered sufficient as an alternative to an experimental method in this case. According to the BCF/BAF methods, the regression based method calculates a BCF of 3 and the Arnot-Gobas method predicts a BCF of 0.89. Therefore these values are consistent and predict that the substance is non-bioaccumulable, supporting the expectations from the highlog KOWand rapid biodegradability.

For all the above reasons, studies on Bioaccumulation of Squalane are not considered scientifically justifiable.