5-(C11-C12 alkyl, branched)-2-hydroxy-benzaldehyde oxime

Bioaccumulation: aquatic / sediment

Description of key information

5-[C11-12 (branched) alkyl]-2-hydroxybenzaldehyde oxime does not bioaccumulate in aquatic or sediment organisms.

Key value for chemical safety assessment

BCF (aquatic species):

159 dimensionless

Additional information

Since no studies assessing the bioaccumulation potential of 5-(C11-C12 alkyl, branched)-2-hydroxy-benzaldehyde is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to the structurally related source substance Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched (CAS 174333-80-3) was conducted. The read across justification document is attached to chapter 13.

The bioaccumulation study with the source substance was performed according to GLP and OECD guideline 305 using Oncorhynchus mykiss as test organism. The fish were exposed for 4 weeks followed by a three week depuration period. Test substance concentrations of 7 and 35 µg/L were used. Based on whole body weight and total fat and assuming steady state, for both concentrations a plateau was reached after 6 days. The BCF is determined to be 138 and 159, respectively. While one fish died, neither abnormal behaviour nor abnormal growth was observed. Depuration was achieved after 4 and 8 days, respectively. Given the low measured BCF value (which is much lower than the threshold value of 2000 listed in ECHAs Guidance on information requirement and chemical safety assessment Chapter R.11) and the depuration, it can be concluded that the test substance does not accumulate remarkably in fish. Based on the high structural similarity which leads to similar behavior in the environment (as explained in the analogue justification document) this conclusion can also be considered true for 5-(C11-C12 alkyl, branched)-2-hydroxy-benzaldehyde.

This conclusion is supported by a valid QSAR calculation provided in the dossier as well as a bioaccumulation study listed in the REACh dossier of Phenol, dodecyl-, branched (CAS 121158-58-5). The QSAR calculation (using the regression method as well as the Arnot-Gobas method) resulted in BCF values between 126.6 and 1210, which is below the ECHA criterion (of 2000) indicating a substance to be bioaccumulative. The OECD guideline study (OECD 305) resulted in BCF values between 289 and 1601 and thus confirmed the results of the QSAR calculation. Unfortunately, a robust study summary cannot be provided due to ownership reasons.