Benzaldehyde, 5-dodecyl-2-hydroxy-, oxime, branched

Bioaccumulation: aquatic / sediment

Description of key information

Benzaldehyde, 2-hydroxy-5-dodecyll, oxime, branched 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 Benzaldehyde, 2-hydroxy-5-dodecyl-, oxime, branched (CAS1233873-37-4) 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 only structural difference between the source substance and the target substance is the slightly (two C-atoms) shorter carbon chain of the source substance at the the phenol ring. The read across is justified due to (i) the similarity of structure and functional groups and accordingly (ii) similar physico-chemical properties resulting in a similar environmental fate and ecotoxicity profile:

Table 1: Physico-chemical properties, efate and ecotoxicological profile of the target and the source substance

Substance	Benzaldehyde, 2-hydroxy-5 -dodecyl, oxime, branched	Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched
CAS number	1233873-37-4	174333-80-3
Structure	see attachment	see attachment
Molecular formula	C19H31N1O2	C16O2N1H25
Molecular weight	~ 305.46 g/mole	~ 263 g/mole
PC parameter
Water solubility	0.3 mg/L (OECD 105)	0.4 mg/L (EU method A.6)
Partition coefficient	> 5.7 (EU method L3B3 A/63 -73)	5.5 (EU method A.8)
Vapour pressure	< 0.39 Pa at 20 °C (estimation based on Grain-Watson method)	0.37 Pa at 20 °C (OECD 104)
Environmental fate
Biodegradability	-	0 % in 28 days (OECD 302c)
Adsorption [log KOC]	4.4 (OECD 121)	3.7 (OECD 121)
Hydrolysis	not relevant due to low water solubility
Ecotoxicology
Short-term toxicity to fish [96h-LC50]	-	1.1 mg/L (EU method C.1)
Short-term toxicity to aquatic invertebrates [48h-EC50]	-	2.7 mg/L (EU method C.2)
Long-term toxicity to aquatic invertebrates [21d-NOEC]	-	0.189 mg/L (OECD 211)
Short-term toxicity to algae [72h-EC50]	498.32 mg/L (OECD 201)	36.3 mg/L (OECD 201)
Long-term toxicity to algae [72h-NOEC]	101.2 mg/L (OECD 201)	14.9 mg/L (OECD 201)
Toxicity to microorganisms [3h-EC10]	-	200.4 mg/L (OECD 209)

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 above) this conclusion can also be considered true for Benzaldehyde, 2-hydroxy-5-dodecyl-, oxime, branched (CAS1233873-37-4). This conclusion is supported by a bioaccumulation study listed in the REACh dossier of Phenol, dodecyl-, branched (CAS 121158 -58 -5). The OECD guideline study (OECD 305) resulted in BCF values between 289 and 1601, which is below the ECHA criterion (of 2000) indicating a substance to be bioaccumulative.