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

Short-term toxicity to aquatic invertebrates

Description of key information

EL50 (48h) = 2.7 mg/L (nominal, WAF, active ingredient) for Daphnia magna (EU method C.2, read across)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.7 mg/L

Additional information

Since no studies assessing the short-term toxicity of Benzaldehyde, 2-hydroxy-5-dodecyl-, oxime, branched (CAS1233873-37-4) to aquatic invertebrates 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 (chapter 6.1)	see attachment (chapter 6.1)
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 study with the read across substance was performed according to EU Method C.2 under GLP conditions using Daphnia magna as test organism (Kirch 1998). Test concentrations of 1 to 100 mg/L were applied as loading rate WAFs. Analytical monitoring was not performed. All validity criteria were fulfilled. The EL50 is determined to be 2.7 mg a.i./L. 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).