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

Long-term toxicity to fish

Description of key information

NOEC (91d) = 0.006 mg/L (measured) for Oncorhynchus mykiss (ASTM E 1241-05, read across)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.006 mg/L

Additional information

Since no study assessing the long-term toxicity of Benzaldehyde, 2-hydroxy-5 -dodecyl, oxime, branched (CAS 1233873-37-4) to fish is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to Phenol, 4-nonyl-,branched (CAS 84852-15-3) was conducted, which is structurally similar to the main component of the substance. The structural difference between the source substance and the target substance is the lack of a aldoxime group at the phenol ring of the molecule and a C9 branched carbon chain instead of a C12 branched carbon chain. The read across is justified by similarity of structure and functional groups and accordingly similar physico-chemical properties, which is expected to result in similar environmental behavior and fate (see table).

Substance	Benzaldehyde, 2-hydroxy-5 -dodecyl, oxime, branched	Phenol, 4-nonyl, branched^*
CAS number	1233873-37-4	84852-15-3
Structure	see attachment (chapter 6.1)	see attachment (chapter 6.1)
Molecular formula	C19H31N1O2	C15H24O
Molecular weight	~305.46 g/mole	~ 220.35 g/mole
PC parameter
Water solubility	0.3 mg/L (OECD 105)	5.7 mg/L (ASTM E 1148-02)
Partition coefficient	> 5.7 (EU method L3B3 A/63 -73)	5.4 (OECD 117)
Vapour pressure	< 0.39 Pa at 20 °C (estimation based on grain-Watson method)	~1 Pa at 20 °C (ASTM-D 2879)
Environmental fate
Biodegradability	-	non-adapted inoculum: 0 % in 28 days (OECD 301B)   adapted inoculum: 48.2-62 % in 28 days (OECD 301B)
Adsorption [log KOC]	4.4 (OECD 121)	4.35 - 5.69 (EPA OTS 796.2750)
Hydrolysis	not relevant
Ecotoxicology
Short-term toxicity to fish [96h-LC50]	-	0.05 – 0.22 mg/L (different methods)
Long-term toxicity to aquatic invertebrates [NOEC]	-	0.006 mg/L (ASTM E 1241-05)
Short-term toxicity to aquatic invertebrates [48h-EC50]	-	0.08 – 0.14 mg/L (different methods)
Long-term toxicity to aquatic invertebrates [21d-NOEC]	-	0.024 - 0.116 mg/L (different methods)
Short-term toxicity to algae [72h-EC50]	498.32 mg/L (OECD 201)	0.33 - 1.3 mg/L (different methods)
Long-term toxicity to algae [72h-NOEC/EC10]	101.2 mg/L (OECD 201)	0.5 mg/L (Algal growth inhibition test according to UBA 1984)
Toxicity to microorganisms [EC50]	-	950 mg/L (OECD 209)

* Data were taken from Phenol, 4-nonyl-,branched (CAS 84852-15-3) dossier published on the ECHA data base

The available study investigated the long-term toxicity of 4-nonylphenol to early life stage of rainbow trout (Oncorhynchus mykiss) under flow through conditions (Spehar et al. 2010). The study was performed according to ASTM guideline E 1241-05 over an exposure time of 91 days. 100 fertilized eggs per test concentration were exposed to measured concentrations of 6.0, 10.3, 23.1, 53.0 and 114 µg/L 4-nonylphenol. The test system was maintained at ~ 11 ºC and a pH of 6.97. Mean percent hatch of any test concentration was not significantly different from controls. Time to hatch was 39 ± 5 days with swim-up at approximately at day 45. The most sensitive end point was growth. The 91-day NOEC value, based on sublethal effects (growth measured by mean standard length, wet weight and dry weight) is determined to be 6.0 µg/L.

Based on the reasons given above this value is considered to be sufficiently conservative to be used for PNEC derivation of Benzaldehyde, 2-hydroxy-5 -dodecyl, oxime, branched (CAS 1233873-37-4).