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

Toxicity to terrestrial plants

Description of key information

EC50 (15d) > 1000 mg/kg (nominal, fresh weight) for Brassica rapa (OECD 208, read across)

Additional information

Since no study assessing the toxicity of Benzaldehyde, 2-hydroxy-5-dodecyl, oxime, branched (CAS 1233873-37-4) to terrestrial plants 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 due to the following reasons:

1) The similarity of structure and functional groups and accordingly similar physico-chemical properties result in similar environmental behavior and fate.

2) Based on a profound ecotoxicological data set available for Phenol, 4-nonyl-,branched it can be concluded that Phenol, 4-nonyl-,branched exhibit a higher aquatic toxicity compared to Benzaldehyde, 2-hydroxy-5-dodecyl, oxime, branched (see table below). Therefore, using data from Phenol, 4-nonyl-,branched to assess the intrinsic hazard of Benzaldehyde, 2-hydroxy-5-dodecyl, oxime, branched is considered to be a very conservative approach (worst case scenario).

Substance	Benzaldehyde, 2-hydroxy-5 -dodecyl, oxime, branched	Phenol, 4-nonyl, branched^*
CAS number	1233873-37-4	84852-15-3
Structure	see attachment (chapter 6.3)	see attachment (chapter 6.3)
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 toxicity of 4-nonylphenol to terrestrial plants was investigated according to OECD guideline 208 using L. perenne and B. rapa as test organisms (Domene et al. 2009). Artificial soil according to OECD was used. Germination and biomass production was recorded after an exposure time of 15 days. Fresh weight was found to be a more sensitive endpoint than germination. However, all 15d-EC50 value showed to be > 1g/kg, which is not considered as toxic according to OECD criteria.

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