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Ecotoxicological information

Long-term toxicity to fish

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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

EC10, LC10 or NOEC for freshwater fish:
0.006 mg/L

Additional information

Since no study assessing the long-term toxicity of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0) to fish is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to nonylphenol was conducted , which is a secondary component and structurally similar to the main component of the substance. The only structural difference between the source substance and the target substance is the lack of a ketoxime group at the phenol ring of the molecule.

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 nonylphenol it can be concluded that nonylphenol exhibit a higher aquatic toxicity compared to Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (see table below). Therefore, using data from nonylphenol to assess the intrinsic hazard of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched is considered to be a very conservative approach (worst case scenario).


Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched

Phenol, 4-nonyl, branched*

CAS number




see attachment

 see attachment

Molecular formula



Molecular weight

~ 277 g/mole

~ 220.35 g/mole

PC parameter



Water solubility

> 0.02 < 1 mg/L (EU method A.6)

5.7 mg/L (ASTM E 1148-02)

Partition coefficient

> 5.7(EU method A.8)

5.4 (OECD 117)

Vapour pressure

< 1.5 Pa at 20 °C (OECD 104)

~1 Pa at 20 °C (ASTM-D 2879)

Environmental fate




1 % in 28 days (BODIS)

non-adapted inoculum:

0 % in 28 days (OECD 301B)


adapted inoculum:

48.2-62 % in 28 days (OECD 301B)

Adsorption [log KOC]

3.9 (OECD 121)

4.35 - 5.69 (EPA OTS 796.2750)


not relevant




Short-term toxicity to fish


0.46 mg/L (EU method C.1)

0.05 – 0.22 mg/L (different methods)

Long-term toxicity to aquatic invertebrates



0.006 mg/L (ASTM E 1241-05)

Short-term toxicity to aquatic invertebrates


9.55 mg/L (OECD 202)

0.08 – 0.14 mg/L (different methods)

Long-term toxicity to aquatic invertebrates


2.8 mg/L (OECD 211)

0.024 - 0.116 mg/L (different methods)

Short-term toxicity to algae


760 mg/L(OECD 201)

0.33 - 1.3 mg/L (different methods)

Long-term toxicity to algae


472 mg/L (OECD 201)

0.5 mg/L (Algal growth inhibition test according to UBA 1984)

Toxicity to microorganisms


> 1000 mg/L (OECD 209)

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 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 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 Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0).