Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Short-term toxicity

GLP guideline studies evaluating the short-term toxicity of Ethanone, 1-(2-hydroxy-5 nonylphenyl)-, oxime, branched (CAS 244235-47-0) to three trophic levels (fish, invertebrates, algae) are available. The test results indicate that the test substance is acutely very toxic to aquatic organisms and that fish are more sensitive than algae and invertebrates.

The toxicity of the test substance to microorganisms was evaluated in a study according to OECD guideline 209 under GLP conditions. In a static study domestic activated sludge was exposed for 3h. An increase of respiration was recorded in all treatments compared to the control values. Based on this result it can be concluded that the test substance does not have any effects on microbial community in STPs and is not expected to inhibit the degradation process.

 

Long-term toxicity

Long-term tests evaluating the acute toxicity of Ethanone, 1-(2-hydroxy-5 nonylphenyl)-, oxime, branched (CAS 244235-47-0) to invertebrates and algae are available. 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 4-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 4-nonylphenol it can be concluded that 4-nonylphenol exhibit a higher aquatic toxicity compared to Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (see table below). Therefore, using data from 4-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).

Substance

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

Phenol, 4-nonyl, branched*

CAS number

244235-47-0

84852-15-3

Structure

see attachment

 see attachment

Molecular formula

C17H27NO2

C15H24O

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

 

 

Biodegradability

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)

Hydrolysis

not relevant

Ecotoxicology

 

 

Short-term toxicity to fish

[96h-LC50]

0.46 mg/L (EU method C.1)

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]

9.55 mg/L (OECD 202)

0.08 – 0.14 mg/L (different methods)

Long-term toxicity to aquatic invertebrates

[21d-NOEC]

2.8 mg/L (OECD 211)

0.024 - 0.116 mg/L (different methods)

Short-term toxicity to algae

[72h-EC50]

760 mg/L(OECD 201)

0.33 - 1.3 mg/L (different methods)

Long-term toxicity to algae

[72h-NOEC/EC10]

472 mg/L (OECD 201)

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

Toxicity to microorganisms

[EC50]

> 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

Data used to assess the aquatic toxicity of Ethanone, 1-(2-hydroxy-5nonylphenyl)-, oxime, branched are highlighted in bold.

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

The test results indicate that the test substance is very toxic to aquatic organisms based on long-term exposure and that fish are more sensitive than algae and invertebrates.

 

Endocrine mode of action

No study is available focusing on potential effects of Ethanone, 1-(2-hydroxy-5 nonylphenyl)-, oxime, branched (CAS 244235-47-0) based on an endocrine mode of action. However, various studies are available assuming endocrine disrupting effects of 4-nonylphenol in fish and invertebrates (see ECHA 2012, SVHC Support Document). In general, effects occur in the range of 1 to 10 µg/L. Thus, the PNEC value derived for freshwater and marine water on the basis of a long-term toxicity fish test with 4-nonylphenol is considered to be sufficiently low to also cover effects related to this specific mode of action.