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Environmental fate & pathways

Biodegradation in soil

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Description of key information

DisT50 = 2.1 - 10.3 days for different branched 4-nonylphenol isomers (read across). 

Key value for chemical safety assessment

Additional information

Since no simulation studies assessing the biodegradability of Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0) in soil are 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 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 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

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

Phenol, 4-nonyl, branched*

CAS number

244235-47-0

84852-15-3

Structure

see attachment (chapter 6.1)

 see attachment (chapter 6.1)

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

 

Several soil - simulation studies with 4-nonylphenol are available in the literature. However, only one focussed on different branched nonylphenol isomers. Shan et al. (2011) studied the degradation of five p-nonylphenol (4-NP) isomers including four branched (4-NP38, 4-NP65, 4-NP111, and 4-NP112) and one linear (4-NP1) isomers in a rice paddy soil using 14C- and 13C-ring-labelled nonylphenol. Degradation followed an availability-adjusted first-order kinetics with the decreasing order of half-life 4-NP111 (10.3 days) > 4-NP112 (8.4 days) > 4-NP65 (5.8 days) > 4-NP38 (2.1 days) > 4-NP1 (1.4 days). One metabolite of 4-NP111 with less polarity than the parent compound occurred rapidly and remained stable in the soil. At the end of incubation (58 days), bound residues of 4-NP111 amounted to 54% of the initially applied radioactivity and resided almost exclusively in the humin fraction of soil organic matter, in which chemically humin-bound residues increased over incubation.

In conclusion, branched nonylphenol is mineralized slowly but integrated into organic matter rapidly in soil. Based on the reasons given above this conclusion is also considered to be true for Ethanone, 1-(2-hydroxy-5-nonylphenyl)-, oxime, branched (CAS 244235-47-0)