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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Ethanone, 1-(2-hydroxy-5 nonylphenyl)-, oxime, branched is very toxic to aquatic organisms at acute and long-term sublethal exposure.

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 the structurally very similar source substance Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched (CAS 174333-80-3), was conducted. The only structural difference between the source substance and the main component of the target substance is the lack of a methyl group at the oxime carbon of the source substance. The read across is justified due to (i) the similarity of structure and functional groups and accordingly (ii) similar physico-chemical properties resulting in a similar environmental fate and ecotoxicity profile (see table below and Ananlogue justification document in chapter 13).

The available long-term toxicity data indicate that the substance is vry toxic to aquatic organisms at sublethal chronic exposure.


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 Benzaldehyde, 2-hydroxy-5-nonyl, oxime, branched (CAS 174333-80-3) is considered to be sufficiently low to also cover effects related to this specific mode of action.