Registration Dossier

Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

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Administrative data

biodegradation in water: simulation testing on ultimate degradation in surface water
Type of information:
experimental study planned
Please see "Justification for type of information" free text field for further details.
Justification for type of information:
The registered substance has a log Kow of 1.6 and a water solubility of 4 g/L. It is hydrolytically rather stable with half-lifes > 1 year at pH 4 and 7, while short with 15 d at pH 9. Photo-transformation in air is short with 0.4 days. Ready biodegradation was observed and determined as 50 % after 28 days in an OECD 301F study, while inherent biodegradation was determined to be 73 % after 28 days in an OECD 302C study.
In the relevant tonnage band there is the requirement to conduct a simulation study for degradation in water, which basically applies in this case based on the log Kow, water solubility and biodegradation data.
The wainving options do not (clearly) apply:
a) highly insoluble in water: Does not apply, as the substance is well soluble in.
b) ready biodegradability: The substance is certainly not persistent but the criterion for ready biodegradability was not fulfilled.
c) Direct and indirect exposure unlikely: There is no data to allow a conclusion on this criterion. As the substance is not classified for environmental hazards there is no need to provide a CSR and, therefore, it may not be demonstrated that the potential for direct or indirect emissions is low, although this is expected based on the uses of the substance (e.g., industrial indoor uses).
Moreover, it should be considered that the substance is not classified for environmental hazards. There were no effects in the environment as no toxicity was observed up to the highest test concentrations in each study. Thus, the PNECs were derived using the EC/LC0 only (or the EPM method).
The available data, thus, underlines that the substance is not toxic or persistent in the environment. Based on the uses it is rather unlikely that direct or indirect emission to environment occur (even if there is no such data).
Thus, the registrant asks ECHA to decide if the simulation study on degradation in water (OECD 309) is required or if the data is sufficient to omit the data requirement.

Data source

Materials and methods

Test guideline
according to guideline
OECD Guideline 309 (Aerobic Mineralisation in Surface Water - Simulation Biodegradation Test)

Test material

Constituent 1
Chemical structure
Reference substance name:
2-benzofuran-1,3-dione, addition product with 2-(2-hydroxyethoxy)ethanol, ethoxylated
EC Number:
Molecular formula:
Not applicable (UVCB substance)
2-benzofuran-1,3-dione, addition product with 2-(2-hydroxyethoxy)ethanol, ethoxylated
Test material form:
Details on test material:
Clear colourless viscous liquid

Results and discussion

Applicant's summary and conclusion