Registration Dossier

Administrative data

Endpoint:
biodegradation in soil: simulation testing
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because direct and indirect exposure of soil is unlikely
other:
Justification for type of information:
In accordance with Column 2 of Annex IX section 9.2.1.3 of REACH, soil simulation testing (for substances with a high potential for adsorption to soil) need not be conducted if:
- the substance is readily biodegradable, or
- direct and indirect exposure of soilt is unlikely.

The substance was tested according to OECD 301C and after 28 days 36% degradation was reported and therefore the substance is not identified as readily biodegradable.
However, hydrolysis of the substance has been identified as the main route of degradation (abiotic). Results of an hydrolysis as function of pH study (OECD) showed the estimated half-life of the substance at 25°C to be less than 2 minutes at pH 4, 7 and 9.
It is therefore considered the soil simulation testing will provide little additional informaiton since rapid degradation by hydrolysis is already assumed.
In addiiton, the hydrolysis study proposed the hydrolysis product to be Hydroxyethyl sulphate [Molecular weight: 142.1; Smiles: OCCOS(=O)(=O)O]. This hydrolysis product is predicted to be readily biodegradable using EPISUITE model BIOWIN v4.10.

Direct and indirect exposure of soil is considered unlikely.
The substances partition coefficient (log Pow -0.45) and adsorption coefficient (log Koc <1.25) indicates the substance has low potential for adsorption to soils and is therefore not likely to partition into the soil compartment from the aquatic environment.
The hydrolysis product, hydroexyethyl sulphate is also expected to have low potential for adsorption to soils, based on predicted log Pow (-3.95) and log Koc (<1, from EPISUITE model KOCWIN v2.00)

The chemical safety assessment does not indicate the need to investigate further the degradation of the substance and its degradation products.

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion