Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: according to OECD 301B (Sturm test); experimental part equivalent to GLP

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guidelineopen allclose all
according to guideline
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
according to guideline
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
GLP compliance:
experimental part acc. to GLP standards but no quality control, sample storage and GLP certificate

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:

Study design

Oxygen conditions:
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Origin of inoculum: municipal sewage treatment plant Frankfurt-Sindlingen, Germany
Source: washed activated sludge of municipal sewage treatment
Preparation of suspension: activated sludge sediment centrifugated twice and resuspended in de-ionized water
Used quantity of inoculum: 10 ml/L suspended sludge
Pretreatment: acc. to guideline; pre-aeration of supernatant for 5 days to deactivate carbon dissolved in activated sludge
Preconditions: not pre-adapted to the test substance and the reference material
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
23.97 mg/L
Based on:
test mat.
Initial conc.:
23.53 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
Due to the low solubility of the tested substance no stock solution was prepared. The tested substance was added directly to the test flasks.
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradation
% degradation (CO2 evolution)
Sampling time:
28 d
Details on results:
The value %Degr. is the mean value of two test flasks with two different initial concentrations of the test substance (see section: initial test substance concentration);
The %Degr. value is based on the ratio of determined CO2 formation and the theoretical CO2 formation.
Determinded values were corrected by control values from a blank test performed without any testing substance.
The CO2-evolution of the blank test was below 50 mg/L after 28 days.

BOD5 / COD results

Results with reference substance:
The reference test using benzoic acid sodium salt as reference substance provided a CO2-evolution of more than 60% within 14 days (mean value of 2 tests in 2 test flasks). The %Degr. value is based on the ratio of determined CO2 formation and the theoretical CO2 formation.
The CO2-evolution of the blank test was below 50 mg/L after 28 days.

Applicant's summary and conclusion

Validity criteria fulfilled:
Interpretation of results:
under test conditions no biodegradation observed
The test item is not (readily) biodegradable.
Executive summary:

The ready biodegradability of Naphtol AS-VL was tested using a non adapted activated sludge in the CO2 evolution test for a period of 28 days according to OECD guideline 301 B.

No (ready) biodegradation was found (%Degr. = 0)

The validity criteria of the guideline are fulfilled.