Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Ready biodegradfation extended to 60 day period - performed 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Guideline study, but extended to assess potential for inherent biodegradation.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)
Version / remarks:
Extended to 60 days
GLP compliance:
yes
Specific details on test material used for the study:
Batch BP16120710, supplied as 50% in water.
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Non-adapted from municiple treatment works
Duration of test (contact time):
60 d
Initial conc.:
ca. 2 mg/L
Based on:
act. ingr.
Parameter followed for biodegradation estimation:
DOC removal
Reference substance:
acetic acid, sodium salt
Parameter:
% degradation (DOC removal)
Value:
ca. 3
Sampling time:
13 d
Parameter:
% degradation (DOC removal)
Value:
ca. 6
Sampling time:
20 d
Parameter:
% degradation (DOC removal)
Value:
ca. 18
Sampling time:
28 d
Parameter:
% degradation (DOC removal)
Value:
ca. 22
Sampling time:
60 d
Details on results:
Significant lag period with little biodegradation.
Slow rate of biodegradation over 60 days, but likely ultimately biodegradable.
Validity criteria fulfilled:
yes
Interpretation of results:
inherently biodegradable, not fulfilling specific criteria
Conclusions:
Significant lag period with little biodegradation; this was anticipated from modelling and the 60 day study was planned with this in mind.
However, total biodegradation was expected to be significantly higher from modelling.

Description of key information

Significant lag period with little biodegradation; this was anticipated from modelling and the 60 day study was planned with this in mind.

However, total biodegradation was expected to be significantly higher from modelling.

The results for the seawater study showed initial biodegradation that slowed by Day 20 with no further biodegradation.

Seawater studies without added innoculum are hard to pass and it is predicted that higher levels of biodegradation woudl be seen using sewage innoculum in a freshwater study.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable, not fulfilling specific criteria

Additional information

[Type of water: marine water]