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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Currently viewing:

Administrative data

Link to relevant study record(s)

biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
supporting study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
according to guideline
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes (incl. QA statement)
Oxygen conditions:
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Activated sludge from laboratory wastewater plant treating municipal sewage.
Concentration of activated sludge in the test assay: 30 mg/L dry substance
Duration of test (contact time):
28 d
Initial conc.:
37 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance:
Key result
% degradation (CO2 evolution)
70 - 80
Sampling time:
28 d
Details on results:
- Duration of adaptation phase: 8 days
- Duration of degradation phase: 20 days
- Degradation degree of DOC at the end of the test, mean value: 90-100 %
Results with reference substance:
- Degradation degree of the reference substance after 14 days: 80-90 %
- Degradation degree in the inhibition control after 14 days: 70-80 %
Validity criteria fulfilled:
Interpretation of results:
readily biodegradable, but failing 10-day window

Description of key information

Readily biodegradable: 79-82% in 28 days (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable
Type of water:

Additional information

Two studies investigating the ready biodegradability of Triisobutyl phosphate (TiBP) are available. The key study was conducted according to GLP and OECD guideline 301B using non-adapted activated sludge from a domestic STP as inoculum (BASF 2019). After 28 days 79-82% degradation of TiBP was observed and the 10d-window was passed. Thus, the substance was classified as readily biodegradable. This was confirmed by a second study also conducted to GLP and OECD guideline 301B, which just missed to fulfill the 10d-window criterion.