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:
1999-09-23 to 1999-10-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study, no GLP.
Qualifier:
according to
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Version / remarks:
December 1992
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Version / remarks:
adopted 17 July 1992
Deviations:
no
GLP compliance:
no
Remarks:
SN EN 45001 compliance
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from the aeration tank of a municpial biological waste water treatment plant (ARA Werdhölzli, CH-8048 Zürich, 1999-09-22, 4:30 pm), not adapted, not pre-conditioned
- Pretreatment: Sludge was washed twice with tap water prior to the test
- activated sludge was used immediately after sampling
- Initial cell/biomass concentration: 30 mg/L dry matter in the final mixture
Duration of test (contact time):
28 d
Initial conc.:
158 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
TEST CONDITIONS
- Composition of medium: test medium prepared with deionised water (conductivity: <1.5 µS/cm; DOC <0.3 mg/L) according to OECD Guideline 301 F
- Additional substrate: none
- Test temperature: 22 ± 0.5 °C
- pH: at start: 7.4; at the end 7.3 (inoculum blank), 6.8 (procedure control), 6.6 (test suspensions)
- pH adjusted: to 7.4 if necessary
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 1200 mL closed glass bottle containing a total volume of test solution of 400 mL agitated on an orbital shaker at 100 rpm
- Number of culture flasks/concentration: one test concentration of 158 mg/L in two replicates
- Test performed in open system: no

SAMPLING
- Sampling frequency: Days 0, 1, 4, 8, 12, 14, 18, 21, 25, 28

CONTROL AND BLANK SYSTEM
- Inoculum blank: containing inoculum and test medium (two replicates)
- Abiotic sterile control: not conducted
- Toxicity control: not conducted
- Other: Procedure control: containing inoculum, test medium and sodium benzoate as ready biodegradable reference compound
Reference substance:
benzoic acid, sodium salt
Remarks:
100 mg/L
Preliminary study:
not available
Test performance:
not available
Parameter:
% degradation (O2 consumption)
Value:
75
Sampling time:
28 d
Parameter:
% degradation (O2 consumption)
Value:
56
Sampling time:
14 d
Remarks on result:
other: end of the 10 day window
Details on results:
- The 10 day window started at day 4. At the end of the 10 day window, 54 % biodegradation were attained. After 28 days, 75 % biodegradation were attained. The positive control reached 83% degradation after 14 days.
- The biodegradation as calculated according to the DOC measurement attained 97 % for the test substance and 99 % for the procedure control.
Results with reference substance:
The referene substance sodium benzoate degraded normally under the test conditions (83 % after 14 days).
Validity criteria fulfilled:
yes
Interpretation of results:
inherently biodegradable
Conclusions:
THFMA did not pass the level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window and, cannot be termed as readily biodegradable. However, after 28 days the degradation of THFMA reached 75%. According to the Guidance on information requirements and chemical safety assessment, Chapter R.7b, version 1.1, May 2008, the test substance may be termed as inherently biodegradable.
Executive summary:

The ready biodegradation of THFMA was investigated in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) adopted 17 July 1992 and EU Method C.4 -D, 29 December 1992, over a period of 28 days using activated sludge sampled from the aeration tank of a municipal sewage treatment plant as inoculum. The biodegradation rate was determined by measurement of O2 consumption. Inoculum blank and procedure control with the reference substance sodium benzoate were performed.

The 10 day window started at day 4. 54% biodegradation were reached at the end of the 10 day window and thus failing the criterion for ready biodegradability. However, the pass level of 60% biodegradation was reached after ca. 18 days; after 28 days the degradation of THFMA reached 75%. According to the Guidance on information requirements and chemical safety assessment, Chapter R.7b, version 1.1, May 2008, the test substance can be termed as inherently biodegradable.

The functional control reached the pass level >60% after 14 d (83%).

This study is regarded as reliable without restriction and satisfies the guideline requirements for ready biodegradation.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

readily biodegradable, but failing 10 d window; OECD Guideline 301 F (Manometric Respirometry Test); no GLP + EPIWEB prediction

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable but failing 10-day window

Additional information

One study on biodegradation of THFMA is available, which is considered as reliable without restrictions (RL=1):

The ready biodegradation of THFMA was investigated in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) adopted 17 July 1992 and EU Method C.4 -D, 29 December 1992, over a period of 28 days using activated sludge sampled from the aeration tank of a municipal sewage treatment plant as inoculum. The biodegradation rate was determined by measurement of O2 consumption. Inoculum blank and procedure control with the reference substance sodium benzoate were performed.

The 10 day window started at day 4. 54% biodegradation were reached at the end of the 10 day window and thus failing the criterion for ready biodegradability. However, the pass level of 60% biodegradation was reached after ca. 18 days; after 28 days the degradation of THFMA reached 75%.

The functional control reached the pass level >60% after 14 d (83%).

This is supported by data obtained from an estimation by calculation: Based on the prediction of EPIWEB version 4.1, BIOWIN (v4.10) THFMA is considered to be readily biodegradable.

In the available test the 10 days window was only narrowly failed (54% at the end of the 10 days window). Thus, based on the available data and on teh EPIWEB estimate, THFMA is considered to be readily biodegradable.