2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one

Biodegradation in water: screening tests

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:

2003-01-06 to 2003-02-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

adopted 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Version / remarks:

adopted 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: ARA Ergolz II, Füllinsdorf, Switzerland
- Laboratory culture: no
- Preparation of inoculum for exposure: The sludge was washed twice with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated.
Based on this ratio, calculated amounts of wet sludge were suspended in test water to obtain a concentration equivalent to 4 g (± 10%) dry material per liter. During holding, the sludge was aerated at room temperature until use. Prior to use, the sludge was diluted with test water to a concentration of 1 g per liter (dry weight basis).
- Concentration of sludge: Defined volumes of this diluted activated sludge were added to test water to obtain a final concentration of 30 mg dry material per liter.
- Water filtered: no

Duration of test (contact time):

28 d

Initial conc.:

20.05 mg/L

Based on:

test mat.

Initial conc.:

14.85 mg/L

Based on:

ThOD/L

Details on study design:

TEST CONDITIONS
- Composition of medium: The test water was prepared according to the testing guidelines.
- Additional substrate: no
- Solubilising agent (type and concentration if used): test water
- Test temperature: 22 - 24°C.
- pH: 7.8 to 7.4
- pH adjusted: yes (with a diluted hydrochloric acid solution)
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 5-liter flasks (amber glass)
- Number of culture flasks/concentration: between 2400 and 3000 mL of untreated test medium

SAMPLING
- Sampling frequency: Samples were taken on Day 2, 5, 7, 9, 12, 14, 19, 23, 27, 28 and 29.
- Sample storage before analysis: After sampling on Day 28, the pH was measured in each test flask. Next, 1 mL of concentrated HCI was added to each test flask and the flasks were aerated overnight to drive off any residual CO2 present. On Day 29, a sample of each absorber flasks was withdrawn and analyzed for IC to determine residual CO2 which was present in the test suspensions on Day 28. In this way, any residual CO2 remaining in the test suspensions was determined as the difference between the amount of IC found before and after acidification.


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

-2.3

Sampling time:

28 d

Details on results:

The CO2 production of the test item in the test media was slightly below the CO2 production of the inoculum controls.

Results with reference substance:

At the end of the test (Day 28), the reference item was degraded by an average of 94%.

The percent biodegradation of the test item was calculated based on a total carbon content (TOC) of 0.74 mg C/mg test item. The CO2 production of the test item in the test media was slightly below the CO2 production of the inoculum controls. Consequently, the test item was found to be not biodegradable under the test conditions within 28 days.

No significant degradation of the test item occurred in the abiotic control under the test conditions.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance is not readily biodegradable (by OECD criteria).

Executive summary:

In this guideline (OECD 301B) study conducted with GLP certification, the test material (EC 444-860-9) was determined to be not readily biodegradable.

Description of key information

Study conducted to recognised testing guidelines with GLP certification.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The test substance is not readily biodegradable (by OECD criteria). It is poorly biodegradable.

The biodegradability of the test substance was investigated in a GLP test performed according to OECD guideline 301B. Using non-adapted domestic sludge no biodegradation was observed after 28 days (RCC Ltd. 2003).

A supporting study according OECD 301C is available (Institute of Ecotoxicology Co., Ltd. 2004). After 28 d no biodegradation was observed. Therefore, the test substance was not readily biodegradable under the conditions of these tests.