2-Propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 17 July 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

29 December 1992

Deviations:

no

Principles of method if other than guideline:

20

GLP compliance:

no

Remarks:

ISO 17025

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 municipal waste water treatment plant, not adapted, not pre-conditioned; ARA Werdhölzli. CH-8048 Zürich (21 February 2007; 10.30 a.m.)
- Concentration of sludge: 30 mg/L suspended solids

The activated sludge was used without adaptation. Prior to the test the sludge was washed twice with tap water.

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Medium: Aerobic mineral salts medium prepared with deionised water (conductivity : <1.5 µS/cm; DOC: <0.3 mg/L)
- Additional substrate: no
- Test temperature: 22 ±0.5°C
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottle containing a total volume of test solution of 2000 ml; aerated with CO2-free air and fitted to gas-absorption bottles containing 125 ml of 0.13 M KOH
- Number of culture flasks/concentration: 2

CONTROL AND BLANK SYSTEM
- Inoculum blank: containing inoculum and test medium (two replicates)
- Abiotic sterile control: no
- Toxicity control: no
- Procedure control: containing inoculum, test medium and sodium benzoate es ready biodegradable reference compound (one replicate)

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

47

Sampling time:

10 d

Parameter:

% degradation (CO2 evolution)

Value:

79.4

Sampling time:

28 d

Results with reference substance:

The positive control, sodium benzoate. reached 96% biodegradation after 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

ISOTRIDECYL METHACRYLATE did not reach the pass level of 60 % for ready biodegradability in the CO2 Evolution Test within the 10 -d window and. therefore, cannot be termed as readily biodegradable. However, the pass level of 60 % was reached after 28 days of incubation .

Executive summary:

The biodegradability ot Isotridecyl methacrylate exposed to microorganisms derived from the activated sludge of a municipal sewage treatment plant was investigated under aerobic staitc exposure conditions.

The biodegradabitity based on CO2 evolution of Isotridecyl methacrylate was calculaled to be 79 % of the theoretical value (ThCO2) atter an incubation time of 28 days. The biodegradation of Isotridecyl methacrylate reached 47 % at the end of the 10-d window. Significant biodegradation of the test substance was observed after a lag phase of about 4 days.

The positive control, sodium benzoate, reached 96 % biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

The calculated biodegradation based on DOC measurement reached 93 % for Isotridecyl methacrylate and 98 % for sodium benzoate.

Isotridecyl methacrylate did not reach the pass level of 60 % for ready biodegradability in the CO2 Evolution Test within the 10 -d window and. therefore, cannot be termed as readily biodegradable. However, the pass level of 60 % was reached after 28 days of incubation.

In accordance with the OECD "Guidelines for the Testing of Chemicals, Revised Introduction To The OECD Guidelines For Testing Of Chemicals, Section 3 Part I: Principles And Strategies Related To The Testing Of Degradation Of Organic Chemicals" the 10 day window does not apply to UVCB substances ("it is anticipated that a sequential biodegradation of the individual structures is taking place,

then the 10-day window should not be applied to interpret the results of the test").

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-day window (47% at the end of 10 day window; 79% after 28 d)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable but failing 10-day window

Additional information

The biodegradability ot Isotridecyl methacrylate exposed to micro-organisms derived from the activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions according to OECD Guideline 301B.

The biodegradabitity based on CO2 evolution of Isotridecyl methacrylate was calculaled to be 79 % of the theoretical value (ThCO2) atter an incubation time of 28 days. The biodegradation of Isotridecyl methacrylate reached 47 % at the end of the 10-d window. Significant biodegradation of the test substance was observed after a lag phase of about 4 days.

The positive control, sodium benzoate, reached 96 % biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

The calculated biodegradation based on DOC measurement reached 93 % for Isotridecyl methacrylate and 98 % for sodium benzoate.

Isotridecyl methacrylate did not reach the pass level of 60 % for ready biodegradability in the CO2 Evolution Test within the 10 -d window and. therefore, cannot be termed as readily biodegradable. However, the pass level of 60 % was reached after 28 days of incubation.

In accordance with the OECD "Guidelines for the Testing of Chemicals, Revised Introduction To The OECD Guidelines For Testing Of Chemicals, Section 3 Part I: Principles And Strategies Related To The Testing Of Degradation Of Organic Chemicals" the 10 day window does not apply to UVCB substances ("it is anticipated that a sequential biodegradation of the individual structures is taking place,

then the 10-day window should not be applied to interpret the results of the test").

[Type of water: freshwater]