4,4'-[(1,10-dioxodecane-1,10-diyl)bis(oxy)]bis(2,2,6,6-tetramethylpiperidine-1-oxidanyl)

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

12 May 1981

Deviations:

yes

Remarks:

The volume of the test solution was reduced from 3 L to 1.5 L. Due to the poor solubility of the test substance in water, an emulsifier was used. The test substance was added directly into the medium without preparing a stock solution.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,10-bis(2,2,6,6-tetramethyl-1-piperidinyloxy)-1,10-dioxodecane

EC Number:

417-440-8

EC Name:

1,10-bis(2,2,6,6-tetramethyl-1-piperidinyloxy)-1,10-dioxodecane

Cas Number:

2516-92-9

Molecular formula:

C28 H50 N2 O6

IUPAC Name:

bis(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) decanedioate

Details on test material:

Identification code (lab) = TKA 40075

Specific details on test material used for the study:

Identification code: TKA 40075

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge collected from the sewage treatment plant of CH-4153 Reinach on 28/06/93.
The preparation was carried out according to the method described in the guideline.

Duration of test (contact time):

29 d

Initial test substance concentration

Initial conc.:

>= 10.8 - <= 20.7 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: The test medium was prepared according to the method described in the guideline.
- Test temperature: 22 +- 2°C
- pH: 7.3
- pH adjusted: no
- Other:
1200 ml of the mineral solution containing the mineral salts for 1500 ml with the inoculum were aerated over night in the test vessel. In 300 ml bidistilled water 15 ml Polyoxyethylen-Sorbitan-Monooleate (TWEEN 80) (FLUKA 93781) (solution of 300 mg in 1000 ml bidistilled water ) and 16.2 rsp. 31.1 mg of test substance were added and homogenized. This mixture was given to the test vessel wich was immediately connected to the CO2 traps.

TEST SYSTEM
- Culturing apparatus: 2 Liter flasks (dark brown glass) equipped with gas inlet and magnetic stirrer.
- Number of culture flasks/concentration: 1
- Details of trap for CO2 and volatile organics if used:
Air: approx. 25 ml/min purified from carbon dioxide.
Scrubbers: approx 250 ml scrubbers with gas inlet tubes equipped with sintered glass tips containing 200 ml 0.05 N sodium hydroxide.

SAMPLING
Determination of the CO2 content in the 0.05 N NaOH solution as inorganic Carbon on a carbon analyzer on the days 0, 3, 6, 8, 10, 15, 20, 24, 28 and 29.

CONTROL AND BLANK SYSTEM
- Inoculum blank:
Water with inoculum containing 3 mg of the Polyoxyethylen-Sorbitan-Monooleate (TWEEN 80) (FLUKA 93781) per liter

Reference substance

Reference substance:

other: Sodium benzoate (MERCK No.: 6290)

Results and discussion

Test performance:

The negative degradation values are within the variation of the method.

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

>= 17 - <= 19

Sampling time:

29 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

TKA 40075 is not biodegradable according to the OECD 301B test.

Executive summary:

Study: Determination of the biodegradability by measurement of the carbon dioxide formation in percent of ThC02 (Theoretical carbon dioxide) calculated from the ThOC (Theoretical organic carbon) or TOC (Total organic carbon).

Test system : Activated sludge collected from a sewage treatment plant.

Duration: 29 days

Guideline: OECD - Guideline No.: 301 B ( 12. May 1981 )

Deviations: The volume of the test solution was reduced from 3.0 1 to 1.5 1. Due to the poor solubility of the test substance in water an emulsifier was used to achieve a better distribution in the medium. The test substance was added directly into the medium without preparing a stock solution.

Results: The biodegradation calculated as percentage of measured amount of carbondioxide over the theory was :

10.8 mg test substance/1 = 17 % in 29 days

20.7 mg test substanee/1 = 19 % in 29 days

Conclusion : TKA 40075 is not biodegradable in this test