[2R[2R*(4R*,8R*)]]-3,4-dihydro-2,8-dimethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 November 1994 - 20 December 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study according to international guideline (OECD 301F) under GLP conditions, validity criteria met.

Data source

Reference

Reference Type:

other: published parts of study report

Title:

Unnamed

Year:

1994

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

EC Number:

233-466-0

EC Name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

Cas Number:

10191-41-0

Molecular formula:

C29H50O2

IUPAC Name:

2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-3,4-dihydro-2H-1-benzopyran-6-ol

Test material form:

liquid: viscous

Specific details on test material used for the study:

- Name of test material (as cited in study report): DL-ALPHA-TOCOPHEROL
- Substance type: Vitamin
- Physical state: Liquid (clear viscous oil)
- Storage condition of test material: 2-8 degrees Celsius, under nitrogen, protected from light (stable for 6 months)

Study design

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): Waste water treatment plant of Füllinsdorf
(Switzerland) receiving domestic sewage
- Preparation of inoculum for exposure: Suspension was stirred and aerated for 24 hours prior to use
- Pretreatment: The sludge was collected from effluent of the plant and immediately aerated. After transportation it was centrifuged and washed two
times. Thereafter the sludge was resuspended in mineral medium.
- Concentration of sludge: 3-5 gram of dry sludge per liter

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

continuous measurement by BOD meter

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

CO2 evolution

Remarks:

CO2 adsorption measured with granular sodium lime

Details on study design:

TEST CONDITIONS
- Composition of medium: 21.75 g K2HPO4/l, 8.50 g KH2PO4/l, 33.40 g Na2HPO4 x 2 H2O/l and 0.50 g NH4Cl/l in deionised water
- Additional substrate: No
- Test temperature: 22 degrees Celsius
- pH: 7.4
- pH adjusted: yes
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Voith Sapromat (automated closed system oxygen measuring apparatus
- Number of culture flasks/concentration: 2
- Measuring equipment: VOITH SAPROMAT oxygen consumption measuring apparatus
- Test performed in closed vessels due to significant volatility of test substance: no; closed system to enable air pressure measurement
- Test performed in open system: No
- Details of trap for CO2 and volatile organics if used: granular sodium line, grain size 2-5 mm.
- Other: an inhibition test was included (test substance + reference substance), to determine a possible toxic effect of the test substance on activated sludge microorganisms.

SAMPLING
- Sampling frequency: Oxygen consumption measured continuously. Reported on day 0, 1, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 21, 22, 25, 26, 27, 28
- Sampling method: BOD-meter measured oxygen consumption continuously
- Sample storage before analysis: No

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: Yes
- Other: Inoculum control with reference substance: Yes

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

Pretests were performed but results are not reported in the study report.

Test performance:

No unusual observations during test.

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

7.79

Sampling time:

28 d

Remarks on result:

other: BOD/ThOD x 100

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

2.06

Sampling time:

21 d

Remarks on result:

other: BOD/ThOD x 100

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

-1.16

Sampling time:

14 d

Remarks on result:

other: BOD/ThOD x 100

% Degradation 4

Parameter:

% degradation (O2 consumption)

Value:

-1.11

Sampling time:

7 d

Remarks on result:

other: BOD/ThOD x 100

% Degradation 5

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

0 d

Remarks on result:

other: BOD/ThOD x 100

BOD5 / COD results

Results with reference substance:

The biodegradation of the reference substance sodium benzoate was 78% after 7 days and 85% at the end of the test. The plateau was reached after 14 days. When the reference substance was incubated in the presence of the test substance, degradation of the reference substance was not inhibited.

Any other information on results incl. tables

Theoretical oxygen demand for Test substance is 1.66 mg/mg (oxidation N to NH4+)

Theoretical oxygen demand for Reference substance sodium benzoate is 3.01 mg/mg (oxidation N to NH4+

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable under the conditions in this test.

Conclusions:

Ready biodegradability of DL-Alpha-Tocopherol was tested according to OECD guideline 301F. The substance was found to show a maximum degradation of 8% after 28 days of testing and thus, is not readily biodegradable under the conditions in this test.

Executive summary:

The ready biodegradability of DL-Alpha-Tocopherol was tested according to OECD Guideline 301F under GLP. Validity criteria of the test were met and the substance was found to show a maximum degradation of 8% after 28 days of testing. Thus, there is no evidence for ready biodegradability of this substance under the conditions in this test. Furthermore it is not toxic to microorganisms of activated sludge.

The product is insoluble in water and can thus be separated from water mechanically in suitable effluent treatment plants.