Soybean oil, deodorizer distillate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to guideline testing in compliance with GLP.

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Soybean oil, deodorizer distillate

EC Number:

272-211-8

EC Name:

Soybean oil, deodorizer distillate

Cas Number:

68783-88-0

Molecular formula:

No generic molecular formula is available

IUPAC Name:

Not available for UVCB

Constituent 2

Reference substance name:

'Soybean oil, deodorizer distillates'

IUPAC Name:

'Soybean oil, deodorizer distillates'

Details on test material:

- Name of test material (as cited in study report): 'Soybean oil, deodorizer distillates'
- Substance type: Glycerides, fatty acids and unsaponifiable matter of vegetable origin
- Physical state: Liquid/pasty, brown
- Storage condition of test material: In original container, at room temperature (15 - 25°C), in the dark
- Expiration date of the lot/batch: April 27, 2010
- ThODNH4: 3.053 mg oxygen/mg test item
- ThODN03: 3.059 mg oxygen/mg test item

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal sewage treatment plant (Darmstadt, Germany)
- Preparation of inoculum for exposure: The activated sludge was washed by repeated centrifugation and re-suspension in tap water. The sediment of the last washing was re-suspended in test medium and aerated overnight.
- Concentration of sludge: 1.5 g dry material per L of test medium

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

25 - 25.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: 85 mg KH2PO4, 217.5 mg K2HPO4, 334 mg Na2HPO4 x 2 H2O, 5 mg NH4Cl, 22.5 mg MgSO4 x 7 H2O, 36.4 mg CaCl2 x 2 H2O, 0.25 mg FeCl3 x 6H2O and deionised water up to 1000 mL volume
- Test temperature: 22 ± 1 °C
- pH: 7.4 ± 0.2
- Continuous darkness: Yes
- Other: Continuous stirring of test flasks in climatic chamber


TEST SYSTEM
- Culturing apparatus: Manometric Test System with test flasks containing a volume of approximately 500 mL
- Number of culture flasks/concentration: Duplicate
- Measuring equipment: Pressure decrease (to determine oxygen consumption) measured using BSB Sensomat system, Aqualytic Dortmund
- Test performed in closed vessels : Yes (closed gas-tight by a measuring head)
- Details of trap for CO2 and volatile organics if used: Evolved carbon dioxide was absorbed in an aqueous solution (45%) of potassium hydroxide.


SAMPLING
- Sampling frequency: Day 0 and 28 (for analysis of nitrate and nitrite using ion chromatography)
- Sampling method: Sufficient aliquot was withdrawn from the bottles containing the test item and inoculum, from the inoculum control and from the toxicity control (after measurement of oxygen concentration).
- Sample storage before analysis: ≤-10 °C

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes (Duplicate)
- Abiotic sterile control: Yes (single)
- Toxicity control: Yes (single)
- Other: Procedure control (single)

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

ThOD(NH4): 1.666 mg oxygen per mg

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

54

Sampling time:

28 d

Remarks on result:

other: 10 d window failed

Details on results:

- The oxygen demand of the inoculum control (medium and inoculum) was 30 mg O2/L and thus not greater than 60 mg 02/L within 28 d.

- The difference of the duplicate values for the degradation of the test item and the plateau, at the end of the test and at the end of the 10 d window, was less than 20%

- The test item contains little amounts of nitrogen, therefore the evaluation of biodegradation has to be based on the assumption that nitrification occurred and expressed as ThODNO3.

However, the nitrate concentration in the test item treated vessels was below limit of quantification (LOQ). Therefore, no nitrification occurred.

If no nitrification is considered, the mean biodegradation was also 65% after 28 days of incubation (ThODNH4), still failing the 10-d window.

BOD5 / COD results

Results with reference substance:

The reference substance sodium benzoate was sufficiently degraded to 87% after 14 d and to 90% after 28 d of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

Any other information on results incl. tables

None.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Under the test conditions, the test substanc degraded by 54% within 28 days and was therefore not considered to be readily biodegradable. However an inherent potential for biodegradation was evidenced.

Executive summary:

A study was conducted to determine the ready biodegradability of 'soybean oil, deodorizer distillates' according to OECD Guideline No. 301F and EU Method C4 -D.

The test substance was exposed to aerobic activated sludge from the aeration tank of a domestic waste water treatment plant for 28 d. The biodegradation was followed by the oxygen uptake of the micro organisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

Considering that the test substance contains little nitrogen, the nitrate concentration was measured. However, the nitrate concentration in the test item treated vessels was below LOQ. Therefore, no nitrification occurred.

The reference substance was degraded to more than 60% after 3 d of incubation.

Under the test conditions, the test substanc degraded by 54% within 28 days and was therefore not considered to be readily biodegradable. However an inherent potential for biodegradation was evidenced.