Dipotassium dodecenylsuccinate

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:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dipotassium dodecenylsuccinate

EC Number:

260-612-0

EC Name:

Dipotassium dodecenylsuccinate

Cas Number:

57195-28-5

Molecular formula:

C16H26K2O4*H2O

IUPAC Name:

Dipotassium dodecenylsuccinate

Test material form:

liquid

Details on test material:

30 % aqueous solution
pure substance is solid (bulk/powder), but is only used as aqueous solution and blends it into mixture
Substance dissolves in water at 40wt%, then becomes gel and becomes solid, if mixed 61wt% with water

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Expiration date: 2019-07-27
- Purity test date: Active Ingredient 30%; Water 70%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store in a dark, dry place at room temperature.
- Solubility and stability of the test substance in the solvent/vehicle: in water

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Municipal sewage treatment plant, 31137 Hildesheim, Germany. Activated sludge from the sewage plant at Hildesheim is suited as it receives predominantly municipal sewage and hardly any industrial chemical waste. Receipt: 2017-12-12.
- Preparation of inoculum for exposure:
- Pretreatment: The activated sludge was washed twice with chlorine free tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition by aeration for 2 hours. Thereafter the sludge was homogenized with a blender. After sedimentation the supernatant was decanted and maintained in an aerobic condition by aeration with CO2-free air for 7 days. 15 mL/L were used to initiate inoculation.
- Concentration of sludge:
- Initial cell/biomass concentration: Approx. 10 e7 - 10 e8 CFU/L
- Water filtered: yes

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

92 mg/L

Based on:

test mat.

Remarks:

corresponding to a ThOD of 50.6 mg O2/L per test vessel.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral salts medium according to OECD 301 F
- Test temperature: 20 - 24, ± 1 °C
- pH: 7.69 - 7.76
- pH adjusted: yes
- Continuous darkness: yes

TEST SYSTEM
- Measuring equipment: OxiTop OC110 controller with software Achat OC, WTW; OxiTop measuring heads, WTW; Stirring platform, WTW; Climatic exposure test cabinet, RUMED RUBARTH APPARATE GMBH; pH-Meter, Multi 350i, WTW; Datalogger 174 T, TESTO; Analytical balance, SARTORIUS; Balance, KERN; Magnetic stirrer, MS3000, lab 4 you; Multipette X-Stream, EPPENDORF

CONTROL AND BLANK SYSTEM
- Functional control: sodium benzoate
- Inoculum blank: Test medium without test and / or reference item
- Toxicity control: test and reference item

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

2

Sampling time:

28 d

BOD5 / COD results

BOD5 / COD

Key result

Parameter:

ThOD

Value:

0.55 mg O2/g test mat.

Any other information on results incl. tables

The pass level for ready biodegradation (≥ 60% degradation) was reached within 3 days. The validity criterion that the degradation should be ≥ 60% after 14 d was fulfilled.

Stages of Biodegradation: The adaptation phase changed to degradation phase within 2 days (degradation > 10%), with a maximum of 84% on day 26.

In the toxicity control the biodegradation achieved 47% after 14 days, with 52% after 28 days. The validity criterion that the test item should not inhibit the biodegradation of the reference item was fulfilled.

Both test item replicates did not reachthe 10% level (beginning of biodegradation) within the 28-day-period of the study. The mean biodegradation on day 28 was 2%.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Both test item replicates did not reach the 10% level (beginning of biodegradation) within the 28-day-period of the study. The mean biodegradation on day 28 was 2%.
After a test period of 28 days, the test item is classified as not readily biodegradable within the 28 day period of the study.