Reaction mass of 2-octyldodecyl 2-hydroxypropanoate, 2-Octyldodecan-1-ol and 2-octyldodecyl 2-[(2-hydroxypropanoyl)oxy]propanoate

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

Study period:

20.04.2016-20.07.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 5-2-A
- Expiration date of the lot/batch: 14. Feb. 2017
- Purity test date: not stated

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: 17 - 23.3 °C, dry conditions, air tight, dark
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: assumed stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: assumed stable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: none
- Preliminary purification step (if any): none
- Final dilution of a dissolved solid, stock liquid or gel: none
- Final preparation of a solid: none

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS:

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Activated sludge from a biologic sewage treatment plant (predominantly domestic).
Date of collection 24. Jun. 2016
Pretreatment: The sludge was filtrated, washed with tap water (2x), then washed with and re-suspended in test medium. It was then aerated until use. The dry matter was determined with 3900 mg suspended solids/L.

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 27.2 mg/L

Based on:

other: organic carbon/L

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium:
KH2PO4, K2HPO4, Na2HPO4, NH4Cl, CaCl2, MgSO4, FeCl3*6H2O, Na2EDTA

- Additional substrate: none
- Solubilising agent (type and concentration if used): none
- Test temperature: 19.4 - 22.0 °C
- pH: for stock solution set to 7.4
- pH adjusted: no
- CEC (meq/100 g): not stated
- Aeration of dilution water: yes
- Suspended solids concentration: mpt stated
- Continuous darkness: not stated
- Other: n/a

TEST SYSTEM
- Culturing apparatus: 2000 ml flask
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: aeration with purified, CO2-scrubbed, moistened air.
- Method used to create anaerobic conditions: n/a
- Measuring equipment: Data logger for temperature, Carbon analyser, pH-meter
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: CO2 trapped in 0.25 M NaOH
- Other:

SAMPLING
- Sampling frequency: on days 0, 2, 4, 7, 9, 11, 14, 18, 23, 29
- Sampling method: 1 mL by pipette, duplicate or triplicate measurement using the carbon analyser
- Sterility check if applicable: no
- Sample storage before analysis: not stated
- Other:

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes
- Other:

STATISTICAL METHODS: none applied

Reference substance:

aniline

Preliminary study:

not performed

Test performance:

Temperature range was 19.4 - 22 °C instead of 20 - 24 °C. As all validity criteria were fulfilled, this deviation is considered as uncritical concerning the outcome of the study.

Parameter:

% degradation (CO2 evolution)

Value:

-0.4

Sampling time:

2 d

Parameter:

% degradation (CO2 evolution)

Value:

0.1

Sampling time:

4 d

Parameter:

% degradation (CO2 evolution)

Value:

4.9

Sampling time:

7 d

Parameter:

% degradation (CO2 evolution)

Value:

20.9

Sampling time:

9 d

Parameter:

% degradation (CO2 evolution)

Value:

35.6

Sampling time:

11 d

Parameter:

% degradation (CO2 evolution)

Value:

42.9

Sampling time:

14 d

Parameter:

% degradation (CO2 evolution)

Value:

54.7

Sampling time:

18 d

Parameter:

% degradation (CO2 evolution)

Value:

65.1

Sampling time:

23 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

75.2

Sampling time:

29 d

Details on results:

Salacos 13 is considered as readily biodegradable.
The degree of biodegradation reached 75 % after 28 days.
The 10-day-window began on day 8, at its end, 55 % degradation were reached, missing the pass level of 60 % given in the OECD guideline.
Because the test item is a Multi-constituent substance and therefore comparable to a mixture, the 1ß-day window has not to be taken into account. Degradation surpassed 60 % within 28 days.
Therefore, the test item is considered as readily biodegradable within 28 days.
Abiotic degradation was not observed.

Validity:

All validity parameters and values are fulfilled:
see table below

Validity results

Parameter	Criterion	Found	Assessment
IC content of test item solution in medium	<= 5 % of TC	0 %	valid
CO2 emitted by the controls	< 70 mg/L	9.7 mg/L	valid
Difference within replicates	<= 20 %	4.7 %	valid
Degradation of positive control	<= 14 days	9 days	valid
Degradation in the toxicity flask on day 14	> 25 %	61 %	valid

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Degradation of Salacos 13 surpasses 60 % within 28 days and the substance can be seen as mixture. Therefore, Salacos 13 is considered as readily biodegradable.

Executive summary:

The test item Salacos 13 was tested using a concentration of nominally 20 mg organic carbon/L

(corresponding to 26.9 mg Salacos 13/L) in test medium following OECD 301B and EU-Method C.4 -C.

Aniline was chosen as positive control. Activated sludge was used as inoculum (concentration in the test

25.0 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 66 % after 9 days.

The following data were determined for the test item Salacos 13:

10 -day-window: day 8 -18

degradation at the end of 10-day-window: 55 %

degradation at the end of the test: 75 %

pass level following guideline: 60 % at the end of 10-day-window for pure substances respective

60 % at the end of the test for mixtures

Because the test item is a Multi-constituent Substance and therefore comparable to a mixture, the 10 -day-window has not to be taken into account. As degradation surpassed 60 % in the course of the test, Salacos 13 is considered as readily biodegradable.

Description of key information

one available Guideline study present

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable