11-methyldodecyl laurate

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:

July 10th, 2018 - September 14th, 2018

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)

Version / remarks:

OECD 310 – 2014. Ready Biodegradability - CO2 in sealed vessels (Headspace Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, adapted

Details on inoculum:

For the preparation of the inoculum a sample of aerobic sludge has been selected by the mixed treatment plant of urban (about 66%) and industrial (about 34%) liquid sewage situated at San Rocco - Monza (MB), Italia.
In the laboratory, the sampled muds have been mixed and let settle, keeping them in aerobic conditions for 3 days.
The mud samples, before their use, have been analysed to check its ability to form colony units. Then it has been centrifuged, washed and analyzed to quantify the suspended solids concentration for the inoculum preparation. The inoculum was prepared in order to have a concentration of suspended
solid of about 4 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

17.71 mg/L

Based on:

TOC

Remarks:

10 g of the test sample was added to 400 ml of deionised water; it was stirred for 40 minutes at 40°C; it was let settle and the surplus was removed; it was analyzed at TOC analyzer and the value obtained was considered as the initial measured conc.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The inoculum has been added in all bottles, closed and incubation continued under stirring in darkness at 20°C for 28 days. Data recording is performed continuously by a validated informatic monitoring system (Labguard Evisense).
At least 1 hour before every determination of inorganic carbon (TIC) the reaction in one bottle of blank, one of reference substance and one of the test item has been stopped with the addition of 6 ml of
sodium hydroxide (1 M). The concentration of inorganic carbon (TIC) has been measured weekly.

Reference substance:

other: 1-octanol

Key result

Parameter:

% degradation (CO2 evolution)

Value:

10

Sampling time:

1 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

78

Sampling time:

7 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

119

Sampling time:

14 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

109

Sampling time:

21 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

112

Sampling time:

28 d

Details on results:

The mean amount of TIC present in the blank controls at the end of the test is < 3 mg C/L. Abiotic degradation has not occurred because amount of TIC during the test in the abiotic bottles has been lower than 10%.
The trend of the inorganic carbon and related biodegradation percentages in the bottle contained both the test sample and the reference substance (that is 117% after 28 days) confirms the absence of an inhibitory effect of the test sample on inoculum (<25%).

Results with reference substance:

The following results were obtained with the reference substance:
6% at day 1,
80% at day 7,
92% at day 14,
85% at day 21,
81% at day 28.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

On the basis of results obtained, interpreted in accordance with the OECD 301 guideline, 11-METHYLDODECYL LAURATE should be considered readily biodegradable in aerobic conditions.

Executive summary:

On the test item, “11-METHYLDODECYL LAURATE”, the analysis of inorganic carbon for the evaluation in an aqueous medium of the aerobic biodegradability has been performed following screening method described in OECD 310: 2014.

For this purpose the amount of developed inorganic carbon has been measured and reported in comparison to the blank.

The test has been done using the test item with a fixed concentration of organic carbon. Samples have been kept at the temperature of 20°C for the whole period of the test (28 days).

On the basis of results obtained, interpreted in accordance to OECD 310:2014, the test item “11-METHYLDODECYL LAURATE” should be considered readily biodegradable in aerobic conditions.

Description of key information

The substance is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater