L-Glutamic acid, N-(1-oxododecyl)-, 1,5-dioctadecyl ester

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:

other: OECD and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

807-033-7

EC Number:

807-033-7

IUPAC Name:

807-033-7

Test material form:

solid: flakes

Details on test material:

Identification: Distearyl N-lauroyl- L- glutamate
Appearance/Physical State: white solid
Batch: Test01
Purity: > 98%
Expiry Date: 29 September 2016
Storage Conditions: room temperature in the dark

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms was obtained on 8 december 2014 from aeration stage of the Severn Trent Water Plc sewage treatment plant at Loughborough, leicestershire, UK, which treats predominantly domestic sewage.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The following test preparations were prepared and inoculated in 5 liter test culture vessels each containing 3 liters of solution:
a) An inoculated control, in duplicate, consisting of inoculated mineral medium.
b) The procedure control containing the reference item (sodium benzoate), in duplicate, in inoculated mineral medium to give final concenreation of 10 mg cabon/L.
c) The test item, in duplicate, in inoculated mineral medium to give a final concentration of 10 mg caron/L.
d) The test item plus the reference item in inoculated mineral medium to give a final concentration of 20 mg carbon/L to act as a toxicity control (one vessal only)

Reference substance

Reference substance:

other: sodium benzoate

Results and discussion

Test performance:

The test was carried out in a temperature controlled room at temperatures of between approximately 18 to 24 ℃, in darkness.
The pH of the test preparations was determined on Day o and day 28 prior to acidification with hydrochloric acid.
Samples (2ml) were taken from the first CO2 absorber vessels on days 0,2,6,8,10,14,21,28 and 29. The second absoeber vessels were samples on Days 0 and 29. All samples were analyzed for IC immediately.

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

32

Sampling time:

28 d

Details on results:

The test item attained 32% biodegradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guidance No.301B.

BOD5 / COD results

Results with reference substance:

Sodium benzoate attained 75% biodegradation after 14 days and 89% biodegradation after 28 days thereby confirming the suitability of the inoculum and test conditons.

Any other information on results incl. tables

Validation Criteria:

The total CO2 evolution in the inoclum control vessels on day 28 was 34.82 mg/L and therefore satisfied the validation crirerion given in the OECD test guidelines.

The IC content of the test item suspension in the mineral medium at the start of hte test was below 5% of the TC content and hence satisfied the validation criterion given in the OECD test guidelines.

The difference between the values for CO2 production at the end of the test for the replicate vessels was <20% and hence satisfied the validation criterion given in the OECD test guidelines.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

The test item attained 32% biodegradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guidance No.301B.