Ammonium N-methyl-N-(1-oxododecyl)glycinate

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:

19 Jan - 18 Feb 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

Version / remarks:

17 Jul 1992

Deviations:

yes

Remarks:

The temperature ranged from 19.2 - 21.5 °C instead of 20.0 - 24.0 °C. As degradation of the positive control was in the normal range, this is considered as uncritical.

Qualifier:

according to guideline

Guideline:

EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test)

Version / remarks:

31 May 2008

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Rheinland Pfalz, German (08 Apr 2015)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, NW-Lachen-Speyerdorf, Germany (21 Jan 2016)
- Storage conditions: Aeration until use (after filtration and washing).
- Preparation of inoculum for exposure: The sludge was filtered through a clean cotton cloth, then washed with tap water twice, washed with test medium once and resuspended in test medium. It was then aerated until use in the test.
- Concentration of sludge: Determination of dry matter resulted in 3800 mg suspended solids/L.
- Type and size of filter used, if any: Clean cotton cloth.

Duration of test (contact time):

28 d

Initial conc.:

202.9 mg/L

Based on:

test mat.

Initial conc.:

39.9 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium
- Preparation of test solutions: A stock solution containing 1000.1 mg/L in deionised water was prepared. Its TOC (total organic carbon, determined as total carbon TC minus inorganic carbon IC) and DOC (dissolved organic carbon, TOC after filtration through 0.45 µm filters) were determined in order to estimate the amount to be added to the test flasks. The TOC was 196.74 mg/L, the DOC 194.19 mg/L. Calculated from the content of organic carbon, 50.8 mL were added to the test flasks.
- Test temperature: 19.2 - 21.5 °C
- pH: 7.5
- pH adjusted: Yes.
- Suspended solids concentration (inoculum concentration): 24.9 mg/L
- Continuous darkness: Yes.

TEST SYSTEM
- Culturing apparatus: 500 Erlenmeyer flasks with 250 mL test medium.
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: Aeration of activated sludge.
- Measuring equipment: Carbon analyser TOC multi N/C 2100S, Analytik Jena, Germany
- Other: The test was performed with a start concentration of 39.9 mg organic carbon/L in the test flasks and 40.0 mg organic carbon/L in the positive control flasks.

SAMPLING
- Sampling frequency: From each replicate, 5 samples were taken in order to determine the DOC (after 3 h, 4 d, 8 d, 15 d, and 28 d)
- Sampling method: Each sample was measured in duplicate or triplicate, depending on the variation between single measurements.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 replicates, containing mineral medium and inoculum.
- Abiotic sterile control: 1 replicate, containing test item, mineral medium and HgCl2
- Toxicity control: 1 replicate, containing test item, positive control (aniline), mineral medium and inoculum.
- Positive control: 2 replicates, containing positive control (aniline), mineral medium and inoculum
- Adsorption control: 1 replicate, containing test item, mineral medium, inoculum and HgCl2

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

98.2

Sampling time:

28 d

Details on results:

The 10-d window began on Day 0, at its end, 95% were reached, surpassing the pass level of 70% stated in the OECD guideline. Therefore, the test item can be considered as readily biodegradable.

The validity criteria were met.

The calculated values for the percentage degradation are presented in the following table (Table 1).

 

Table 1. Degradation values in %.

Day	Positive control 1	Positive control 2	Positive control mean	Test 1	Test 2	Test mean	Abiotic control	Adsorption control	Toxicity control
4	76.2	56.0	66.1	80.4	81.8	81.1	-6.4	-5.3	90.6
8	98.5	99.0	98.8	94.1	94.0	94.1	-9.8	-8.9	95.8
15	98.8	98.5	98.7	97.6	97.0	97.3	-9.6	-16.2	98.1
28	98.9	98.7	98.8	98.4	97.9	98.2	-12.3	-21.5	97.5

At the end of the test a slight increase of the measured DOC concentration in the abiotic control could be observed. While in fact no degradation has taken place, negative degradation values were calculated.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The substance is readily biodegradable: 98.2% after 28 d (OECD 301 A/EU C.4-A).

Description of key information

Readily biodegradable: 98.2% in 28 d (OECD 301 A, activated sludge)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

There is one GLP-study available, in which the ready biodegradability of Ammonium N-methyl-N-(1-oxododecyl)glycinate (CAS 68003-46-3) was assessed according to OECD guideline 301 A using domestic activated sludge from a municipal waste water treatment plant.

A nominal concentration of 202.9 mg/L test item, corresponding to 39.9 mg organic carbon/L, was inoculated with 24.9 mg dry matter/L activated sludge for 28 d under aerobic conditions in the dark. An abiotic, an inoculum and a positive control were run in parallel. Degradation was followed by the determination of dissolved organic carbon (DOC) and measurements were taken at frequent intervals.

After 28 d incubation, the test item was degraded by 98.2% and the 10-days window was reached (95% at the end of 10-day window). Therefore, Aammonium N-methyl-N-(1-oxododecyl)glycinate (CAS 68003-46-3) is readily biodegradable according to the OECD guideline criteria.