potassium {[(2Z)-4-ethoxy-4-oxobut-2-en-2-yl]amino}acetate

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: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

32085-79-3

EC Number:

608-700-3

Cas Number:

32085-79-3

IUPAC Name:

32085-79-3

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

The inoculum employed in the test was activated sludge from the Mari-Ost municipal sewage treatment plant. The sewage sludge taken off on
September 9, 2003 was treated in accordance with standard procedures of the laboratory (SOPs) and the test batches were inoculated with
6 ml/L of inoculum. The content of suspended solids in the test batches was 19.6 mg/L. The content of dry matter in the inoculum used was 3.27 g/L.

Duration of test (contact time):

28 d

Details on study design:

Vessels: 2000 ml conical flasks with loose aluminium foil closure.
Test batches: 2 flasks containing test item and inoculum, 2 flasks without test item, but with inoculum (= blank batches), 2 flasks containing
reference item (Sodium benzoate) and inoculum (= reference batches).
Preparation of the test and reference item stock solution: 0.5009 g test item dissolved in 500 ml deionized water, 0.5001 g reference item
dissolved in 500 ml deionized water
Method: 1.5 L of medium was introduced into 3 L-glass vessels. Parallel, approximately 800 ml of medium were placed in a 1 L graduated cylinder and 80.0 ml of test item- or 60.0 ml of reference item stock solution were added. The same procedure was followed for the inoculum blank batch, but without addition of test or reference item. Finally, inoculum was further added and the solution was made up to 1 L with mineral medium.
The 1 L of test solution resp. reference item solution or blank batch solution prepared in this manner was added to the 1.5 L introduced in
advance and the mixture was stirred thoroughly. From each of these batches, 2 x 1000 ml portions were transferred into 2000 ml conical flasks.
The loosely covered flasks were incubated at 21.0 to 21.1°C in the dark on a mechanical shaker (28 days).
Sampling frequency: 0 and 3 hours, 7, 14, 21, 27 and 28 days

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

0 d

% Degradation 2

Parameter:

% degradation (DOC removal)

Value:

99

Sampling time:

7 d

% Degradation 3

Parameter:

% degradation (DOC removal)

Value:

99

Sampling time:

21 d

% Degradation 4

Parameter:

% degradation (DOC removal)

Value:

101

Sampling time:

28 d

Details on results:

Gly-Dane-salt reached a degree of degradation of 101 % (DOC decrease) in the course of 28 days.

BOD5 / COD results

Results with reference substance:

The reference item Sodium benzoate achieved a degree of degradation of > 70 % in the course of 14 days (here: 100 % after 14 days).

Applicant's summary and conclusion

Conclusions:

Since Gly-Dane-salt is degraded by > 70% within 10 days after the time at which the biodegradation has reached 10%, it is considered to be
" readily biodegradable ".