ethyl N-acetyl-3,5-dinitro-L-tyrosinate

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)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

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)

Test material

Test material information

Constituent 1

Reference substance name:

L-Tyrosine, N-acetyl-3,5-dinitro-, etyhl ester

Cas Number:

29358-99-4

Molecular formula:

C13H15N3O8

IUPAC Name:

L-Tyrosine, N-acetyl-3,5-dinitro-, etyhl ester

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

Activated sludge from a biologic sewage treatment plant was used as inoculum. The cho-sen plant treats mostly domestic sewage.
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, 67435 NW-Lachen-Speyerdorf.
Date of collection: 10. Jan. 2020, batch no: E20200110.
Pre-Treatment
The sludge was filtrated through a cloth, washed with test medium (2x) and re-suspended in test medium. It was then aerated until use. The dry matter was determined to contain 4.96 g of suspended solids/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

TOC

Details on study design:

Inoculum concentration 25.0 mg/L
Temperature 17.8 - 22.1 °C without direct lighting
Duration 28 days

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

29

Sampling time:

28 d

Details on results:

Degradation values in %
Day Positive Control 1 Positive Control 2 Positive Control Mean Test 1 Test 2 Test Mean Abiotic Control Toxicity Control
2 1.7 0.6 1.1 2.3 -0.1 1.1 1.5 1.1
4 5.0 11.7 8.3 4.0 0.9 2.4 2.0 2.7
7 39.6 57.4 48.5 3.4 2.2 2.8 2.0 31.7
9 64.5 65.7 65.1 3.7 5.5 4.6 2.0 38.2
11 74.4 73.9 74.1 4.2 5.5 4.9 1.8 40.4
14 81.5 80.4 80.9 3.2 6.4 4.8 2.0 45.6
18 78.6 81.4 80.0 11.5 10.9 11.2 2.0 50.4
23 82.7 83.9 83.3 24.1 17.6 20.8 2.0 50.5
29 93.0 91.8 92.4 32.3 26.1 29.2 1.0 56.9

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

All validity criteria were met.
Degradation behaviour of positive control and toxicity control was normal. Abiotic degrada-tion reached 1 %. Both replicates of the test item showed good correspondence.
If degradation in the toxicity flask is below 25 % after 14 days, the test item can be consid-ered as toxic towards the inoculum. As degradation in the toxicity flask was 45.6 % after 14 days, the test item can be stated as “not toxic towards the inoculum in a concentration of 43.5 mg/L”.
Ready biodegradability is defined in the guidelines as degradation surpassing 60% within 10 days after reaching a level of 10 %. Therefore, the test item L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester can be considered as “not readily biodegradable”. Degradation missed the pass level of 60 % within 28 days, though. Therefore, the test item is consid-ered as “not ultimately biodegradable within 28 days”, as well.
No observations were made which might cause doubts concerning the validity of the study outcome.
The result of the test can be considered valid.

Executive summary:

The test item L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester was tested using a concentration of nominally 20 mg organic carbon/L L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester 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 surpassed the pass level of 60 % after 8 days.

 

The following data were determined for the test item L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester:

10-day-window:                                                       day 17 – 27
degradation at the end of 10-day-window                           26 %
degradation at the end of the test                                       29 %
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

 

Therefore, when applying the 10-day-window, the test item L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester is not readily biodegradable following OECD 301B and EU C.4-C respectively. As degradation missed the pass level of 60% in the course of the test, L-Tyrosine, N-acetyl-3,5-dinitro-, ethyl ester is considered as not ultimately biodegradable, within 28 days, as well.