5-Amino-N,N'-Bis(2,3-Dihydroxypropyl)-2,4,6-Triiodoisophtalamide

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11.11. 2019 – 7.1. 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

474-080-4

EC Name:

-

Cas Number:

76801-93-9

Molecular formula:

C14H18I3N3O6

IUPAC Name:

5-amino-N1,N3-bis(2,3-dihydroxypropyl)-2,4,6-triiodobenzene-1,3-dicarboxamide

impurity 1

Reference substance name:

Unknown impurities

Molecular formula:

Not available

IUPAC Name:

Unknown impurities

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 00104016
- Expiration date of the lot/batch: 12/2020

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store in cool place. Keep container tightly closed in a dry and well-ventilated place.
- Stability under test conditions: Stable

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

INOCULUM
The inoculum contained a mixed population of microorganisms obtained from the secondary effluent of the waste water treatment plant of Pardubice processing predominantly municipal sewage.

PREPARATION OF THE INOCULUM
The fresh collected waste water was filtered through paper filter and aerated till using.

JUSTIFICATION OF THE TEST SYSTEM
The inoculum preparation is in conformity with the recommendations of the test guideline.

Duration of test (contact time):

> 0 - <= 28 d

Initial test substance concentration

Initial conc.:

2.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

PREPARATION OF SOLUTIONS
Inoculated medium: The volume of waste water for the inoculation of mineral medium was chosen 2.1 mL per 1 L of medium. 30 L aerated mineral medium was prepared for the test and before the beginning of the test it was inoculated with 63 mL of modified waste water. The pH value of medium: 7.4.

Test item: The stock solution of the test item was prepared in concentration 0.1001 g·L-1 of deionized water. From this stock solution 150 mL (25 mL·L-1) were transferred to a large glass bottle and completed with the inoculated medium to the volume of 6 L. The solution prepared in this way contained 2.5 mg·L-1 of the test item. The pH value of solution: 7.4.

Reference item: The stock solution of sodium benzoate was prepared in concentration 1.0000 g·L-1 of deionized water. From this solution the 15 mL (2.5 mL·L-1) were transferred to a large glass bottle and completed with the inoculated medium to the volume of 6 L. The solution prepared in this way contained 2.5 mg·L-1 of sodium benzoate. The pH value of solution: 7.5.

Toxicity test: The solution was prepared by dosing 100 mL (25 mL·L-1) of stock solution of the test item and 10 mL (2.5 mL·L-1) of stock solution of the reference item into inoculated medium and completed with this medium to the volume of 4 L. The mixture prepared in this way contained 2.5 mg·L-1 of the test item and 2.5 mg·L-1 of sodium benzoate.

Control (blank) determination: The inoculated mineral medium without test item was used for the blank determination.

TEST CONDITIONS
Temperature: 20 +/- 1.0 °C
Illumination: no illumination, in the dark
Exposition time: 28 days

TEST PROCEDURE
The number of bottles for individual series:
Test item series: 2 x 9 bottles with test item and inoculum
Reference item series: 2 x 9 bottles with reference item and inoculum
Blank series: 2 x 9 bottles with inoculated medium only
Toxicity test series: 2 x 5 bottles with test item, reference item and inoculum for toxicity test
Series for nitrification determination: 1 x 9 bottles with test item and inoculum
The prepared dosing solutions for each series were filled in two parallel bottle replicates (except series for nitrification determination). The bottles were placed into thermostat.

MEASUREMENT
The first two bottles from each series were immediately submitted to analysis for dissolved oxygen (zero-time) and other bottles were placed in the thermostat.
On the 3rd, 7th, 10th, 14th, 17th, 21st, 24th and 28th day of the test, two bottles (parallel replicate) from the test item series, from the reference item series and from the blank series were taken off and the same determination was performed.
On the 3rd, 7th, 10th, 14th day of the test, two bottles from the toxicity test series were taken off and the same determination was performed.
The analysis of dissolved oxygen was performed electrochemically using oximeter device (oximeter WTW OXI 730).

On the 3rd, 7th, 10th, 14th, 17th, 21st, 24th and 28th day of the test, one bottle from the series for nitrification determination was taken off and stored in freezer. The determinations of nitrite-N concentration and nitrate-N concentration were carried out by ion chromatography at one time at the end of the test.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

ThOD of the reference item: 1.665 mg·mg-1

Any other information on results incl. tables

RESULTS EVALUATION

The oxygen consumption and percentage of the biodegradation of the test item for each test interval and each bottle were calculated.

In time intervals when the increase of oxidized nitrogen forms was detected (in interval 17th– 28thday),the correction of oxygen consumption for nitrification was carried out. 

The evaluation of the reference item and of the test and reference item mixture (toxicity test) was done by the same way.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In this 28-day study of ready biological degradability the degradation of 0 % of the test item, ATIBA-A, was attained in the end of study.

Executive summary:

The test item, ATIBA-A, was tested for the ready biological degradability in Closed Bottle Test.

 

Test performance

The test was performed according to:

Method C.4E - Closed Bottle Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008

OECD Test Guideline No. 301 D - Closed Bottle Test. Adopted July 17, 1992

 

The test item was sufficiently soluble in used mineral medium so the dosage from the stock solution was carried out.

Sodium benzoate was used as the reference item.

In parallel to the main test the toxicity test was performed.

Because the test item contains nitrogen in the chemical composition, the oxidized nitrogen forms were determined and the correction for nitrification was carried out.

The test was performed at temperature of 20 ± 1 °C with the pH values of solutions 7 – 8 at the beginning of the test.

The calculations of biological degradation are based on ThOD (theoretical oxygen demand) values of the test and reference item.

Validity of the test

The prescribed validity criteria in the test were fulfilled.

The test item was not inhibiting for the used inoculum.

Since all criteria of acceptability were met, this study is considered to be valid.

Test results

In this 28-day study of ready biological degradability the degradation of 0 % of the test item, ATIBA-A, was attained in the end of study.