3-amino-2,4,6-triiodobenzoic acid

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test)

Deviations:

no

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

3-amino-2,4,6-triiodobenzoic acid

EC Number:

221-493-0

EC Name:

3-amino-2,4,6-triiodobenzoic acid

Cas Number:

3119-15-1

Molecular formula:

C7H4I3NO2

IUPAC Name:

3-amino-2,4,6-triiodobenzoic acid

Test material form:

solid: bulk

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Schering AG, batch no. 37055008

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Municipal sewage treatment plant
- Storage conditions: under aerobic conditions
- Preparation of inoculum for exposure: 1 g of sodium acetate (ref. substance) was dissolved in 1000 mL aqua dest. 1 g of test substance was dissolved in 1000 mL aqua dest. The stock solution of the test substance was analyzed for TOC and for DOC, resulting in 42 mg/L TOC and 43 mg/L DOC repectively.
- Concentration of sludge: The final concentration of hte test and reference sustances was approximately 20 mg DOC in a volume of 1000 mL. In order to reach the final concentration, the following quantities of the different solutions were mixed:
Test substance (ZK2218): 476.2 mL of stock solution, 15 mL nutrient solution, 0.5 mL inoculum, and 508.3 mL aqua dest.
Reference (sodium acetate): 65.9 mL of the stock solution, 15 mL nutrient solution, 0.5 mL inoculum, and 918.6 mL aqua dest.

Duration of test (contact time):

42 d

Initial test substance concentration

Initial conc.:

20 other: mg/1000 mL

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test temperature: 20-25 C
- pH: 7.5 - 7.9
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water: yes
- Continuous darkness: yes
- Other:

TEST SYSTEM
- Culturing apparatus: 2-litre class beakers
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: initial aeration
- Measuring equipment: carbon analyzer
- Test performed in open system: yes

SAMPLING
- Sampling frequency: 1, 2, 5, 8, 15, 22, 28, 29, 36, and 43 days
- Sampling method: carbon analysis was performed by injecting aliquotes of the solution into the carbon analyzer.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 15 mL nutrient solution, 0.5 mL inoculum, and 984.5 mL aqua dest.
- Toxicity control: Toxicity control (ZK2218 + sodium acetate): 65.9 mL of the sodium acetate stock solution, 476.2 mL of the ZK2218 stock solution, 15 mL nutrient solution, 0.5 mL inoculum, and 442.4 mL aqua dest.

Reference substance

Reference substance:

other: sodium acetate

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (DOC removal)

Remarks:

mean of 3 flasks

Value:

21.1

St. dev.:

0.53

Sampling time:

1 d

% Degradation 2

Parameter:

% degradation (DOC removal)

Remarks:

Mean of 3 flasks

Value:

19.47

St. dev.:

0.24

Sampling time:

15 d

% Degradation 3

Parameter:

% degradation (DOC removal)

Remarks:

mean of 3 flasks

Value:

23.56

St. dev.:

0.97

Sampling time:

43 d

% Degradation 4

Parameter:

% degradation (DOC removal)

Remarks:

mean of 3 flasks

Value:

18.41

St. dev.:

1.8

Sampling time:

28 d

Details on results:

The test substance ZK2218 showed no relevant degradation. The final degradation was 0%. The reference compound sodium acetate was degraded to 87% on day 5 (after 4 days of incubation). In the toxicity control, the reference substance, sodium acetate, plus the test substance was degraded up to 60% on day 36 (after 35 days of incubation). The degradation in the toxicity control reflected the degradation observed in the individual sets.

BOD5 / COD results

BOD5 / COD

Remarks on result:

not measured/tested

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance was not readily biodegradable under the test conditions, according to OECD 301E and EU Method C.4B.

Executive summary:

The test substance was not readily biodegradable under the test conditions, according to OECD 301E and EU Method C.4B, which resulted in 21.1%, 19.47%, 18.41%, and 23.56% degradation (DOC removal) at 1, 15, 28, and 43 days, repectively.