Benzoyl chloride, 3-[[[2,3-bis(acetyloxy)propyl]amino]carbonyl]-2,4,6-triiodo-5-[(2-methoxyacetyl)amino]-

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:

Jan - Feb 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 12 May 1981

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

rac-3-(2,3-Diacetoxypropylcarbamoyl)-2,4,6-triiodo-5-methoxyacetylaminobenzoyl chloride

EC Number:

604-759-4

Cas Number:

150928-21-5

Molecular formula:

C18 H18 Cl I3 N2 O8

IUPAC Name:

rac-3-(2,3-Diacetoxypropylcarbamoyl)-2,4,6-triiodo-5-methoxyacetylaminobenzoyl chloride

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

The activated sewage sludge for the inoculum was collected on the day before the start of the experiment from a municipal sewage treatment plant, predominantly dealing with domestic sewage. During the time between collection and use the sewage sludge was kept under aerobic conditions. Approximately 1 hour before the start of the incubation, aeration was discontinued and the sludge was allowed to sediment. The inoculum was obtained from the supernatant.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

The TOC of the stock solution was analyzed by injecting 20 µL for the test compound analysis directly into the carbon analyzer. For the determination of DOC in the stock solution 10 ml were filtrated (0.2 µm) with a filter which does not release any carbon during filtration. The test solutions were analyzed for organic carbon including the reference and the blank. For this purpose 10 mL of each solution were filtrated (0.2 µm) and following filtrate were used for DOC analyses. The carbon analyses were performed by injecting 20 µL of the solutions into the carbon analyzer. Samples from the test solutions for all analyses were taken on days 0, 1, 4, 7, 14, 21, 27 and 28.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 15

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The reference compound sodium acetate was degraded to 100% within 4 days. The test compound was only marginally degraded up to 15%.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Not readily biodegradable: 15% after 28 d

Executive summary:

The test substance ZK 91.445 was incubated in aqueous solutions including nutrients with microorganisms from a municipal sewage treatment plant tor 28 days. The nutrient solution contained phosphates, ammonium chloride, vitamins and trace elements, and was added to the test solution. The test substance ZK 91 .445 was 20 mg/l as dissolved organic carbon (DOC) for each test substance. Additionally, a reference substance (sodium acetate) was tested at the same concentration and according to the same procedure in order to verify the vi ability and activity of the degrading microorganisms. Furthermore, one additional vessel without any test or reference substance was used as blank (control). The biological degradation of the test and reference substances was evaluated by decrease of DOC in the solutions. DOC was analyzed on days 0, 1, 4, 7, 14, 21, 27 and 28.

The test compound ZK 91.445 was not readily biodegradable under the conditions of the test. This does not mean that the compound is not biodegradable, but further investigations would be necessary, if biodegradability has to be established.