Benzoic acid, 3-[[(2,3-dihydroxypropyl)amino]carbonyl]-5-nitro-

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:

Feb - Mar 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

rac-N-(2,3-Dihydroxypropyl)-5-nitroisophthalamic acid

EC Number:

602-890-1

Cas Number:

122731-58-2

Molecular formula:

C11 H12 N2 O7

IUPAC Name:

rac-N-(2,3-Dihydroxypropyl)-5-nitroisophthalamic acid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Sewage plant Ruhleben
- Laboratory culture: Schering AG
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 an 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

Details on study design:

TEST CONDITIONS
The solutions were incubated first in an incubator in darkness behind trom the 15th test day onwards on a magnetic stirrer with constant stirringin darkness. The temperature was 21 ± 1°C for 28 days.
Sampies from the test and reference solutions for an analyses were taken on days 1, 2, 5, 8, 15,22,28 and 29. The test solutions including the reference and the blank were analysed for dissolved organic carbon. For this purpose 10 mL of each solution were filtered (0.2 µm) and, subsequently, the filtrates were used for DOC-analyses. The carbon analyses were performed by injecting 20 µL of the solutions into the carbon analyser.

Results and discussion

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

13

Sampling time:

28 d

Details on results:

The test compound NIP-Monoamide was degraded up to 11 % on day 22 of incubation when a plateau was reached (with only slight variations thereafter). The reference compound sodium acetate was degraded to 100% on day 5 (4 days of incubation) with subsequent slight variation.

Any other information on results incl. tables

Biological degradation in % (corrected tor blank values)
	Day of sampling
Test compound	1	2	5	8	15	22	28	29
NIP-Monoamide	0	4	7	6	7	11	10	13
Sodium acetate (reference)	0	5	100	96	97	99	101	101
NIP-Monoamide + sodium acetate	0	3	51	49	45	49	51	52

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance NIP-Monoamide attained only 13 % biodegradation within 28 days under the test conditions. Therefore, in accordance with the OECD guideline it can be termed as not readily biodegradable.

Executive summary:

The purpose of this study was to determine the ready biodegradability of the test compound NIP-Monoamide (ZK 39166). The study was conducted in agreement with the test guideline of the OECD, no. 301 E "Modified OECD Screening test" for testing of chemicals; adopted 17. Jul. 92, Paris. The test substance NIP-Monoamide was incubated in aqueous solution including nutrients with microorganisms from a municipal sewage treatment plant for 28 days. The concentration of the test substance was 20 mg/L as dissolved organic carbon (DOC). The test compound was degraded up to 11 % on day 22 of incubation when a plateau was reached (with only slight variations thereafter). The reference compound sodium acetate was degraded to 100% on day 5 (4 days of incubation) with subsequent slight variation. The test substance NIP-Monoamide attained only 13 % biodegradation within 28 days under the test conditions. Therefore, in accordance with the OECD guideline, it can be termed as not readily biodegradable. The results of the toxicity control showed that the expected degradation had been reached. Therefore, no evidence of an inhibiting effect of NIP-Monoamide on the microbial population was found.