Benzoic acid, 4-(methylamino)-3-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:

2011-09-13 to 2011-10-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-(methylamino)-3-nitrobenzoic acid

EC Number:

609-904-5

Cas Number:

41263-74-5

Molecular formula:

C8 H8 N2 O4

IUPAC Name:

4-(methylamino)-3-nitrobenzoic acid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

3.2

Remarks on result:

other: maximum value of biodegradation

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item has showed to be not readily biodegradable under the conditions applied in a Manometric Respirometry test, having not reached the pass level (60% biodegradation), but showing a maximum value of degradation of 3.2% during the test period.
Moreover, the test item showed no inhibitory effects on the microorganism activity at the tested concentration, as demonstrated by the 25% of biodegradation exceeded in the toxicity control, already at the third day of test period.

Executive summary:

The ready biodegradability of the test item BIBR 1048 Aminoacido was assessed in a 28-day biodegradation test following the “Manometric Respirometry” method according to the following guidelines:

OECD guideline for testing of chemicals no. 301F, Ready Biodegradability, Manometric Respirometry test, 1992.

OPPTS 835.3110. Ready Biodegradability. EPA fate, transport and transformation test guidelines, 1996.

Council Regulation EC 440/2008 (C.4 Part V).

For this purpose, the test item was added to activated sludge collected from the aeration tank of a civil wastewater treatment plant and let to stay in contact with the sludge for 28 days under continuous stirring.

The test complies with the validity criteria since the mean oxygen uptake in the inoculum control at the end of test period was 27.5 mg O2/L and there was no difference between duplicate values of test item degradation at the end of the test period (28 days).

Moreover, the reference item reached the biodegradation pass level (60%) on the fourth day (66.0%).

The test item BIBR 1048 Aminoacido was found to be not ready biodegradable under the conditions applied in a Manometric Respirometry test, having showed a maximum biodegradation of 3.2% during the test period (mean percentage values between two replicates).

Even so, the test item did not show any inhibitory effects on the microorganism activity at the tested concentration as demonstrated by the 25% of biodegradation exceeded in the toxicity control already at third day of test period (29.9%).