5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

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:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: according to OECD 301B (Sturm test); experimental part equivalent to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

no

Remarks:

experimental part acc. to GLP standards but no quality control, sample storage and GLP certificate

Test material

Test material information

Constituent 1

Reference substance name:

5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

EC Number:

202-182-9

EC Name:

5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

Cas Number:

92-72-8

Molecular formula:

C19H16ClNO4

IUPAC Name:

N-(5-chloro-2,4-dimethoxyphenyl)-3-hydroxy-2-naphthamide

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Origin of inoculum: municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Source: washed activated sludge of municipal sewage treatment
Preparation of suspension: activated sludge sediment centrifugated twice and resuspended in de-ionized water
Used quantity of inoculum: 10 ml/L suspended sludge
Pretreatment: acc. to guideline; pre-aeration of supernatant for 5 days to deactivate carbon dissolved in activated sludge
Preconditions: not pre-adapted to the test substance and the reference material

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

25.8 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

26.42 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Due to the low solubility of the tested substance no stock solution was prepared. The tested substance was added directly to the test flasks.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

28 d

Details on results:

The value %Degr. is the mean value of two test flasks with two different initial concentrations of the test substance (see section: initial test substance concentration);
The %Degr. value is based on the ratio of determined CO2 formation and the theoretical CO2 formation.
Determinded values were corrected by control values from a blank test performed without any testing substance.
The CO2-evolution of the blank test was below 50 mg/L after 28 days.

BOD5 / COD results

Results with reference substance:

The reference test using benzoic acid sodium salt as reference substance provided a CO2-evolution of more than 60% within 14 days (mean value of 2 tests in 2 test flasks). The %Degr. value is based on the ratio of determined CO2 formation and the theoretical CO2 formation.
The CO2-evolution of the blank test was below 50 mg/L after 28 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item is not (readily) biodegradable.

Executive summary:

The ready biodegradability of Naphtol AS-ITR was tested using a non adapted activated sludge in the CO2 evolution test for a period of 28 days according to OECD guideline 301 B.

No (ready) biodegradation was found (%Degr. = 0)

The validity criteria of the guideline are fulfilled.