3-hydroxy-2'-methyl-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:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study was carried out according to test guidline and under GLP-conditions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

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:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3-hydroxy-2'-methyl-2-naphthanilide

EC Number:

205-205-0

EC Name:

3-hydroxy-2'-methyl-2-naphthanilide

Cas Number:

135-61-5

Molecular formula:

C18H15NO2

IUPAC Name:

3-hydroxy-N-(2-methylphenyl)naphthalene-2-carboxamide

Constituent 2

Reference substance name:

Naphtol AS-D

IUPAC Name:

Naphtol AS-D

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Origin: Municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Source: supernatant of settled activated sludge
Pretreatment: aeration of supernatant for 3 days using air free of CO2
Used quantity: 10 ml/L
Preconditions: not pre-adapted to the test chemical and the reference chemical

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

32.3 other: mg/3L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

63.4 other: mg/3L

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:

12

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 13.65 mg/L after 28 days.

BOD5 / COD results

Results with reference substance:

The reference test using sodium benzoic acid sodium salt as reference substance provided a degradation of %Deg. = 88% after 28 days (mean value of 2 tests in 2 test flasks). The degradation of the reference substance after 10 days amounted to more than 60%. The %Degr. value is based on the ratio of determined CO2 formation and the theoretical CO2 formation.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: Tested substance is not readily biodegradable (level of 10% degradation exceeded between days 27 and 28)

Conclusions:

The test item must be regarded as not readily biodegradable in the 10-day window and after 28 days.

Executive summary:

The ready biodegradability of the test item 3-hydroxy-N-(2-methylphenyl)-2-naphthamide (Napthol AS-D) was determined with a non adapted activated sludge in the CO2 Evolution Test for a period of 28 days according to OECD guideline 301 B.

Both test item replicates did reach the 10 % level (beginning of biodegradation) only on day 28 (day 27: ca. 6%). After 28 days the biodegradation was 12 % (average of the 2 test items).

The validity criteria of the guideline are fulfilled.

The test item must be regarded as

not readily biodegradable

in the 10-d-window and after 28 days.