2'-ethoxy-3-hydroxy-2-naphthanilide

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

1 (reliable without restriction)

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 209 (Activated Sludge, Respiration Inhibition Test

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2'-ethoxy-3-hydroxy-2-naphthanilide

EC Number:

202-185-5

EC Name:

2'-ethoxy-3-hydroxy-2-naphthanilide

Cas Number:

92-74-0

Molecular formula:

C19H17NO3

IUPAC Name:

N-(2-ethoxyphenyl)-3-hydroxynaphthalene-2-carboxamide

Constituent 2

Reference substance name:

Napthol AS-PH

IUPAC Name:

Napthol AS-PH

Sampling and analysis

Analytical monitoring:

not required

Test solutions

Details on test solutions:

Due to the low solubility of the tested substance no stock solution was prepared. The tested substance was added directly to the test flasks.
Concentration of the tested substance was 500, 1000 mg/L respectively.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Origin: Municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Pretreatment: according to guideline
Preconditions: not pre-adapted to the test chemical and the reference chemical

Study design

Total exposure duration:

3 d

Test conditions

Test temperature:

20°C +/-2

pH:

7.2 +/-0.2 prior to start of test

Reference substance (positive control):

yes

Remarks:

3,5-dichlorphenol at 3 different concentrations (5, 20, 30 mg/L)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

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.

Results with reference substance (positive control):

5 mg/L < EC50 < 30 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The tested substance is not toxic to bacteria in an actived sludge respiration inhibition test. EC50 value amounts to > 1000 mg/L at 3 hours exposure time. Inhibition rate was < 20%.