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

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study was carried out according to OECD 209

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 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:

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

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 1000 mg/L (2 tests at 1000 mg/L).

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Origin of inoculum: municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Source: activated sludge of municipal sewage treatment
Preparation of suspension: activated sludge sediment centrifugated twice and resuspended.
Used quantity of inoculum: 90 ml/L suspended sludge
Pretreatment: pre-aeration of the inoculum for 1 - 4 days
Preconditions: not pre-adapted to the test substance and the reference material

Study design

Limit test:

yes

Total exposure duration:

3 h

Test conditions

Test temperature:

20.3 - 20.5°C (prior to measurement)

pH:

7.1 - 7.2 (prior to measurement)

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:

other: EC0

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:

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 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

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.