6-chloro-5-(2-chloroethyl)-1,3-dihydroindol-2-one

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 November 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: done under GLP and OECD method

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

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)

Principles of method if other than guideline:

Cultures of activated sewage sludge were incubated with synthetic sewage under vigorous aeration and in the presence of the test substance. Aeration was interrupted after three hours and the rates of respiration measured electrochemically for each culture. Percentage inhibition of respiration was calculated for each culture after a three hour contact period by comparing oxygen depletion rates for the test substance with those for the negative control culture. A reference substance, 3,5- dichlorophenol, was tested concurrently with the test substance in order to demonstrate the satisfactory performance of the procedure

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

6-chloro-5-(2-chloroethyl)-1,3-dihydroindol-2-one

EC Number:

421-320-0

EC Name:

6-chloro-5-(2-chloroethyl)-1,3-dihydroindol-2-one

Cas Number:

118289-55-7

Molecular formula:

Hill formula: C10 H9 Cl2 N O CAS formula: C10 H9 Cl2 N O

IUPAC Name:

6-chloro-5-(2-chloroethyl)-2,3-dihydro-1H-indol-2-one

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Expiry: 2 June 1999
Purity: 98.82% by HPLC
Date received: 2 June 1997

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
A reference substance, 3,5- dichlorophenol, was tested concurrently with the test substance in order to demonstrate the satisfactory performance of the procedure.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

A sample of activated sewage sludge was collected from the sewage treatment plant on 29 September ,maintained at 22°C with continuous aeration and used within 24 hours of collection. The pH was 6.7 and the suspended solids level was 4.6 g/1

Test solutions

Vehicle:

yes

Details on test solutions:

A synthetic sewage was prepared by dissolving the following ingredients in one litre of dilution water:
16 g peptone
11g meat extract 3 g urea
0.7 g NaCl
0.4 g CaC12 .2H20
0.2 g MgSO47H20
2.8 g K2HP04

DILUENT WATER
The diluent water was laboratory tap water, dechlorinated by passage through activated carbon and softened by reverse osmosis

REFERENCE SUBSTANCE
3,5-Dichlorophenol (C6H3Cl20H)
Aldrich Chemical Co. Ltd., Batch No.: KQ09615KG, Purity: 97%, Expiry: March 1999.
The reference substance was dissolved in aged, dechlorinated tap water with the aid of ultrasonic disruption.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

NA

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Remarks on exposure duration:

also 30 min

Test conditions

Hardness:

Hardness was approximately 120 - 180 mg/1 as CaC03

Test temperature:

maintained at 22°C

pH:

pH 7.5 ± 0.5).

Nominal and measured concentrations:

Test substance: 100 mg/1 in duplicate.
Reference substance: 3.2, 10 and 32 mg/1.

Details on test conditions:

TEST SYSTEM: series
- Test vessel: 1 liter glass flask
- Aeration: yes
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): NA

test has test substance+synthetic sewage + inoculumn
controls has synthetic sewage + inoculumn only

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The diluent water was laboratory tap water, dechlorinated by passage through activated carbon and softened by reverse osmosis

TEST CONCENTRATIONS
- Test concentrations: Test substance: 100 mg/1 in duplicate. Reference substance: 3.2, 10 and 32 mg/1.

Reference substance (positive control):

yes

Remarks:

3.5 dichlorophenyl

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

not specified

Basis for effect:

growth inhibition

Details on results:

Range finding test- 3 hrs
The validation criteria for (i) Control culture respiration and (ii) respiration inhibition by the reference substance, were fulfilled during this study

Results with reference substance (positive control):

3,5-Dichlorophenol:
EC50 (three hours)± 3% 7 mg/1

Reported statistics and error estimates:

Log-probit analysis with 95% CL.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (respiration inhibition) values for CP-89,575 with activated sewage sludge was> 100 mg/1 for the three hour contact time