Ethanone, 2-chloro-1-(1-chlorocyclopropyl)-

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: 87/302/EEC

Version / remarks:

1988

Deviations:

yes

Remarks:

the activated sludge was not only ventilated but also agitated

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Type: mixed population of aquatic microorganisms (activated sludge)
- Origin: aeration tank of a waste water treatment plant treating predominantly domestic sewage (Wupper area water authority)
- Pretreatment: aeration of the activated sludge; daily feed with synthetic medium
- pH of the suspension before application: 7.6

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

18.9 - 19.3

pH:

7.3 - 7.9

Dissolved oxygen:

Start: 4.9 - 8.0 mg O2/L
End: 2.8 - 7.9 mg O2/L

Nominal and measured concentrations:

- Test substance: 1, 3.1, 10, 31, 100 mg/L
- Test substance concentration in physico-chemical oxygen consumption control: 100 mg/L
- Reference substance: 2.5, 5, 10, 20, 40 mg/L

Details on test conditions:

- Type of application: direct weighing
- Test concentration of the activated sludge: 400 mg/L suspended solids
- Test temperature: 20 ± 2° C
- Incubation time: 3 hours with permanent aeration
A physico-chemical oxygen consumption control is carried out, since some substances·can also consume oxygen by chemical reactivity. In order to be able to tell the difference between physico-chemical oxygen consumption and biological oxygen consumption (respiration), at least the maximum concentration of the test substance is tested without activated sludge.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (Aldrich, purity: 97 %, batch no. 02611ES-202)

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

Toxicity of the reference substance 3.5-Dichlorophenol to bacteria: 3h-EC50 = 8.3 mg/L

Reported statistics and error estimates:

The EC values are determined by statistical methods (probit analysis).

Test substance

Test concentration [mg/L]	Respiratory rate test substance [mg/L*h]	Inhibition [%]
1	30.0	18.5
3.1	27.6	25.0
10	13.5	63.3
31	6.0	83.7
100	2.0	94.6

Validity criteria fulfilled:

yes

Remarks:

respiratory rate of the 2 controls differs less than 15 %; respiratory rate of the controls < 60 mg O2/L·h; EC5o of the reference substance 3.5-dichlorophenol is in the range 5 - 30 mg/L

Conclusions:

For the test substance a 3h-EC50 of 6.3 mg/L towards bacteria was determined.

Executive summary:

This study was designed to assess the toxicity of the test substance to bacteria. The study was conducted according to the Commission Directive 88/302/EEC; Official Journal of the EC L 133 Part C (1988). This test method is in most parts identical with OECD Guideline 209.

The method assesses the effect of a test substance on microorganisms by measuring the respiration rate after 3 h under defined conditions in the presence of different concentrations of the test substance (1, 3.1, 10, 31, 100 mg/L). A physico-chemical oxygen consumption control is carried out, since some substances·can also consume oxygen by chemical reactivity. In order to be able to tell the difference between physico-chemical oxygen consumption and biological oxygen consumption (respiration), at least the maximum concentration of the test substance is tested without activated sludge.

For the test substance a 3h-EC50 of 6.3 mg/L towards bacteria was determined.

A toxicity of the reference substance 3,5 -Dichlorophenol of 3h-EC50: 8.3 mg/L was determined.

Description of key information

This study was designed to assess the toxicity of the test substance to bacteria. The study was conducted according to the Commission Directive 88/302/EEC; Official Journal of the EC L 133 Part C (1988). This test method is in most parts identical with OECD Guideline 209.

The method assesses the effect of a test substance on microorganisms by measuring the respiration rate after 3 h under defined conditions in the presence of different concentrations of the test substance (1, 3.1, 10, 31, 100 mg/L). A physico-chemical oxygen consumption control is carried out, since some substances·can also consume oxygen by chemical reactivity. In order to be able to tell the difference between physico-chemical oxygen consumption and biological oxygen consumption (respiration), at least the maximum concentration of the test substance is tested without activated sludge.

For the test substance a 3h-EC50 of 6.3 mg/L towards bacteria was determined.

A toxicity of the reference substance 3,5 -Dichlorophenol of 3h-EC50: 8.3 mg/L was determined.

Key value for chemical safety assessment

EC50 for microorganisms:

6.3 mg/L