Ferrate(4-), hexakis(cyano-C)-, Et 2-[6-(ethylamino)-3-(ethylimino)-2,7-dimethyl-3H-xanthen-9-yl]benzoate copper(2+) salts

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed according to the guideline.

Qualifier:

according to guideline

Guideline:

other: EEC L 133, p. 118-122

Deviations:

yes

Remarks:

Instead a centrifuged sludge a settled sludge was used.

Principles of method if other than guideline:

The inhibitions were calculated on the basis of the measured time depend oxygen consumption of a Blank and Test solution.

GLP compliance:

yes

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

Test system : Activated sludge collected from the sewage treatment plant of CH-4106 Therwil on 16/10/89. The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation.

Test type:

static

Water media type:

freshwater

Total exposure duration:

3 h

Test temperature:

20 ± 2°C

Nominal and measured concentrations:

TEST CONCENTRATIONS
- Test concentrations:
Reference substance : 32, 10 and 3.2 mg/l
Test substance : 100.58, 32.19, 10.1, 3.22 and 1.01 mg/L
The sludge concentration in the test bottles was 1.5 g/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml BOD flasks with gas inlet

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated drinking water

Measurements : Oxygen consumption per hour in mg/liter with a ORION - Electrode Type 97-08, ORION Microprocessor lonalizer 901 and plotted on a recorder.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

15 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Graphically determined

Duration:

3 h

Dose descriptor:

other: IC20

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Graphically determined

Duration:

3 h

Dose descriptor:

other: IC80

Effect conc.:

78 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Graphically determined

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

12 mg/L

Nominal / measured:

nominal

Conc. based on:

other: reference substance

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Graphically determined

Details on results:

The inhibitions were calculated on the basis of the measured time depend oxygen consumption of a Blank and Test solution.

Table: Test result

Sample	Concentration (mg/l)	Consumption rate (mg/l/h)	Inhibition percentage (%)
Blank 1 Blank 2 Reference 1 Reference 2 Reference 3	0.00 0.00 32.00 10.00 3.20	48.75 44.66 7.90 32.03 36.11	-4 4 83 31 23
Test conc. 1 Test conc. 2 Test conc. 3 Test conc. 4 Test conc. 5	100.58 32.19 10.10 3.22 1.01	8.71 12.59 28.22 39.69 43.97	81 73 40 15 6

Validity criteria fulfilled:

not specified

Conclusions:

Toxicity studies to determine the inhibitory concentration of test substance on the respiration of aerobic waste water bacteria were conducted according to EEC L 133, p. 118-122 (30. May 1988) guideline. The test was conducted on activated sludge from a sewage treatment plant for 3 hours at 20°C. The results were graphically determined based on nominal concentrations and IC50 value was determined to be 15 mg/L

Executive summary:

Toxicity studies to determine the inhibitory concentration of test material on the respiration of aerobic waste water bacteria were conducted according to EEC L 133, p. 118-122 (30. May 1988) guideline. The test was conducted on activated sludge from a sewage treatment plant for 3 hours at 20°C. The results were graphically determined . Activated sludge collected from the sewage treatment plant of CH-4106 Therwil on 16/10/89. The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. 3,5-Dichlorophenol was used as referance substance. The inhibitory concentration (IC50) value was determined to be 15 mg/l.

Description of key information

Toxicity to microorganism:

Toxicity studies to determine the inhibitory concentration of test material on the respiration of aerobic waste water bacteria were conducted according to EEC L 133, p. 118-122 (30. May 1988) guideline. The test was conducted on activated sludge from a sewage treatment plant for 3 hours at 20°C. The results were graphically determined . Activated sludge collected from the sewage treatment plant of CH-4106 Therwil on 16/10/89. The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. 3,5-Dichlorophenol was used as referance substance. The inhibitory concentration (IC50) value was determined to be 15 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

15 mg/L

Additional information

Toxicity to microorganism:

Toxicity of test material on microorganism was evaluated using two experimental reports described as follows:

In the first toxicity studies to determine the inhibitory concentration of test material on the respiration of aerobic waste water bacteria were conducted according to EEC L 133, p. 118-122 (30. May 1988) guideline. The test was conducted on activated sludge from a sewage treatment plant for 3 hours at 20°C. The results were graphically determined . Activated sludge collected from the sewage treatment plant of CH-4106 Therwil on 16/10/89. The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. 3,5-Dichlorophenol was used as referance substance.The inhibitory concentration (IC50) value was determined to be 15 mg/l.

Similarly in the second study, respiratory inhibition study ofactivated sludge by test material was conducted according to EC Directive 88/302/EEC - activated sludge: verificationof the inhibition of respiration;corresponds to the OECD Guidelines for Testing of Chemicals 209 and ISO Standard 8192.In the short-term respiration test, the effect of test substance on the respiration of aerobicMicroorganisms (activated sludge) after a short exposure time (30 to 180 min) were investigated.As the test result, the effective concentrations are determined, in which the breathinginhibited relative to a reference value without Priifsubstanz by 20, 50 and 80% (EC20,EC50, EC80).  Effect of the test substance on the respiration of municipal activated sludge were found asEC20: after 30 min about 40 mg / l ,EC50: - After 30 min> 1000 mg /l, respectively.