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Ecotoxicological information

Toxicity to microorganisms

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Reference
Endpoint:
toxicity to microorganisms, other
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Remarks:
Experimental data of test chemical
Justification for type of information:
Experimental data of test chemical is from collection of data
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: Refer below principle
Principles of method if other than guideline:
WoE derived based on the experimental data from various test chemicals to microorganisms
GLP compliance:
no
Analytical monitoring:
not specified
Vehicle:
yes
Details on test solutions:
3rd: Test compound dissolved in distilled water; osmolality adjusted to 2 % NaCl
Test organisms (species):
other: 2nd: Activated sludge, 3rd: Vibrio fisheri
Details on inoculum:
2nd: 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
Remarks on exposure duration:
30 minutes exposure provided in 3rd study
Test temperature:
2nd: 20 ± 2°C
Nominal and measured concentrations:
2nd study:
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:
2nd: 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:
2nd: 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 on result:
other: Graphically determined
Remarks:
2nd study
Duration:
30 min
Dose descriptor:
NOEC
Effect conc.:
6 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
not specified
Remarks on result:
other: EC50 was > 39.9 mg/l
Details on results:
2nd: The inhibitions were calculated on the basis of the measured time depend oxygen consumption of a Blank and Test solution.
Validity criteria fulfilled:
not specified
Conclusions:
2nd: 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 was determined to be 15 mg/L.

3rd: After the exposure period of 30 minutes, chemical have no toxic effects on V. fischeri NRRL B-1117 at the concentration upto 6 mg/L i.e. NOEC (No observed effect concentration) and EC50 was > 39.9 mg/l.
Executive summary:

Summarized result for the toxicity of test chemical were studied and reviewed as mention below:

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 effect concentration (IC50) was determined to be 15 mg/l , Test substance can be concluded to have moderate toxicity on microorganisms.

Similarly according to ISO 11348-2 guidelines toxicity of test compound based on inhibition of luminescence emitted by bacteria was studied and EC50 was determined at 5, 15 and 30 min. After the exposure period of 30 minutes, chemical have no toxic effects on V. fischeri NRRL B-1117 at the concentration upto 6 mg/L i.e. NOEC (No observed effect concentration) and EC50 was > 39.9 mg/l.

Description of key information

2nd: 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 was determined to be 15 mg/L.

3rd: After the exposure period of 30 minutes, chemical have no toxic effects on V. fischeri NRRL B-1117 at the concentration upto 6 mg/L i.e. NOEC (No observed effect concentration) and EC50 was > 39.9 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:
15 mg/L

Additional information

Summarized result for the toxicity of test chemical were studied and reviewed as mention below:

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 reference substance. The effect concentration (IC50) was determined to be 15 mg/l, Test substance can be concluded to have moderate toxicity on microorganisms.

 

Similarly according to ISO 11348-2 guidelines toxicity of test compound based on inhibition of luminescence emitted by bacteria was studied and EC50 was determined at 5, 15 and 30 min. After the exposure period of 30 minutes, chemical have no toxic effects on V. fischeri NRRL B-1117 at the concentration upto 6 mg/L i.e. NOEC (No observed effect concentration) and EC50 was > 39.9 mg/l.