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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2006/11/20-2006/11/24
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: No amendment to the study plan was requested. No incident, which could have affected the quality or the interpretation of the results obtained, was observed.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
2007/01/12

Test material

Constituent 1
Reference substance name:
MONTANOV 14
IUPAC Name:
MONTANOV 14
Details on test material:
- Batch: T53815
- Appearence: pearls of wax
- Purity: ES>99%
- Stability: water 96h
- Solubility water <0.1 g/L
- Storage: at room temperature 20 +/-5 °C

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
Concentrations: 1 / 10 / 100 mg/L

Test solutions

Vehicle:
no
Details on test solutions:
As the solubility lies below 100mg/L, the water accomodated fraction was prepared for the test. This was done by weighing of each nominal load, adding the corresponding amount of deionised water and shaking vigorously for 24 hours. The resulting solutions were filtrated through 0.45 um filters.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
- Strain: CHODAT
- Source: institut fur Pflanzenphysiologie of Universitât Gôttingen.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Test conditions

Test temperature:
23-25°C
pH:
8.1-8.8
Nominal and measured concentrations:
1 / 10 / 100 mg/L (nominal concentrations)
Details on test conditions:
Experimental conditions:
Lighting: 4440-8880 lux
Control: deionised water with nutrient medium and algae
Treatment: test solution with nutrient medium and algae
Study paramters:
number of replicates: six replicates for the control
three replicates for each treatment

The cell concentration of each replicate was determined by measuring the absorption of the cuvettes at 440 nm avery 24 hours with a spectral photometer.
Reference substance (positive control):
yes
Remarks:
K2Cr2O7

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
ca. 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Results with reference substance (positive control):
NOEC 72h= 0.1 mg/L
LOEC 72h= 0.16mg/L
72h ErC50= 1.1mg/L
72h EbC50=0.36mg/L
72h EyC50= 0.3mg/L
72h ErC100> 1.6 mg/L
72h EbC100> 1.6 mg/L
72h EyC100> 1.6 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
72 h NOEC ca. 100 mg/L
72 h NOEC ca. 100 mg/L
72 h EL50 ca. 100 mg/L
72 h LOEC > 100 mg/L
72 h LOEC > 100 mg/L .
72 h LOEC > 100 mg/L
72 h EC50 > 100 mg/L
72 h EC50 > 100 mg/L
72 h EC50 > 100 mg/L
Executive summary:

The aim of this study is to assess the toxicity of the test item against Desmodesmus subspicatus, an aquatic algae.

This study was conduced in compliance withe OECD guideline n°201 resp EUC.3 and according to the GLP.

As the solubility lies below 100mg/L, the water accomodated fraction was prepared for the test. This was done by weighing of each nominal load, adding the corresponding amount of deionised water and shaking vigorously for 24 hours. The resulting solutions were filtrated through 0.45 um filters.

In the main study, three concentrations of the test item in a geometric series (spaced by factor 10, thye highest being 100mg/L) were used. The treatments were used to incubate the unicellular freshwater green alga Desmodesmus subspicatus for a period of 72 hours.

The cell concentration of each replicate was determined by measuring the absorption of the cuvettes at 440 nm avery 24 hours with a spectral photometer. With these measured values, the number of cells was calculated (linear correlation between cell concentration and aborption given). Then the growth rate, the area under the curve (AUC) and the yield could be determined.

The EC50s of potassium dichromate was tested in a current reference test. The values lay within the normal range of the laboratory.

Conclusion:

72 h NOEC ca. 100 mg/L

72 h NOEC ca. 100 mg/L

72 h EL50 ca. 100 mg/L

72 h LOEC > 100 mg/L

72 h LOEC > 100 mg/L .

72 h LOEC > 100 mg/L

72 h EC50 > 100 mg/L

72 h EC50 > 100 mg/L

72 h EC50 > 100 mg/L