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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:
24 - 27 Apr 2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
MV31-K-salt
IUPAC Name:
MV31-K-salt
Details on test material:
- Name of test material (as cited in study report): MV31 K-salt, Potassiumperfluoromethoxypropoxypropionate
- Substance type: Pure active substance
- Physical state: solid, grey granules
- Analytical purity: ca. 88 %
- Storage condition of test material: darkness at approximately 20 °C in a fume cupboard

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 20 mL samples were taken form all test solutions at study initiation, and after 24 and 72 hours. Test results appear to be from composite samples.
- Sample storage conditions before analysis: No information

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution prepared by dissolving the substance in deionized water. The chosen test concentration was prepared by adding suitable aliquots to algae pre-cultures.
- Controls: Water blank
- Evidence of undissolved material: None. Test solutions were clear.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name:
- Strain: SAG Strain No. 86.81
- Source: Culture maintained at test laboratory. Origin: Albrecht-von-Haller-Institute for Plant Sciences, Department of Experimental Phycology and Collection of Algal Cultures, University of Gottingen, Germany
- Age of inoculum (at test initiation):
- Method of cultivation: As per Appendix 1 of test guideline

ACCLIMATION
- Acclimation period: No
- Culturing media and conditions: Same as test
- Any deformed or abnormal cells observed: No

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Test temperature:
23.0 - 23.6 °C
pH:
Initial: 7.8 - 7.8. Final: 10.7
Nominal and measured concentrations:
Nominal: 0 mg/L (control), 100 mg/L
Measured: < LOD, 104.6 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: flasks
- Aeration: Stirring or bubbling
- Initial cells density: ca. 10,000 cells/mL
- Control end cells density: 1039000 cells/ml
- No. of vessels per concentration (replicates): three
- No. of vessels per control (replicates): six

GROWTH MEDIUM
- Standard medium used: yes, OECD medium with iron chloride (FeCl3·6(H2O)) increased from 64 mg/L to 80 mg/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: distilled water or deionized water with a conductivity of <5 µS/cm was used to make the growth medium.
OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous illumination
- Light intensity and quality: 6,000 to 10,000 lux.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: cell density in each flask was determined at 24, 48 and 72 hours after the start of the test, using a cell counter.
- Other: algae were observed microscopically at the beginning and at the end of the study. No visible changes of the shape of the algae were noticed either in the control or the treatment groups.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none, limit test

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 4% inhibition
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
(area under growth curve)
Remarks on result:
other: 14% inhibition
Details on results:
- Exponential growth in the control: yes (Table 1)
- Observation of abnormalities: no abnormalities observed, all cells normal
- Any stimulation of growth found in any treatment: no
- Effect concentrations exceeding solubility of substance in test medium: no (Table 2)
Results with reference substance (positive control):
Testing lab does twice-annual testing on potassium dichromate, date and results of most recent test not stated.
Reported statistics and error estimates:
Effects on biomass (as area under growth curve) and growth rate were statistically significant by one-sided t-test (α = 0.05). The NOEC cannot be derived in this test.

Any other information on results incl. tables

Table 1: Individual data from algae inhibition growth test

Concentration (mg)

Cell counts (cells/ mL)

Section specific growth rates (1/day)

Average growth rate (1/day)

24 h

48 h

72 h

0-24 h

24-48 h

48-72h

0

45640

219400

1093667

1.51820

1.59268

1.65350

1.56490

0

46470

211500

1051667

1.53622

1.55601

1.61434

1.55185

0

46407

219800

1083000

1.53487

1.59450

1.64369

1.56164

0

42093

195200

996133

1.43730

1.47581

1.56009

1.53377

0

44453

203967

1004833

1.49185

1.51974

1.56878

1.53666

0

42667

205967

1002033

1.45084

1.52950

1.56599

1.53573

Mean

44622

209306

1038556

1.49488

1.54470

1.60106

1.54742

100

45737

203500

881700

1.52032

1.53704

1.51113

1.49309

100

43950

192200

862900

1.48047

1.47992

1.48958

1.48590

100

41580

187967

828167

1.42503

1.45765

1.44850

1.47221

Mean

43756

194556

857589

1.47527

1.49154

1.48307

1.48373

Mean coefficient of variation for section-by-section specific growth rates: 3.5%

Coefficient of variation of average specific growth rates, 0.9%

Table 2, Concentrations during algae tox test

Sample No.

Nominal concentration

Sampling day

Mean measured concentration (mg/L) ¹

1

0 mg/L (control)

0

<LOD ²

2

0 mg/L

1

<LOD

3

0 mg/L

3

<LOD

4

100 mg/L

0

104

5

100 mg/L

1

103

6

100 mg/L

3

106

1; mean of two determinations

2; LOD, 1 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Control cell density increased by a factor >16 within 3 days. Concentrations of the test substance maintained within 80 % of the initial throughout test.
Conclusions:
The 72-hour EC50 (growth rate) of MV31-K-salt is >100 mg/L (EC method C.3)
Executive summary:

Toxicity of MV31-K-salt was assessed in a limit test done according to EC method C.3. 100 mg/L solutions of MV31-K-salt were tested in triplicate v. 6 controls. A statistically significant (α = 0.5) effect was observed on biomass as area under growth curve among test substance replicates. A 4% effect was observed on growth rate which was statistically significant but not biologically relevant. The 72-hour EC50 of MV31-K-salt is >100 mg/L. The NOEC could not be determined.

The study was conducted under internationally accepted guidelines and was GLP compliant. It is reliable without restrictions and is suitable for Risk Assessment, Classification & Labelling, and PBT Analysis.