Potassium 2-(3-trifluoromethoxy-1,1,2,2,3,3-hexafluoropropoxy)-2,3,3,3-tetrafluoropropionate

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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

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 concentrations

Effect concentrations 1

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

Effect concentrations 2

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.