Reaction mass of potassium difluoro{[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate with potassiumfluoride and potassium carbonate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

2009-04-07 until 2009-07-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The experimental study on the supporting substance is guideline-conform under GLP without deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health, 2008-11-12

Test material

Test material information

Constituent 1

Reference substance name:

cC6O4 ammonium salt

IUPAC Name:

cC6O4 ammonium salt

Constituent 2

Reference substance name:

Acetic acid, 2,2-difluoro-2-[[2,2,4,5- tetrafluoro-5-(trifluoromethoxy)-1,3- dioxolan-4-yl]oxy]-, ammonium salt (1:1)

IUPAC Name:

Acetic acid, 2,2-difluoro-2-[[2,2,4,5- tetrafluoro-5-(trifluoromethoxy)-1,3- dioxolan-4-yl]oxy]-, ammonium salt (1:1)

Constituent 3

Reference substance name:

Reaction mass of ammonium difluoro {[(4S,5R)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate, ammonium difluoro {[(4R,5S)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate, ammonium difluoro {[(4S,5S)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate and ammonium difluoro {[(4R,5R)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate

EC Number:

682-238-0

Cas Number:

1190931-27-1

Molecular formula:

C6H4F9NO6

IUPAC Name:

Reaction mass of ammonium difluoro {[(4S,5R)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate, ammonium difluoro {[(4R,5S)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate, ammonium difluoro {[(4S,5S)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate and ammonium difluoro {[(4R,5R)-2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetate

Details on test material:

- Name of test material (as cited in study report):cC6O4
- Molecular formula (if other than submission substance): C6H4F9NO6
- Molecular weight (if other than submission substance): 357
- Smiles notation (if other than submission substance): [NH4+].FC1(F)OC(F)(OC(F)(F)C([O-])=O)C(F)(OC(F)(F)F)O1
- InChl (if other than submission substance): no data
- Structural formula attached as image file (if other than submission substance): see Fig.1 (C6O4 ammonium salt Structural formula)
- Substance type: pure substance in water solution
- Physical state: Liquid, pale yellow
- Analytical purity: Water solution containing 16% active ingredient
- Impurities (identity and concentrations): not reported
- Composition of test material, percentage of components: not reported
- Isomers composition: not reported
- Purity test date: not reported
- Lot/batch No.: 150/28
- Expiration date of the lot/batch: 31-Dec-2020
- Stability under test conditions: not reported
- Storage condition of test material: At room temperature at about 20°C, away from direct sunlight

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
cC6O4 ammonium salt

PHYSICO-CHEMICAL PROPERTIES
- Melting point: 64.6 °C
- Boiling point: > 138 °C (the substance decomposes before boiling)
- Vapour pressure: 0.00000075 hPa at 25 °C
- Water solubility (under test conditions): highly soluble (>= 667 g/L at 21.7 °C)
- log Pow: -0.38 at 22 °C

OTHER PROPERTIES
- Results of test for ready biodegradability: not ready biodegradable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/l of dry salt of test item cC604
- Sampling method: For measurement of the actual concentrations of the test item cC6O4, duplicate samples were taken from the test media of all test concentrations at the start of the test (without algae) and at the end of the test (containing algae). At the same sampling times, duplicate samples were also taken from the control.
- Sample storage conditions before analysis: All samples were stored deep-frozen (at about -20 °C) immediately after sampling.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test medium of the highest nominal test item concentration of 625 mg cC6O4/L was prepared by mixing 312.5 mg of the test item cC6O4 into 500 mL of test water using ultrasonic treatment for 15 minutes and intense stirring for 15 minutes at room temperature. This test medium was diluted with test water to prepare the test media of the lower test concentrations. The test media were prepared just before the start of the test.

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: Strain No. 61.81 SAG
- Source (laboratory, culture collection): Collection of Algal Cultures (SAG, Institute for Plant Physiology, University of Göttingen, Göttingen / Germany). The algae were cultivated at Harlan Laboratories under standardized conditions according to the test guidelines.
- Age of inoculum (at test initiation): An inoculum culture was set up four days before the start of the test.
- Method of cultivation: The algae were cultivated under the test conditions. The inoculum culture was diluted threefold one day before the start of the test to ensure that the algae were in the exponential growth phase when used to inoculate the test solutions.


ACCLIMATION
Not applicable. The algae were cultivated at Harlan Laboratories under standardized conditions according to the test guidelines.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no data

Test conditions

Hardness:

0.24 mmol/L as CaCO3

Test temperature:

The test flasks were incubated in a temperature-controlled water bath at a temperature of 22 °C

pH:

At the start of the test, the pH measured in the treatments was 8.5. At the end of the test, pH values of 8.2 to 8.3 were measured

Dissolved oxygen:

no data; during the test, the test solutions were continuously stirred by magnetic stirrers.

Salinity:

No data, however detailed description of the mineral composition of the test medium is given in the study report.

Nominal and measured concentrations:

The following nominal concentrations of the test item cC6O4 were tested: 6.25, 20, 62.5, 200 and 625 mg cC6O4/L, corresponding to 1.0, 3.2, 10, 32 and 100 mg dry salt cC6O4/L (test item cC6O4 contains 84% water).
The measured concentrations of the test item cC6O4 (calculated based on the measurement of the content of dry salt cC6O4) in the test media of the highest test item concentration of cC6O4 were between 103 and 106% of the nominal values at the start and the end of the test.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 50-mL Erlenmeyer flasks were used per replicate containing 15 mL of test solution.
- Aeration: During the test period, the test water was not aerated.
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): no renewal
- No. of organisms per vessel: The test was started using a nominal algal cell density of 10000 cells/mL.
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: The biomass was determined by fluorescence measurement and is given as relative fluorescence units (x 10^3). At the start of the test, the initial cell density was 10000 algal cells/mL, corresponding to 1.72 x 10^3 relative fluorescence units.


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted test water prepared according to the test guidelines was used for algal cultivation and testing.
- Total organic carbon: no data
- Particulate matter: no data
- Metals: Macro nutrients: Na, K, Ca, Mg; Micro nutrients: B, Mn, Zn, Co, Cu, Mo, Fe (plus EDTA)
- Pesticides: not applicable
- Chlorine: not applicable
- Alkalinity: 0.8 mmol/l
- Ca/Mg ratio: 1:6.3 (mol/mol)
- Conductivity: No data, however detailed description of the mineral composition of the test medium is given in the study report.
- Culture medium different from test medium: no
- Intervals of water quality measurement: samples taken at the start and at the end of the test after 72 hours.


OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: Flasks were illuminated by fluorescent tubes (Philips TLD 36W/840), installed above the test flasks. The test flasks were positioned randomly and repositioned daily.
- Light intensity: The mean measured
light intensity at the level of the test solutions was approximately 7800 Lux (range: 7200 to 8400 Lux, measured at nine places in the experimental area).


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : cell density was measured via Coulter counter; biomass was measured via fluorometric method.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Justification for using less concentrations than requested by guideline: The enlarged spacing factor of 3.2 between the test concentrations was chosen, because according to the results of the range-finding test the concentration-effect relationship was rather flat and, thus, a large concentration range had to be tested.
- Range finding study: The selection of the test concentrations was based on the results of a range-finding test.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Effect concentrations 7

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 8

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none reported
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none reported
- Effect concentrations exceeding solubility of substance in test medium: none reported

Results with reference substance (positive control):

For evaluation of the algal quality and experimental conditions, potassium dichromate is tested as a positive control twice a year to demonstrate satisfactory test conditions. The result of the latest positive control test performed in February 2009 showed that the sensitivity of the test system was within the internal historical range (72-hour EC50 for the growth rate: 1.1 mg/L (study C36893), range of the 72-hour EC50 for the growth rate from 2000 to 2009: 0.71-1.74 mg/L).

Reported statistics and error estimates:

Dunnett’s tests, one-sided, α = 0.05

Any other information on results incl. tables

Tab. 1: Average Growth Rates (μ)

Dry salt cC604 (mg/l)	Average growth rate μ (day-1) and inhibition of μ (Ir)
	0-24 h		0-48 h		0 -72 h
	µ	Ir (%)	µ	Ir (%)	µ	Ir (%)
Control	1.61	0	1.58	0	1.4	0
1.0	1.68	-4.4	1.61	-2.1	1.39	0.4
3.2	1.59	0.9	1.61	-2.1	1.45	-3.7
10	1.53	4.6	1.57	0.9	1.35	3
32	1.53	5.1	1.56	1.4	1.34	4.1
100	1.47	8.6	1.59	-0.5	1.39	0.6

Tab. 2: Average Growth Rates (μ)

Dry salt cC604 (mg/l)	Yield Y (x 103) and inhibition of Y (Iy)
	0-24 h		0-48 h		0 -72 h
	Y	Iy (%)	Y	Iy (%)	Y	Iy (%)
Control	6.9	0	39	0	113.7	0
1.0	7.5	-8.9	41.7	-7.1	110.8	2.6
3.2	6.8	1.8	41.7	-7.0	131.8	-15.9
10	6.3	8.5	37.8	2.9	99	12.9
32	6.2	9.9	37.5	3.7	95.2	16.2
100	5.8	16.3	39.6	-1.6	110.1	3.2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

negative and positive controls valid

Conclusions:

The test item cC6O4 ammonium salt had no significant inhibitory effect on the growth of the algae (average growth rate and yield) during the test period of 72 hours up to and including the highest nominal dry salt concentration of 100 mg cC6O4 ammonium salt/L.
Considering the similarity of chemical structure between F- Diox potassium salt and cC6O4 ammonium salt, it can be concluded that the same degree of toxicity for F- Diox potassium salt is expected.

Executive summary:

In order to evaluate the potential toxicity for aquatic algae of F- Diox potassium salt it was deemed appropriate to use the Read Across approach based on the experimental study performed on cC6O4 ammonium salt by virtue of similarity of chemical structure between F- Diox potassium salt and cC6O4 ammonium salt (CAS no: 1190931-27-1).

F-DIOX potassium salt and cC6O4 ammonium salt are two salts of the same carboxylic acid, they differ only for the cationic part (K+ in F-DIOX potassium salt and NH4+ in cC6O4 ammonium salt). F-DIOX potassium salt readily dissolves in aqueous media and dissociates to the corresponding carboxylic acid in equilibrium with its anion. The dissociation is expected to be similar for F-DIOX potassium salt and cC6O4 ammonium salt.

It is known that a potential significant contributor to the observed aquatic toxicity ofammonium salts of fluorinated carboxylic acids is theun-ionized ammonia present at the equilibrium in the aqueous solution. Therefore the proposed read across can be considered a worse case approach since the cationic part is the potassium salt.

 

The influence of the test item cC6O4 ammonium salt on the growth of the freshwater green algal species Pseudokirchneriella subcapitata was investigated in a 72-hour static test according to the OECD Guideline 201 (2006), the EU Commission Directive 92/69/EEC, C.3 (1992) and the Commission Regulation (EC) No 440/2008, C.3. The nominal concentrations of the test item of 6.25, 20, 62.5, 200 and 625 mg cC6O4 ammonium salt/L, corresponding to 1.0, 3.2, 10, 32 and 100 mg dry salt cC6O4 ammonium salt/L (test item cC6O4 ammonium salt contains 84% water) were tested in parallel with a control. The test item cC6O4 ammonium salt had no significant inhibitory effect on the growth of the algae (average growth rate and yield) during the test period of 72 hours up to and including the highest nominal dry salt cC6O4 ammonium salt concentration of 100 mg/L. The nominal dry salt cC6O4 ammonium salt concentration of 100 mg/L was, therefore, determined to be the 72-hour NOEC. This value might even be higher, but nominal concentrations of dry salt cC6O4 ammonium salt exceeding 100 mg/L were not tested, in accordance with the test guidelines. The 72-hour LOEC was higher than 100 mg dry salt cC6O4/L.

Considering the similarity of chemical structure between F- Diox potassium salt and cC6O4 ammonium salt, for F- DIOX potassium salt is expected the same degree of toxicity on aquatic algae than for cC6O4 ammonium salt. Therefore it can be concluded that F-DIOX potassium salt has no significant inhibitory effect on the growth of the algae up to the concentration of 100 mg dry salt/L.