2-Propenoic acid, 2-fluoro-, methyl ester

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17/4/15 to 19/6/15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Recently conducted study performed to OECD guideline and under GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 6.25, 12.5, 25, 50 and 100 mg/L
- Sample storage conditions before analysis: Analysed on day of receipt

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: CCAP 278/4
- Source (laboratory, culture collection): Laboratory

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

No data

Test temperature:

24 +/- 1oC

pH:

7.8 - 9.0

Dissolved oxygen:

Not relevant - algae test

Salinity:

No data

Nominal and measured concentrations:

- Nominal concentrations: 6.25, 12.5, 25, 50, 100 and 200 mg/L
- Time-weighted Mean measured concentrations: 3.2, 6.2, 13, 28, 60 and 122 mg/L
- After 72h nominal 6.25, 12.5, 25 and 50 mg/L test solutions observed to be green dispersions
- After 72h nominal 100 and 200 mg/L test solutions observed to be clear, colourless solutions

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass conicial flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 250 mL, no headspace, flasks sealed with ground glass stoppers
- Aeration: None
- Initial cells density: 4.36 x 103 cells/mL
- Control end cells density: 2.72 x 105 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: no
- Detailed composition if non-standard medium was used:
Component Concentration (mg/L)
NaNO3 25.5
MgCl2.6H2O 12.16
CaCl2.2H2O 4.41
MgSO4.7H2O 14.6
K2HPO4 1.044
NaHCO3 15.0
H3BO3 0.186
MnCl2.4H2O 0.415
ZnCl2 0.00327
FeCl3.6H2O 0.160
CoCl2.6H2O 0.00143
Na2MoO4.2H2O 0.00726
CuCl2.2H2O 0.000012
Na2EDTA. 2H2O 0.30
Sodium bicarbonate 500

TEST MEDIUM / WATER PARAMETERS
- Total organic carbon: No data
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine: No data
- Alkalinity: No data
- Ca/mg ratio: No data
- Conductivity: No data
- Culture medium different from test medium: Culture medium did not contain 500 mg/L sodium bicarbonate
- Intervals of water quality measurement: No data

OTHER TEST CONDITIONS
- Adjustment of pH: No data
- Photoperiod: Constant illuminaton
- Light intensity and quality: No data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Electronic particle counter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.0
- Range finding study
- Test concentrations: 0.10, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study:
Nominal concentration (mg/L) Inhibition value (%)
Growth rate Yield
Control - -
0.10 2 -
1.0 3 12
10 2 7
100 47 87

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 59 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 57 - 61 mg/L 95% CI

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 28 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

ca. 60 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 45 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Not possible to calculate 95% CI

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 28 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

ca. 60 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes/no
- Observation of abnormalities (for algal test): Yes
- Unusual cell shape: Yes, no intact cells observed in 60 and 122 mg/L (time-weighted mean measured concentrations)
- Colour differences: No
- Any stimulation of growth found in any treatment: Yes
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test):
- Unusual cell shape:
- Colour differences:
- Flocculation:
- Adherence to test vessels:
- Aggregation of algal cells:
- Other:
- Any stimulation of growth found in any treatment:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:

Reported statistics and error estimates:

- EC50: ECx values determined by Xlfit software package (IDBS),
- 95% confidence intervals: determined by using simplified method of evaluating dose-effect experiments (Litchfield and Wilcoxon, 1949)
- NOEC determined by Dunnett's test

Validity criteria fulfilled:

yes

Conclusions:

The 72 hour EC50 values of the test substance was determined to be 59 mg/L (growth rate) and 45 mg/L (biomass) , based on time-weighted mean measured concentrations.

Executive summary:

The effect of the 2 -propenoic acid, 2 -fluoro, methyl ester on the gorwth of Pseudokirchneriella subcapitata was determined according to OECD guideline 201 over a 72 hour period. The results based on time-weighted mean measured concentrations were:

Response variable	EC50 (mg/L)	95% confidence limits (mg/L)	NOEC (mg/L)	LOEC (mg/L)
Growth rate	59	57 – 61	28	60
Biomass (yield)	45	-	28	60

- Not possible to calculate 95% CI for biomass (yield) data

This study is considered acceptable and meets the guideline requirements for an algae growth inhibiton test

Description of key information

The Key Study reported a 72-hour EC50 (growth rate) toxicity of 2 -propenoic acid, 2 -fluoro, methyl ester to the freshwater green alga Pseudokirchneriella subcapitata of 59 mg/L (95% CI 57 – 61 mg/L) (Vryenhoef, 2015).

Key value for chemical safety assessment

EC50 for freshwater algae:

59 mg/L

EC10 or NOEC for freshwater algae:

28 mg/L

Additional information

The 72-hour toxicity of 2-propenoic acid, 2-fluoro, methyl ester to the freshwater green algaPseudokirchneriella subcapitatawas determined under static test conditions at a temperature of 24±1°C. Based on time-weighted mean measured test solution concentrations the 72-hour EC50 (growth rate) was 59 mg/L (95% CI 57 – 61 mg/L) and the 72-hour EC50 (yield) was 45 mg/L (no 95% CIs). The NOEC for growth rate and yield was 28 mg/L.