Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

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:
11 March 2010 and 14 April 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Version / remarks:
2006
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Version / remarks:
EC 440/2008
GLP compliance:
yes (incl. QA statement)
Specific details on test material used for the study:
Sponsor's identification: Octafluoropentyl methacrylate
Purity: >99%
Analytical monitoring:
yes
Details on sampling:
Samples were taken from the controls (replicates pooled) and each test group (replicate concentrations pooled) at 0 and 72 hours for quantitative analysis. Duplicate samples were taken at 0 hours and stored at approximately -20°C for further analysis if necessary.

Given the volatile nature of the test item an additional control and test replicate was prepared and incubated alongside the test remaining unopened until the end of the test. A sample of each of these additional test replicates was taken for chemical analysis at 72 hours.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
An amount of test item (1100 mg) was dispersed in 11 L of culture medium with the aid of propeller stirring at approximately 1500 rpm for 24 hours. After 24 hours, the stirring was stopped and any undissolved test item was removed by filtration through a 0.2 μm filter to give a saturated solution. A series of dilutions was made from this saturated solution.
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: CCAP 276/20
- Source: Culture Collection of Algae and Protozoa (CCAP), Dunstaffnage Marine Laboratory, Oban, Argyll, Scotland
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Test temperature:
24 ± 1 °C
pH:
7.7 - 9.4
Nominal and measured concentrations:
Nominal: 1.0, 3.2, 10, 32 and 100% v/v saturated solution (0-hour measured 0.051, 0.17, 0.61, 2.2, and 7.6 mg/L)
Geometric mean measued concentrations: 0.029, 0.054, 0.24, 0.53, 4.9 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 ml glass conical flasks
- Type: closed
- Material, size, headspace, fill volume: completely filled with test preparation
- Initial cells density:
- Control end cells density: 4 x 10³ cells per ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates):6

GROWTH MEDIUM
- Standard medium used: yes using reverse osmosis purified deionised water

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: No
- Photoperiod: continuous illumination
- Light intensity and quality: approximately 7000 lux (380-730 nm)

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: Coulter Multisizer Particle Counter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Range finding study test concentrations: 0.10, 1.0 and 10% v/v
- Results used to determine the conditions for the definitive study: Yes
Reference substance (positive control):
yes
Remarks:
potassium dichromate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
4.4 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.53 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
4.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: Highest concentration tested (100% v/v saturated solution)
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.1 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.53 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
4.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: Highest concentration tested (100% v/v saturated solution)
Details on results:
- Exponential growth in the control: yes
- Observation of abnormalities: There were no abnormalities detected in any of the control or test cultures
- Colour differences: all control and test cultures were observed to be clear colourless solutions
Results with reference substance (positive control):
- Results with reference substance valid? yes
- EC50: 0.49 mg/L
- Other:The results from the positive control with potassium dichromate were within the normal ranges for this reference item.
Reported statistics and error estimates:
One way analysis of variance incorporating Bartlett's test for homogeneity of variance and Dunnett's multiple comparison procedure for comparing several treatments with a control was carried out on the growth rate and yield data after 72 hours for the control and all test concentrations to determine any statistically significant differences between the test and control groups.

The following data show that the cell concentration of the control cultures increased by a factor of 27 after 72 hours. This increase was in line with the OECD Guideline that states the enhancement must be at least by a factor of 16 after 72 hours.

Mean cell density of control at 0 hours: 3.97 x 10³ cells per mL

Mean cell density of control at 72 hours: 1.06 x 10E5 cells per mL

 

The mean coefficient of variation for section by section specific growth rate for the control cultures was 35% and hence satisfied the validation criterion given in the OECD Guideline which states the mean must not exceed 35%.

 

The coefficient of variation for average specific growth rate for the control cultures over the test period (0 - 72 h) was 2% and hence satisfied the validation criterion given in the OECD Guideline which states that this must not exceed 7%.

Validity criteria fulfilled:
yes
Conclusions:
The acute toxicity of the test item to the freshwater invertebrate algae has been investigated and gave a 72-Hour EC50, based on geometric mean measured test concentrations of 4.4 mg/L (growth rate). Correspondingly the No Observed Effect Concentration was 0.53 mg/L and the Lowest Observed Effect concentration was 4.9 mg/L (i.e., a 100% v/v saturated solution).
Executive summary:

A GLP-compliant study according to OECD Guideline 201 was conducted to assess the acute toxicity of octafluoropentyl methacrylate to freshwater algae. Following range-finding tests, Desmodesmus subspicatus was exposed to dilutions of a 100% v/v saturated solution of test item with geometric mean measured concentration of 0.029, 0.054, 0.24, 0.53, and 4.9 mg/L for 72 hours.

The 72-hour lowest observed effect concentration (LOEC) for both growth rate and yield was the 100% v/v saturated solution with a geometric mean measured concentration of 4.9 mg/L. The 72-hour EC50 (growth rate) based on the geometric mean measured test concentrations was 4.4 mg/L and correspondingly the No Observed Effect Concentration was 0.53 mg/L (for both growth rate and yield).

Description of key information

A GLP-compliant study according to OECD Guideline 201 was conducted to assess the acute toxicity of octafluoropentyl methacrylate to freshwater algae. Following range-finding tests, Desmodesmus subspicatus was exposed to dilutions of a 100% v/v saturated solution of test item with geometric mean measured concentration of 0.029, 0.054, 0.24, 0.53, and 4.9 mg/L for 72 hours.

The 72-hour lowest observed effect concentration (LOEC) for both growth rate and yield was the 100% v/v saturated solution with a geometric mean measured concentration of 4.9 mg/L. The 72-hour EC50 (growth rate) based on the geometric mean measured test concentrations was 4.4 mg/L and correspondingly the No Observed Effect Concentration was 0.53 mg/L (for both growth rate and yield).

Key value for chemical safety assessment

EC50 for freshwater algae:
4.4 mg/L
EC10 or NOEC for freshwater algae:
0.53 mg/L

Additional information