3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Remarks:

Conducted according to guideline in effect at the time of study conduct

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol

EC Number:

211-477-1

EC Name:

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol

Cas Number:

647-42-7

Molecular formula:

C8H5F13O

IUPAC Name:

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol

Details on test material:

- Purity: 99.7%

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
none

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: A test vessel (replicate 4) from each of the blank control and all test concentrations was collected at the study start (day 0) and submitted for analysis. A test vessel (replicate 1) from each of the blank control and test concentrations, and the abiotic control test vessel was collected on day 3 and submitted for analysis.
- Sampling method: LC/MS

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
A stock solution with a nominal concentration of 21 mg/L test substance was prepared by adding approximately 10 μL of test substance to 500 mL of filter-sterilised mAAP nutrient medium. Test solutions with nominal concentrations of 0.20, 0.64, 2.0, and 6.6 mg/L test substance were prepared by diluting aliquots of the nominal 21 mg/L stock solution with filter-sterilised mAAP nutrient medium. Aliquots of the nominal 21 mg/L stock were used for the nominal 21 mg/L test concentration solution and the abiotic control.

Filter-sterilised mAAP nutrient medium was used as the blank control solution. The blank control, stock, and test concentration solutions were clear and colourless with no visible precipitate.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: not reported

ACCLIMATION PERIOD: not reported

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

At the end of the 72-hour exposure period, the blank control and those test concentrations exhibiting a 47% or greater inhibition of healthy cell counts relative to the blank control (mean, measured 7.10 and 23.5 mg/L) were selected for the recovery test.

Each of the blank control and test concentrations was tested as a single vial (no replicates) and was exposed to untreated filter-sterilised mAAP nutrient medium for 7 days without test medium renewal. Recovery test vials were prepared by diluting an approximate 0.5-mL aliquot from a single, randomly selected replicate of the blank control or the combined approximate 0.5-mL aliquots from each of the replicate flasks of the mean, measured 7.10 and 23.5 mg/L concentrations to a total of approximately 44 mL with fresh nutrient medium, resulting in a concentration that theoretically would not inhibit algal growth and growth rate based on visual observations during termination of the definitive test.

Cell counts were determined on days 0, 4, and 7. If cell growth was evident (based on a 16× increase in the number of healthy cells prior to 10 days), the recovery test was terminated and the test substance concluded to be algistatic. If cell growth was not evident, the recovery test was terminated and the test substance concluded to be algicidal.

Test conditions

Hardness:

not reported

Test temperature:

23.8 to 24.0 °C

pH:

7.97 to 9.97

Dissolved oxygen:

not reported

Salinity:

freshwater

Nominal and measured concentrations:

Nominal: 0.200, 0.640, 2.00, 6.60, and 21.0 mg/L
Mean Measured: 0, 0.154, 0.623, 2.22, 7.10, and 23.5 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-mL Erlenmeyer flasks
- Initial cells density: 10000 cells/mL
- Control end cells density: mean 430000 cells/mL
- No. of organisms per vessel: not reported
- No. of vessels per concentration (replicates): 4 (3 used for test, 1 for analytical sample)
- No. of vessels per control (replicates): 4 (3 used for test, 1 for analytical sample)

GROWTH MEDIUM
- Standard medium used: no
- Detailed composition if non-standard medium was used: Synthetic algal-assay-procedure (AAP) nutrient medium, which was modified to contain a higher concentration of sodium bicarbonate to ensure adequate algal growth, was used as the test diluent and blank control and was referred to as mAAP.
To prepare one litre of mAAP nutrient medium, 1 mL of each of the NaNO3, K2HPO4, MgCl2•6H20, MgSO4•7H20, and CaCl2•2H20 macronutrient stock solutions, 5 mL of the NaHCO3 macronutrient stock solution, and 1 mL of the micronutrient stock solution are added to approximately 800 mL of Milli-Q® (deionised) water with mixing after each addition. The final volume of the medium is brought to 1 litre with additional Milli-Q® water. The larger volume required for the definitive test was prepared based on these proportions.
The nutrient medium pH was adjusted to 7.49 with 1.0 N hydrochloric acid and filter-sterilised through 0.22-μm cellulose acetate filters into sterile containers. The containers with the resulting filter-sterilised mAAP nutrient medium were stored in the refrigerator in the dark at approximately 4 °C and acclimated to ambient temperature prior to use.

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: nutrient medium pH was adjusted to 7.49
- Photoperiod: 24 hrs light
- Light intensity and quality: 6670 to 6980 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Growth was determined by counting the number of cells in an approximate 10-μL sample from each vial at approximately 24, 48, and 72 hours after the definitive test initiation. The counts were conducted using a haemocytometer and a compound microscope.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

14.8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence interval 9.85 to 19.8 mg/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

7.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 95% confidence interval 5.16 to 10.3 mg/L

Effect concentrations 3

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

4.52 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: area under the growth curve

Remarks on result:

other: 95% confidence interval 3.49 to 5.87 mg/L

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.22 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: growth rate and cell count

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.623 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: area under the growth curve

Details on results:

- Exponential growth in the control (for algal test): Healthy cell counts increased in the blank control by at least a factor of 16 in 72 hours and the coefficient of variation of average specific growth rates during the whole test period (0-72 hour) in blank control replicates did not exceed 7%, thereby satisfying the appropriate test acceptance criteria.
- Observation of abnormalities (for algal test): not reported

Reported statistics and error estimates:

The following statistical methods were used to evaluate the data: Shapiro-Wilk test, Levene’s test, ANOVA, Jonckheere-Terpstra trend test, Dunnett method, Tamhane-Dunnett, Kruskal-Wallis, Dunn’s test, Tukey outlier rule, Mann-Whitney, Wilcoxon, Bonferonni correction, and regression analysis.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).

0 to 72-hour EbC50 = 7.30 mg/L (cell count) and 4.52 mg/L (area under the growth curve)
72-hr ErC50 = 14.8 mg/L
72-hour NOECs: 2.22 mg/L (growth rate and cell count); 0.623 mg/L (area under the growth curve)

Executive summary:

The toxicity of the test substance to the green algae, Pseudokirchneriella subcapitata was determined in a 72-hr, static toxicity test. The study was conducted with a blank control and 5 concentrations of the test substance at a mean lighting intensity of 6838 lux (range of 6670 to 6980 lux), a mean temperature of 23.9°C (range of 23.8 to 24.0°C), and a shaking speed of 99 rpm. The test was conducted using a zero headspace design. Synthetic algal-assay-procedure nutrient medium, which was modified to contain a higher concentration of sodium bicarbonate to ensure adequate algal growth, was used as the test diluent and blank control and was referred to as mAAP. Test solutions were not renewed. Three replicates were used per test concentration and blank control. A single test vessel was used for the abiotic (stability) control. Healthy cell count, area under the growth curve, and growth rate were determined at 24-hour intervals over the 72-hr test.

 

Inhibition of growth expressed as cell count (density) of Pseudokirchneriella subcapitata exposed to nominal concentrations of 0.20, 0.64, 2.0, 6.6, and 21 mg/L for 72 hours was -5, 2, 9, 47, and 94%, respectively.  Inhibition of growth expressed as area under the growth curve (biomass) was 13, 10, 36, 66, and 98%, respectively. Inhibition of growth expressed as the average specific growth rate was -1, 1, 3, 19, and 78%, respectively. Healthy cell counts increased in the blank control by at least a factor of 16 in 72 hours and the coefficient of variation of average specific growth rates during the whole test period (0-72 hr) in the blank control replicates did not exceed 7%, thereby satisfying the appropriate test acceptance criteria. The mean, measured concentrations of the test substance in the test concentrations and 21 mg/L abiotic control ranged from 77 to 112% of nominal test substance concentrations corrected for 99.7% purity by analysis. 

 

Mean, measured concentrations of the test substance were used for calculation of the EbC50 (72-h), EbC50 (0-72 hr), ErC50 (0-72 hr), LOEC, and NOEC values. The most sensitive parameter was area under the growth curve with a 0-72 hour EbC50 of 4.52 mg/L.

 

The 72-hr LOEC values, based on mean, measured concentrations and percent inhibition of cell count, area under the growth curve, and growth rate, were 7.10, 2.22, and 7.10 mg/L, respectively. The 72-hr NOEC values, based on mean, measured concentrations and percent inhibition of cell count, area under the growth curve, and growth rate, were 2.22, 0.623, and 2.22 mg/L, respectively.

 

Post exposure observation: To assess recovery after the initial 72-hour exposure period, cells from the mean, measured concentrations exhibiting greater than 47% inhibition based on cell count (7.10 and 23.5 mg/L) were placed in nutrient medium without the test substance and counted every 3-4 days for up to 7 days. Recovery data indicated that the effect of the test substance at mean, measured concentrations equal to or below 23.5 mg/L was algistatic.