3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooct-1-ene

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:

25 - 27 Aug 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The pH of control value increased by more than 1.5 units due to closed vessels.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

yes

Remarks:

pH increased by more than 1.5 units

Qualifier:

according to guideline

Guideline:

other: Algal Growth Inhibition Test stipulated in the "Testing Methods for New Chemical Substances" (November 21, 2003; No. 1121002)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, 100 mg/L

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item was added into the dilution water in an Erlenmeyer flask to produce the 100 mg/L test solution. The flask was immediately sealed with a litle headspace. The solution was stirred by magnetic stirrer for approx. 48 h. After settling for approx. 1 h at 24 ± 1 °C the middle layer of the settled solution was used for testing.
- Eluate: no
- Differential loading: yes
- Controls: yes, test medium control
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No, test solutions were clear and colorless at test start and before renewal.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: ATCC 22662
- Source (laboratory, culture collection): Originally obtained from American Type Culture Collection, USA and maintained in the laboratory since 30 Jun 1995.
- Age of inoculum (at test initiation): 3 d

ACCLIMATION
- Culturing media and conditions (same as test or not): same as test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

22.9 - 23.9 °C

pH:

7.7 - 7.9 (test start)
10.1 (test end)

Nominal and measured concentrations:

nominal: control, 100 mg/L
measured: < LOD, 0.0139 mg/L (geometric mean)

Details on test conditions:

TEST SYSTEM
- Test vessel: 500 mL Erlenmeyer flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 500 mL, headspace: 400 mL, fill volume 100 mL
- Aeration: constantly shaken at 100 rpm
- Initial cells density: 5x10E+03 cells/mL
- Control end cells density: 39E+04 cells/mL (S.D. 4.07E+04 cells/mL)
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, according to guideline

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Culture medium different from test medium: same as test
- Intervals of water quality measurement: The pH of the test solution was measured at test start and end. Temperature and light intensity were measured daily.

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous illumination
- Light intensity and quality: 60 - 120 µE/m²/s; wavelength: 400-700 nm

EFFECT PARAMETERS MEASURED
- Determination of cell concentrations: Coulter counter after 24, 48 and 72 h

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 100 mg/L (test 1); 10, 30 and 100 mg/L (test 2)
- Results used to determine the conditions for the definitive study: 1.69% inhibition after 72 h (test 1); 3.08% inhibition at 10 mg/L, -1.45% inhibition at 30 mg/L, 0.680% inhibition at 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.014 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.014 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: ErC50 (72 h) 1.04 mg/L

Reported statistics and error estimates:

For determination of NOEC an F-test was done to determine the homogeneity of variance for the data followed by a Student t-Test.

Table 1: Measured concentrations of the test item in test solutions

Nominal concentration [mg/L]	Measured concentration [mg/L]
	Test start	24 h	48 h	Test end	Geometric mean
Control	< LOD	< LOD	< LOD	< LOD	-
100 mg/L	0.0712	< LOD	< LOD	< LOD	0.0139

Increase of pH was recorded as a result of no gas exchange between outside and inside the test vessels. Since the growth in the control culture was normal and the validity criteria were met, the increase of pH is not expected to have an impact on the outcome of the study.

The decrease of test concentrations in the test medium is expected to be due to volatilization into the headspace. However, due to constant shaking the algae are expected to be in contact with the test substance in the headspace as well. The measured concentration of 0.0139 mg/L (geometric mean) is still around solubility values determined in this study and the acute fish study (average 0.177 mg/L, variation: 0.151 - 0.223 mg/L and average: 0.101 mg/L, variation: 0.0987 - 0.104 mg/L).

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
The biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72-hour test period.	Increased by a factor of > 63.	yes
The mean coefficient of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3, for 72-hour tests) in the control cultures must not exceed 35%	17.4%	yes
The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 7% in tests with Pseudokirchneriella subcapitata and Desmodesmus subspicatus. For other less frequently tested species, the value should not exceed 10%.	2.56%	yes

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Conclusions:

ErC50 (72 h) > 0.0139 mg/L
NOErC (72 h) ≥ 0.0139 mg/L

Description of key information

ErC50 (72 h) > 100 mg/L (nominal); > 0.0139 mg/L (meas. (geom. mean))
NOErC (72 h) ≥ 100 mg/L (nominal) and ≥ 0.0139 mg/L (meas. (geom. mean))

Additional information

One experimental study is available investigating the effects of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooct-1-ene (CAS 25291-17-2) to freshwater algae (Daikin Industries, 2007). The study was performed according to OECD 201 (GLP) using Pseudokirchneriella subcapitata as test organism. Due to the high vapour pressure of the substance (4640 Pa at 25 °C) it was ensured during preparation of test solutions that the substance does not evaporate from the test medium by avoiding any headspace in the Erlenmeyer flasks and the test vessels. The test solution (limit concentration of 100 mg/L) was prepared by adding an appropriate amount of test substance to dilution water followed by 48 h of stirring and a settling period of 1 h. The middle layer was used for testing. To verify the exposure concentrations analytical measurements using GC/MS were conducted at test start and every 24 h until termination of the study. Since the headspace could not be avoided a decrease from the initial concentration of 0.0712 mg/L to below the analytical detection limit was recorded. However, due to constant shaking the algae are expected to be in contact with the test substance in the headspace as well. The measured concentration of 0.0139 mg/L (geometric mean) is still around solubility values determined in this study and the acute fish study (average 0.177 mg/L, variation: 0.151 - 0.223 mg/L and average: 0.101 mg/L, variation: 0.0987 - 0.104 mg/L). After 72 h no inhibition of growth was observed resulting in an ErC50 of > 100 mg/L (nominal) and > 0.0139 mg/L (meas. (geom. mean)). The NOErC (72 h) was derived to be ≥ 100 mg/L (nominal) and ≥ 0.0139 mg/L (meas. (geom. mean)).