Hydrogen trifluoromethoxyborate(1-), compound with methanol (1:1)

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:

key study

Justification for type of information:

see attached justification

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: ATCC-22662
- Source (laboratory, culture collection): National Institute Environmental Research, Korea
- Age of inoculum (at test initiation): 7 days
- Method of cultivation: The flasks then were placed on a shaker incubator at 170 rpm and 25°C, with 24 h light supplied via worm white fluorescent tubes, with an average illumination of 30 ± 5µE/m2s.

ACCLIMATION
- Acclimation period:
- Culturing media and conditions (same as test or not): Stock alga was cultivated in 250 mL Erlenmeyer flasks, containing 200 mL sterilized nitrate-enriched BBM medium prepared in triple distilled water, to avoid nitrogen limitation during the high-density culture. The culture flask was agitated on a shaker at 170 rpm, and bubbled with air (1 vvm), without sparger. Light was continuously supplied, with an average of 30 ±5 µE/m2s, using warm-white fluorescent tubes located on top of the shaker. All the flasks were maintained in the shaker incubator at 25 ± 5°C for 7 days.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

25°C

Details on test conditions:

TEST SYSTEM

Experiments were performed in 250 mL Erlenmeyer flasks containing 55 mL of sterilized culture medium, inoculated with 5 mL samples of 7 day cultured algae. Solutions of organic solvents were subsequently added to the test flasks. The organic solvents tested were completely miscible with water, forming a homogeneous phase. Concentrations were adjusted in the range between 0.1 M and 1.26 µM to obtain complete concentration-response curves. At each determined exposure date, the optical density of the algal biomass was estimated at 438 nm using a spectrophotometer. The dry cell weight, corresponding to the optical density, was determined from the linear relationship; dry cell weight (g/L) = 0.329 x optical density. All experiments were performed in duplicate, but the control experiments were conducted in triplicate.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

ca. 22 000 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth rate

Cross-reference 2

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

from 2004-06-28 to 2005-06-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
A stock solution of the test item diluted in water was prepared one hour before the beginning of the test by mixing 500 mg of boron trifluoride dihydrate in 1 L of dilution water. Volumetric flasks were filled with adequate volumes of the test item stock solution and dilution water in order to obtain the test concetrations.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source: Culture Centre of Algae and Protozoa, Ambleside, UK
- Culture conditions: 23 ± 1 °C, photoperiod 16 h illumination, 8 h darkness, continuous aeration (0.22 µm filter)
- Stock cultures are renewed every two weeks

PRECULTURE
- Period: 4 days prior to test initiation
- Culturing media same as test
- Age of inoculum (at test initiation): 4 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23 ± 1 °C

pH:

7.7 - 9.7

Dissolved oxygen:

8.8 - 9.8 mg/L

Nominal and measured concentrations:

Nominal: 0, 102, 173, 294, 500 mg/L
Recoveries 91 - 100 %

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL erlenmeyer flasks stoppered with cotton wool wrapped in sterilised gauze
- Test volume: 50 mL
- Initial cells density: 10000 cells/mL
- Control end cells density: 1051000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes (C3)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: as described in method C.3. of directive 92/69/EEC
- Culture medium same as test medium
- Intervals of water quality measurement: pH and dissolved oxygen after 0 and 72 h

OTHER TEST CONDITIONS
- Photoperiod: constant illumination

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: using an optical microscope equipped with an haemacytometer (Malassez cell counter), recorded daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7
- Range finding study: 0.1 - 100 mg/L, no effects observed

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 294 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

294 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 294 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

173 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- The increase in cell density (R), measured in the control solution between the beginning and the end of the test, was greater than a factor of 16 (R = 105).
- Microscopic observations confirmed that the algal cells appeared normal at the end of the test

Results with reference substance (positive control):

- ErC50 = 0.93 mg/L; EbC50 = 0.34 mg/L (obtained 07-2004)

Cross-reference 3

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

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

Test type:

static

Limit test:

no

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

35 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: Element/Boron

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

52.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: Element/Boron

Basis for effect:

growth rate

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen trifluoromethoxyborate(1-), compound with methanol (1:1)

EC Number:

220-543-9

EC Name:

Hydrogen trifluoromethoxyborate(1-), compound with methanol (1:1)

Cas Number:

2802-68-8

Molecular formula:

CH4O.CH3BF3O.H

IUPAC Name:

hydrogen trifluoro(methanolato)borate(1-) methanol (1:1)

Details on test material:

Name of the test substance used in the study report: Borfluorid-Methanol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Basis for effect:

growth rate

Remarks on result:

other: Value derived from effect concentrations observed in test with boric acid (value expressed as mg B/L recalculated accounting for molecular weight of the target substance)

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Basis for effect:

growth rate

Remarks on result:

other: Value derived from effect concentrations observed in test with boric acid (value expressed as mg B/L recalculated accounting for molecular weight of the target substance)