Bicyclo[3.1.1]hept-2-ene, 2,6,6-trimethyl-, phosphosulfurized

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:

From 12 April 2016 to 15 April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: CCAP 278/4
- Source (laboratory, culture collection): Culture Collection of the Scottish Association for freshwater Science (SAMS).

ACCLIMATION
- Culturing media (same as test or not): Deionised water with added nutrients according to OECD 201
- Temperature: 21.9 – 22.3 °C.
- Illumination: 6120 – 7980 lux continuous white light.
- Orbiting: set to 200 rpm.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

None

Hardness:

No data

Test temperature:

The temperature ranged from 21.2 to 23.0 °C (see attached background material)

pH:

The pH ranged from 7.61 to 8.12 (see attached background material)

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

Nominal concentrations; 0 (control with 6 replicates), 0.1, 0.32, 1.0, 3.2, 10, 32, 100, 320, 1000 mg/L each with 3 replicates

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL conical flask
- Type: open
- Fill volume: 100 mL
- Initial cells density: 1 x 10^4 cells/mL
- Control end cells density: 137.8 x 10^4 cells/mL (mean of 6 replicates)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
See attached background material

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Light intensity and quality: varied from 6100 to 7990 lux (see attached background material)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope and hemocytometer

TEST CONCENTRATIONS
- Range finding study: Yes
- Test concentrations: 0 (control), 0.1, 1.0, 10, 100 mg/L each at one replicate
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.001 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 2.1E-09 – 0.044mg/l

Duration:

48 h

Dose descriptor:

EC20

Effect conc.:

0.04 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 5.2E-06 – 0.507mg/l

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

22.36 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 3.691 – 242.7mg/l

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.723 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 0.226 – 8.804mg/l

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

12.47 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 2.514 – 28.77mg/l

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

168 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: 85.53 – 394.8mg/l

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

Yield

Remarks on result:

other: Determined by Bonferroni t Test

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

13.19 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 0.908 – 38.81mg/l

Duration:

48 h

Dose descriptor:

EC20

Effect conc.:

58.59 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 12.85 – 122.1mg/l

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

749.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 377.3 – 2736mg/l

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

147.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 28.25 – 264.8mg/l

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

340 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 145.7 – 501.6mg/l

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1 417 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 933.5 – 3850mg/l

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Determined by Bonferroni t Test

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none observed
- At 48 hours concentrations 0.1, 0.32, 1.0, 3.2, 10 and 32 mg/L appeared light green in colour, 100mg/l was very light green and 320 and 1000 mg/L clear and colourless. At 72 hours 0.1, 0.32, 1.0, 3.2, 10, 32, 100 and 320 mg/L appeared light green and 1000 mg/L was clear and colourless.

Results with reference substance (positive control):

- Results with reference substance valid
- EC50 was in the range of 0.65 to 1.73 mg/L

Reported statistics and error estimates:

The EC(r)10 and EC(r)50 values with 95 % confidence limits and NOEC(r) were calculated according to the statistical methods of ToxCalcTM Version 5.0 “Comprehensive Toxicity Data Analysis and Database Software”, copyright 1994-1996.

See attached background material.

Validity criteria fulfilled:

yes

Conclusions:

At the end of the 72 hour exposure period to the test substance, the EC50 for growth rate and yield of the test substance to Pseudokirchneriella subcapitata was found to be 1417 mg/L and 168 mg/L respectively.

Executive summary:

The short-term toxicity of the test substance to the fresh water aquatic algae Pseudokirchneriella subcapitata was examined in accordance to the OECD guideline 201. A water accommodated faction was prepared due to the poor solubility of the test item.

A 72 hours toxicity test was performed on a standardized laboratory culture containing ca. 1.0 x 10^4 cells/mL. The nominal concentrations of 0.1, 0.32, 1.0, 3.2, 10, 32, 100, 320 and 1000 mg/L were used during the experiment. The EC50 value was determined using ToxCalcTM Version 5.0 “Comprehensive Toxicity Data Analysis and Database Software”, copyright 1994-1996. The tests were conducted under controlled temperatures at 22 ± 2 °C and static conditions. The test substance showed an EC50 of 1417 and 168 mg/L for growth rate and yield respectively.

Description of key information

The 72 hour toxicity to aquatic algae study of the registered substance showed a dose response relationship.  The EC50 was discovered to be 1417 and 168 mg/L for growth rate and yield respectively for freshwater algae species Pseudokirchnerella subcapitata. 

Key value for chemical safety assessment

EC50 for freshwater algae:

1 417 mg/L

EC10 or NOEC for freshwater algae:

32 mg/L

Additional information

The acute toxicity of registered substance to fresh water algae was determined according to OECD guideline 201. The species of the study was Pseudokirchnerella subcapitata. A 72 hours toxicity test was performed on a standardized laboratory culture containing ca. 1.0 x 10^4 cells/mL. The nominal concentrations of 0.1, 0.32, 1.0, 3.2, 10, 32, 100, 320 and 1000 mg/L were used during the experiment each with 3 replicates. The tests were conducted under controlled temperatures at 22 ± 2°C and static conditions. The EC50 value was determined using ToxCalcTM Version 5.0 “Comprehensive Toxicity Data Analysis and Database Software”, copyright 1994-1996. The registered substance showed an EC50 of 1417 and 168 mg/L for growth rate and yield respectively.