Barium(2+) 12-hydroxyoctadecanoate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2019-01-22 to 2019-01-25

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:

28 July 2011

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

01 March 2016

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: Lab NP_20171034-003
- Expiration date of the lot/batch: 2022-07-24

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

OTHER SPECIFICS:
white solid

Analytical monitoring:

yes

Details on sampling:

Test item concentrations were determined at the start and at the end of the test. At the start three replicate samples were analysed from the test solutions and three samples were analysed from the control solution. At the end three replicate samples were analysed from the test solutions and six samples were analysed from the control solution.

Vehicle:

no

Details on test solutions:

The test solutions used in the test were prepared by mechanical dispersion without using of any solubilising agent.
The test item is poorly water soluble. For preparation of the test solution a supersaturated solution (100 mg/L nominal loading) was first prepared by dispersing/dissolving an amount of 0.1 g test item in 1000 mL dilution water (OECD Medium). This solution was agitated by orbital shaker (~350 rpm) for a period of approx. 4 days and then the non-dissolved test material was separated by filtration through a membrane filter (0.45 μm) in order to obtain the saturated test solution. The test solutions of subsequent lower test concentrations were prepared by appropriate dilution of this stock solution. Untreated control ran parallel in the test.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: 61.81 SAG
- Source: Collection of Algal Cultures, Inst. Plant Physiology, University of Göttingen, Untere Karspüle 2, D-37073 Göttingen, Germany

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

in the flasks: 22.4 – 22.8 °C
within the climate chamber: 21.4 - 23.6 °C

pH:

7.62 – 9.34

Nominal and measured concentrations:

Nominal concentrations: 9.5, 17.1, 30.9, 55.6 and 100.0 % v/v saturated solution
Measured concentrations: 1.4, 2.7, 4.9, 9.3 and 17.2 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Material, size, headspace, fill volume: glass, ~250 mL volume, 100 mL test medium
- Initial cell density: ca. 1E+4 cells/mL
- No. of organisms per vessel: 0.10 mL algal biomass (1E+7 algal cells per mL)
- No. of vessels per concentration (replicates): 3
- No. of vessels of control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: OECD Medium prepared according to OECD 201

OTHER TEST CONDITIONS:
- Adjustment of pH: no
- Photoperiod: continuously illuminated
- Light intensity and quality: 7684 lux, fluorescent lamps (range: 400 - 700 nm)

EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: microscope with counting chamber at 24, 48 and 72 hours

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 17.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

8.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.9 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.:

2.7 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

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

6.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

3.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

2.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Results with reference substance (positive control):

The date of the last study with the reference item Potassium dichromate was: 11 – 14 March 2019.
The following results were obtained:
The 72h ErC50: 0.83 mg/L (95 % confidence limits: could not be calculated)
The 72h EyC50: 0.57 mg/L, (95 % confidence limits: 0.45 – 0.72 mg/L)

Pre-Experiments

A non-GLP preliminary experiment was carried out at the saturation concentration to determine the approximate toxicity of the test item.

For preparation of the test solution a supersaturated solution (100 mg/L nominal loading) was prepared by dispersing/dissolving an amount of 0.03 g test item in 300 mL OECD medium. This solution was agitated by orbital shaker for a period of 2 days and then the non-dissolved test material was separated by filtration through a fine (0.22 μm) membrane filter in order to obtain the saturated test solution (corresponding to 100 mg/L nominal concentration).

Algal cells were exposed to the treatment group plus a control, for 72 hours. The test was performed with three replicates in the treatment as well as in the control group.

The preliminary range-finding test was not performed in compliance with the GLP-Regulations and are excluded from the Statement of Compliance (Statement of the Study Director), but the raw data of these tests will be archived under the study code of present study.

Table 1: Results of the preliminary test

Test Group	Control	Saturated test item solution (100 mg/L nom. conc.)
Average of cell number at 72 hours (x 10^4cells/mL)	112.33	108.67
Growth Rates (μ) [0-72h]	0.0655	0.0651
% Inhibition of μ [0-72h]	–	0.6
Yield (Y) [0-72h]	111.33	107.67
% Inhibition of Y [0-72h]	–	3.3

Main study - limit test

Based on the results of this preliminary range-finding test a main experiment (limit study) was performed using a single concentration at saturation (equivalent to 100 mg/L nominal concentration) plus a control.

Table 2: Results of the main experiment (limit test)

Test Group	Control	Saturated test item solution (100 mg/L nom. conc.)
EC10 (95 % conf. limits)	4.9 (4.3 - 5.5)	2.1 (1.5 - 2.7)
EC20 (95 % conf. limits)	8.1 (7.3 - 8.9)	3.2 (2.5 - 3.8)
EC50 (95 % conf. limits)	> 17.2 (calc. 20.7) (18.0 - 24.6)	6.8 (5.8 - 8.1)
NOEC	2.7	1.4
LOEC	4.9	2.7

The results of the main experiment (study no.: 674-201-3198) contradicted with the results obtained in the non-GLP preliminary range-finding test as 100 % growth inhibition was observed in the main test. Therefore the main experiment was repeated (study number 674-201-3198R).

Although the 100 % inhibition of algal growth observed in the test to be repeated was considered to be mainly due to technical issue, the experiment was repeated in a full test using a range of concentrations.

Main study - full test

The following nominal concentrations were tested: 9.5, 17.1, 30.9, 55.6 and 100.0 % v/v saturated solution. Untreated control ran parallel in the test.

The corresponding calculated geometric mean concentrations were the followings: 1.4, 2.7, 4.9, 9.3 and 17.2 mg/L.

Table 3: Results of the main experiment (full test)

Endpoints (0 -72h)	Growth rate µ	Saturated test item solution (100 mg/L nom. conc.)
Average of cell number at 72 hours (x 10^4cells/mL)	63.17	1.00
Growth Rates (μ) [0-72h]	0.0574	0.0000
% Inhibition of μ [0-72h]	–	100.0
Yield (Y) [0-72h]	62.2	0.0
% Inhibition of Y [0-72h]	–	100.0

Validity criteria fulfilled:

yes

Conclusions:

The 72h-EC10 and 72h-EC50 based on growth rate were determiend to be 4.9 mg/L and > 17.2 mg/L (calc: 20.7 mg/L), respectively. The NOEC based on growth rate was determined to be 2.7 mg/L

Executive summary:

The effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata was determined according to OECD 201 and Regulation (EC) No. 266/2016 Method C.3 under GLP. The study was conducted under static conditions with an initial cell density of 1E4 cells/mL for a period of 72 hours. Nominal concentrations of 9.5, 17.1, 30.9, 55.6 and 100.0 % v/v saturated solution corresponding to calculated geometric mean concentrations were the followings: 1.4, 2.7, 4.9, 9.3 and 17.2 mg/L and control was performed. The obtained results showed that the test item had significant toxic effects on the growth of Raphidocelis subcapitata. All validity criteria were met. The results are based on measured geometric mean test item concentrations. The EC50-values for inhibition of growth rate (ErC50) and for inhibition of yield (EyC50) were determined to be >17.2 and 6.8 mg/L, respectively. The ErC10 and EyC10 values were determined to be 4.9 and 2.1 mg/L, respectively. The NOEC for inhibition of growth rate and for inhibition of yield were determined to be 2.7 and 1.4 mg/L, resepctively. The test item showed a significant toxic effect on the green unicellular algae.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 2018-12-11 to 2018-12-14

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:

28 July 2011

Deviations:

yes

Remarks:

no final report

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

01 March 2016

Deviations:

yes

Remarks:

no final report

GLP compliance:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: Lab NP_20171034-003
- Expiration date of the lot/batch: 2022-07-24

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

OTHER SPECIFICS:
white solid

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

A stock solution of 100 mg/L (nominal concentration) was prepared by dissolving 0.08 g of test item in 808 mL OECD Medium. The pH value (5.68) of the stock solution was adjusted to the pH of the OECD Medium - 7.87 (according to OECD 23). The adjusted pH level of the stock solution was 8.14. Further test solutions were prepared by appropriate dilution of this stock solution.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: 61.81 SAG
- Source: Collection of Algal Cultures, Inst. Plant Physiology, University of Göttingen, Untere Karspüle 2, D-37073 Göttingen, Germany
- Age of inoculum (at test initiation): 3 days

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Material, size, headspace, fill volume: glass, ~250 mL volume, 100 mL test medium

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: OECD Medium prepared according to OECD 201

EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: microscope with counting chamber at 24, 48 and 72 hours

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Duration:

72 h

Dose descriptor:

EC50

Remarks on result:

not determinable because of methodological limitations

Details on results:

Very few number of algal cells were found in the test item concentration during the main test (i.e 100% growth inhibition compared to the control).

Table 1: Biological results

Test group	Untreated control	Saturated test iem solution
Average of cell number at 72 hours (x 10^4cells/mL)	63.17	1.00
Growth Rates (µ) [0-72h]	0.0574	0.0
% Inhibition of µ [0-72h]	-	100
Yield (Y) [0-72h]	62.2	0.0
% Inhibition of Y [0-72h]	-	100.0

Validity criteria fulfilled:

not applicable

Conclusions:

The results of the main experiment contradicted with the results obtained in the non-GLP preliminary range-finding test. Very few number of algal cells were found in the test item concentration during the main test (i.e 100% growth inhibition compared to the control). This can be considered to be due to technical issue. The test was repeated under a new study number: 674-201-3198R.

Description of key information

In a 72-hour static acute toxicity test the unicellular green algal species Raphidocelis subcapitata was exposed to the test item at nominal concentrations of 9.5, 17.1, 30.9, 55.6 and 100.0 % v/v saturated solution corresponding to calculated geometric mean concentrations of 1.4, 2.7, 4.9, 9.3 and 17.2 mg/L, respectively. The EC50 growth rate (ErC50) was determined to be >17.2 mg/L, the EC10 growth rate (ErC10) to be 4.9 mg/L. The NOEC for inhibition of growth rate was determined to be 2.7 mg/L. The test item thus showed a significant toxic effect on the green unicellular algae Raphidocelis subcapitata.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

4.9 mg/L

Additional information

The effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata was determined according to OECD 201 and Regulation (EC) No. 266/2016 Method C.3 under GLP. The study was conducted under static conditions with an initial cell density of 1E4 cells/mL for a period of 72 hours. Nominal concentrations of 9.5, 17.1, 30.9, 55.6 and 100.0 % v/v saturated solution corresponding to calculated geometric mean concentrations were the followings: 1.4, 2.7, 4.9, 9.3 and 17.2 mg/L and control was performed. The obtained results showed that the test item had significant toxic effects on the growth of Raphidocelis subcapitata. All validity criteria were met. The results are based on measured geometric mean test item concentrations. The EC50-values for inhibition of growth rate (ErC50) and for inhibition of yield (EyC50) were determined to be >17.2 and 6.8 mg/L, respectively. The ErC10 and EyC10 values were determined to be 4.9 and 2.1 mg/L, respectively. The NOEC for inhibition of growth rate and for inhibition of yield were determined to be 2.7 and 1.4 mg/L, resepctively. The test item showed a significant toxic effect on the green unicellular algae.

Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.