complex mixture from biological origin

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

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:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

31.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

31.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

14.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

14.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

47.2 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

47.2 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

ca. 234 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: CI (185 - 274)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

ca. 20.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: CI (< 10.0 – 38.2)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

ca. 110 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

ca. 9.72 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

ca. 444 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: CI (382 - 567)

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

ca. 55.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: CI (34.9 – 84.4)

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

ca. 210 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

ca. 26.3 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

983 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: CI: (918 > 1000)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

258 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: CI (206 - 335)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 464 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 122 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Details on results:

For details please see section "any other information on results incl. tables".

Results with reference substance (positive control):

The toxicity of potassium dichromate (SIGMA, batch number MKBV0900V, purity 99.0 %, CAS RN 7778-50-9) to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined over a period of 72 hours from 2017-04-18 to 2017-04-21. The reference item toxicity is in the valid range following test facility SOPS. For results, please see table 9 in section "any other details on results incl. tables".

Reported statistics and error estimates:

For information on statistics, please see section "any other details on materials and methods incl. tables".

Validity criteria fulfilled:

yes

Conclusions:

In this study, the test item was found to inhibit the growth of the freshwater green alga Pseudokirchneriella subcapitata after 72 hours with the following effect values (based on nominal test item concentrations): The EC50-values with 95% confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 983 (918 - > 1000) mg test item/L and 258 (206 - 335) mg test item/L. The EC10-values with 95% confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 234 (185 - 274) mg test item /L and 20.6 (< 10.0 – 38.2) mg test item /L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 31.6 mg test item/L. Based on solid content concentrations, the following effect values were obtained: The EC50-values with 95% confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 464 (433 - > 472) mg solid content/L and 122 (97.2 - 158) mg solid content/L. The EC10-values with 95% confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 110 (87.3 - 129) mg/L and 9.72 (< 4.72 – 18.0) mg solid content/L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 14.9 mg solid content/L.

Executive summary:

The toxicity of Sophorolipids, partially hydrolysed, to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined according to the principles of OECD 201 and Council Regulation (EC) No. 266/2016 Method C. The aim of the study was the determination of NOEC, LOEC, EC10- , EC20- and EC50-values of the growth rate and the yield over a period of 72 hours.

The study was conducted under static conditions with an initial cell density of 6839 cells/mL. A stock solution and four dilution levels out of the stock solution were tested in a geometrical series with a dilution factor of √10: 10.0 - 31.6 - 100 - 316 - 1000 mg/L, corresponding to 4.72 – 14.9 – 47.2 – 149 – 472 mg solid content/L. Three replicates were tested for each test item concentration and six replicates for the control. The environmental conditions were within the acceptable limits.

The test media were visually clear at the start and after 24 hours of the exposure. After 48 and 72 hours of the exposure the test media were concentration related turbid. Although care was taken to avoid the formation of foam during preparation a concentration related foam formation was observed in the test media throughout the test period.

The concentrations of the solid content of the test item were analytically verified via LC-MS/MS at the start (0 h) and at the end (72 h) of the exposure in all tested concentration levels and the control. The measured concentrations at the start of the exposure were in the range of 94 and 102 % of the nominal values. At the end of the exposure the measured concentrations of the test item were in the range of 84 to 105 %. The measured concentrations were all within ± 20% of the nominal concentrations. This indicates that the test item concentrations were successfully maintained for the duration of the test.

The EC50-values with 95 % confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 983 (918 - > 1000) mg test item/L and 258 (206 - 335) mg test item/L. The EC10-values with 95% confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 234 (185 - 274) mg test item /L and 20.6 (< 10.0 - 38.2) mg test item /L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 31.6 mg test item/L.

Based on solid content concentrations, the following effect values were obtained: The EC50-values with 95 % confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 464 (433 - > 472) mg solid content/L and 122 (97.2 - 158) mg solid content/L. The EC10-values with 95 % confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 110 (87.3 - 129) mg/L and 9.72 (< 4.72 - 18.0) mg solid content/L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 14.9 mg solid content/L.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

 

 

Description of key information

The EC50-values with 95 % confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 464 (433 - > 472) mg solid content/L and 122 (97.2 - 158) mg solid content/L. T The NOEC-values for both inhibition of growth rate and yield after 72 hours were 14.9 mg solid content/L.

This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Key value for chemical safety assessment

EC50 for freshwater algae:

464 mg/L

EC10 or NOEC for freshwater algae:

14.9 mg/L

Additional information

The toxicity of Sophorolipids, partially hydrolysed, to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined according to the principles of OECD 201 and Council Regulation (EC) No. 266/2016 Method C. The aim of the study was the determination of NOEC, LOEC, EC10- , EC20- and EC50-values of the growth rate and the yield over a period of 72 hours.

The study was conducted under static conditions with an initial cell density of 6839 cells/mL. A stock solution and four dilution levels out of the stock solution were tested in a geometrical series with a dilution factor of √10: 10.0 - 31.6 - 100 - 316 - 1000 mg/L, corresponding to 4.72 – 14.9 – 47.2 – 149 – 472 mg solid content/L. Three replicates were tested for each test item concentration and six replicates for the control. The environmental conditions were within the acceptable limits.

The test media were visually clear at the start and after 24 hours of the exposure. After 48 and 72 hours of the exposure the test media were concentration related turbid. Although care was taken to avoid the formation of foam during preparation a concentration related foam formation was observed in the test media throughout the test period.

The concentrations of the solid content of the test item were analytically verified via LC-MS/MS at the start (0 h) and at the end (72 h) of the exposure in all tested concentration levels and the control. The measured concentrations at the start of the exposure were in the range of 94 and 102 % of the nominal values. At the end of the exposure the measured concentrations of the test item were in the range of 84 to 105 %. The measured concentrations were all within ± 20 % of the nominal concentrations. This indicates that the test item concentrations were successfully maintained for the duration of the test.

The EC50-values with 95 % confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 983 (918 - > 1000) mg test item/L and 258 (206 - 335) mg test item/L. The EC10-values with 95% confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 234 (185 - 274) mg test item /L and 20.6 (< 10.0 - 38.2) mg test item /L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 31.6 mg test item/L.

Based on solid content concentrations, the following effect values were obtained: The EC50-values with 95 % confidence intervals for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 464 (433 - > 472) mg solid content/L and 122 (97.2 - 158) mg solid content/L. The EC10-values with 95 % confidence intervals for inhibition of growth rate (ErC10) and yield (EyC10) after 72 hours were 110 (87.3 - 129) mg/L and 9.72 (< 4.72 - 18.0) mg solid content/L. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 14.9 mg solid content/L.

Based on reliable data determined with the target substance, the following parameters were used for assessment:

EC50 for freshwater algae: 464 mg/L based on active ingredient

NOEC for freshwater algae: 14.9 mg/L based on active ingredient

This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the attached read-across report (see IUCLID section 13).