Sulphoethyl methacrylate

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:

June 2019

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:

yes

Details on sampling:

Duplicate samples from the freshly prepared test media (containing algae) of all test concentrations and from the control were taken at the start of the test.
For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the control (containing algae) were taken after 24 hours and at the end of the test (after the 72 hours test period) by pooling aliquots of the contents of the test beakers of each treatment.
All samples were diluted by a factor of two with acetonitrile.
Additional samples of the control and of the dilution solvent were taken at each sampling without any sample treatment.

Vehicle:

no

Details on test solutions:

A defined amount of the test item was added directly to the test water for each test concentration and was carefully stirred for 24 hours in the dark to dissolve as much of the test item as possible. The highest test item concentration of 100 mg test item/L was prepared by mixing 101.5 mg test item into 1015 mL test water, for the test item concentration of 32 mg test item/L, 32.1 mg test item were mixed into 1003 mL test water, for the concentration of 10.0 mg test item/L, 10.1 mg were mixed into 1010 mL test water. The concentration of 3.20 mg test item/L was prepared by mixing 6.5 mg into 2031 mL test water and for 1.0 mg test item/L, 5.0 mg were mixed into 5000 mL test water. After cessation of mixing and a following period (1 hour) of settling to allow phase separation, the aqueous phase, i.e. the water accommodated fraction, was drawn off carefully and used as the test medium of the corresponding nominal test concentration. The test media were prepared just before introduction of the algae (= start of the test).
Test Concentrations:
Due to the low limit of water solubility of the test item Water accommodated Fractions (WAF) with nominal loading rates of 100, 32, 10, 3.2, 1.0 mg test item/L and a control were tested corresponding to following geometric mean measured concentrations of the test item: 21.9, 9.84, 5.51, 1.25 and 0.319 mg test item/L and a control.
Control: In the control, test water was used without addition of the test item.

Test organisms (species):

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

Details on test organisms:

Species: Pseudokirchneriella subcapitata, Strain No. 61.81 SAG
Origin: The algae were supplied by the "Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen", 37073 Göttingen, Germany.
Breeding Conditions: The algae were cultivated in the laboratories of IBACON under standardised conditions according to the test guidelines.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

Calculated water hardness of the test water: 0.24 mmol/L (= 24 mg/L) as CaCO3

Test temperature:

22 to 23°C

Details on test conditions:

Water Temperature: The temperature was measured daily in an Erlenmeyer flask filled with water and incubated under the same conditions as the test flasks.
Water temperature was: 22.1 to 23.0 °C
pH-Values: The pH was measured in all test item concentrations and the control at the start and the end of the test.
pH was: 7.8 to 8.0 at test start and 7.9 to 9.1 at test end
Light Regime: Continuous illumination
Light Intensity: The light intensity was measured once during the test at 6 positions distributed over the experimental area at the surface of the test media.
Mean light intensity: 6203 lux (range: 5940 to 6470 lux)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 215 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

> 215 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 215 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

215 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

99.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

139 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 215 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Validity criteria fulfilled:

yes

Conclusions:

The EC50 for 2-SEM against algae is >215 mg/l. Therefore 2-SEM is not classified as hazardous to aquatic environment.

Description of key information

The EC50 for 2-SEM against algae is >215 mg/l. Therefore 2-SEM is not classified as hazardous to aquatic environment.

Key value for chemical safety assessment

EC50 for freshwater algae:

215 mg/L