1-(3-tert-butyl-1,3,3-trimethyl-1-alkenyldisiloxanyl)-4-alkylheterocycle

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Analytical samples taken at 0 hours (initial value) and 24 hours from fresh and 48 hours aged test solutions were analysed from control, solvent control and all test item concentrations

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus, Clone V, max. 24 hours old.

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

48 h

Test conditions

Hardness:

The total hardness (as CaCO3) of the untreated control was determined to be 13°dH (232 mg/L CaCO3).

Test temperature:

The mean temperature of the control and all test item concentrations was measured to be 19.8 ± 0.6 °C (Std. Dev.)

pH:

The mean pH-value of the untreated control was determined to be 7.98 ± 0.11 (Std. Dev.).

Dissolved oxygen:

The mean oxygen concentration was determined to be 8.9 ± 0.1 mg/L (Std. Dev.).

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

27.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

20.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 5

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

2.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 6

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

2.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 7

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.17 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 8

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Applicant's summary and conclusion

Conclusions:

According to the results of the test, the EC50 (48 h) was determined to be 20.4 mg/L (nominal) and 2.40 mg/L (actual). The corresponding NOEC (48 h) was 12.5 mg/L (nominal) and 2.25 mg/L (actual).

Executive summary:

Biological Results

After 24 hours of exposure no immobilisation was observed in the control, solvent control and up to and including 12.5 mg/L. 50 % of the daphnids were immobile in the test item concentration of 25.0

mg/L. 90 % immobilisation was observed at the highest test item concentration of 50.0 mg/L.

In the test item concentrations of 25.0 and 50.0 mg/L fine oil droplets were observed at the surface of the test item solution. The daphnids did pend at the surface and were partly sticky.

After 48 hours of exposure no immobilisation was observed in the control, solvent control and all test item concentrations up to and including 6.25 mg/L. No immobilisation higher than the allowed

control immobilisation was observed 12.5 mg/L. 75 % immobilisation was observed at 25.0 mg/L. In the highest test item concentration of 50.0 mg/L all daphnids were immobile.

In the test item concentrations of 3.13 and 6.25 mg/L the daphnids did partly pend to the surface of the test item solutions. In the test item concentrations of 12.5 mg/L and above, all daphnids did

pend at the surface of the test item solutions. Additionally the same observations were made in the test item concentrations of 25.0 and 50.0 mg/L as after 24 hours.

Analytical Results

The initial measured content of VSV16 was between 11 and 143 % of nominal and the aged measured content was between 3 and 25 % of nominal. Therefore the toxicological endpoints were

evaluated using nominal and actual (based on the geometric mean of each concentration level) concentrations.