Reaction mass of 3,7-dimethyloct-7-en-1-yl 3-methylbut-2-enoate and 3,7-dimethyloctyl 3-methyl-2-butenoate and citronellyl 3-methylcrotonate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From June 19,2017 to September 22,2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch Number: VE00463145
Appearance: Colorless to pale yellow liquid
Expiration Date: April 06,2018
Purity: 99.9 % (sum of isomers)

Analytical monitoring:

yes

Details on sampling:

For the determination of the actual test item concentrations, duplicate samples were taken from each test concentration and the control at the start and at the end of the two 24-hour test medium renewal periods.
For sampling from the aged test media, the contents of the respective replicates were combined prior to sampling.
Immediately after sampling, acetonitrile (1 mL acetonitrile per mL sample volume) was added to each sample to stabilize the latter during the storage period. Thereafter, all samples were frozen (at -20 ± 5 °C). Based on analytical pre-experiments for investigation of the storage stability, the test item was found to be stable in the test water under these storage conditions.
The concentrations of SINODOR CQ were analyzed in one of the duplicate test medium samples taken from all treatments and all sampling dates.

Vehicle:

no

Details on test solutions:

At the start of the test and at the start of the renewal period after 24 hours, the highest test medium (i.e: the undiluted equilibrated test medium with a loading rate of 100 mg/l) was prepared following the slow-stirring method.
The equilibrated aqueous phase with a loading rate of 100 mg/L, containing dissolved test item only, was used as highest test concentration and was diluted with the test water to obtain the test media with the lower test concentrations, i.e. the dilutions 1:2.2, 1:4.6, 1:10 and 1:22.
Additionally, a control (test water only) was run in parallel.

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with young daphnids of the species Daphnia magna Straus.
At the start of the test, the organisms used in the test were 6-24 hours old and were not first brood progeny.

Test type:

semi-static

Water media type:

other:

Remarks:

Reconstitued test water (ISO Test Water)

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/L as CaCO3

Test temperature:

The water test temperature was in the range of 21-22°C during the test

pH:

The pH values of the test media were between 7.9 and 8.2

Dissolved oxygen:

The dissolved oxygen concentrations in the test media and control were at least 8.1 mg/L

Nominal and measured concentrations:

The results demonstrate the correct preparation of the test media, i.e. the spacing factor of 2.2 between the different test concentrations was met. At the end of the test medium renewal periods, 43 to 67 % of the initially measured values were found demonstrating a decrease of test item concentrations during the 24-hour renewal periods.

Nominal and Mean Measured Test Concentrations :

Dilution of Saturated Solution Mean Measured Exposure Concn. (mg/L)
1 : 22 0.0062 mg/L
1 : 10 0.016 mg/L
1 : 4.6 0.029 mg/L
1 : 2.2 0.061 mg/L
Undiluted 0.15 mg/L

Details on test conditions:

Based on the results of the stirring experiment and the range-finding test and in agreement with the Sponsor, the following concentrations of SINODOR CQ were selected for the main test: the equilibrated test medium with a loading rate of 100 mg/L and the dilutions 1:2.2, 1:4.6, 1:10 and 1:22.
Additionally, a control (test water without test item) was tested in parallel.
The main test was performed in a closed system to avoid losses of the test item by evaporation.
Based on the analytical results of the pre-experiments, a semi-static main test with test medium renewal after 24 hours was chosen to keep the concentration as constant as possible during the test period of 48 hours. After 24 hours, the test organisms were transferred by wide-bore pipette in to clean test vessels with freshly prepared test medium of the corresponding concentration.

Reference substance (positive control):

yes

Remarks:

Potassium Dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.076 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

95% Confidence

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.029 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.15 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The biological results are based on the mean measured test item concentrations.
A clear dose-response effect was obeserved during the exposure period of 48 hours:
At the 3 lower test concentartions of 0.0062 to 0.029 mg/L, no toxic effects were observed until test end.
At the next higher concentration of 0.061 mg/L, 25% of the daphnids were found to be immobile following 48 hours of exposure.
At the highest concentration of 0.015 mg/L, all daphnids were found to be immobile after 48hours.

Results with reference substance (positive control):

The result of the latest positive control test in March 2017 (24-hour EC50: 1.2 mg/L, IES Laboratories Study 20170076) showed that
the sensitivity of the test organisms was within the range given by the guideline (24-hour EC50:0.60-2.1 mg/L).

Validity criteria fulfilled:

yes

Conclusions:

During the first 24 hours of the test, no immobilized test organisms were determined in the control and up to and including the mean measured concentration of 0.061 mg/L. At the highest concentration of 0.15 mg/l, 100 % of the daphnids were found to be immobile.
The 24-hour EC50 of the test item was calculated to be 0.10 mg/L with 95% confidence limits of 0.061 and 0.15 mg/L.
The 24hour EC0 and NOEC were at the concentration of 0.061 mg/L.
The 24 hour EC100 was 0.15 mg/L.


After 48 hours of exposure, no immobolized test organisms were determined in the control and up to and including the test concentration of 0.029 mg/L.
At the next higher concentration of 0.061 mg/L, 25% of the daphnids were found to be immobile.
All other daphnids were mobile, but showed reduced swimming activity at this concentration.
At the highest concentration of 0.15 mg/L, 100% of the daphnids were found to be immobile.
The 48 hours EC50 was calculated to be 0.076 mg/L with 95% confidence limits of 0.060 and 0.095 mg/L.
The 48 hour EC0 and NOEC of SINODOR CQ were both at the mean mesured concentration of 0.029 mg/L, since no toxic effect was obeserved up to and including this test concentration.
The 48 hours EC 100 was at the mean measured concentration of 0.15 mg/L.

Executive summary:

The acute toxicity of the test item SINODOR CQ to Daphnia magna was determined in a

48-hour test according to the OECD Guideline for Testing of Chemicals, No. 202 (2004) and

the Commission Regulation (EC) No. 440/2008, Part C.2.

As the test item is a volatile substance, the test was performed using glass tubes completely

filled (without headspace) with test medium that were tightly sealed with glass stoppers to avoid

losses of test item by evaporation (closed system). A semi-static test design with a test medium

renewal after 24 hours was used.

As the test item is a liquid with low water solubility, the slow-stirring method (to avoid

formation of micro emulsions) was applied for preparation of a saturated test item solution. For

this, the test item with density of 0.8957 g/cm3 (at 20 °C) was carefully applied (pipetted) on

the surface of the test water at a loading rate of 100 mg/L. Thereafter slow-stirring was applied

for 48 hours in a closed vessel to reach a maximum concentration of dissolved test item in the

test water. The stirring vessel was nearly completely filled (a small headspace had to be

included as the test item was floating on the water surface) and tightly sealed with glass stoppers

to avoid losses of the volatile test item during stirring.

After this treatment the lower part of the equilibrated test medium was carefully harvested from

the stirring vessel through a tap at the bottom of the vessel. This equilibrated aqueous phase

with a loading rate of 100 mg/L, containing dissolved test item only, was used as highest test

concentration and was diluted with test water to obtain the dilutions 1:2.2, 1:4.6, 1:10 and 1:22.

Additionally, a control (test water without test item) was tested in parallel.

The preparation of the test media was based on the OECD Guidance Document No. 23 on

Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000.

The measured concentrations of the test item SINODOR CQ in the test media of all test

concentrations at the start and end of the test medium renewal periods are shown in the table

below. The results demonstrate the correct preparation of the test media, i.e. the spacing factor

of 2.2 between the different test concentrations was met. At the end of the test medium renewal

periods, 43 to 67 % of the initially measured values were found demonstrating a decrease of

test item concentrations during the 24-hour renewal periods.

Description of key information

During the first 24 hours of the test, no immobilized test organisms were determined in the control and up to and including the mean measured concentration of 0.061 mg/L. At the highest concentration of 0.15 mg/l, 100 % of the daphnids were found to be immobile.

The 24-hour EC50 of the test item was calculated to be 0.10 mg/L with 95% confidence limits of 0.061 and 0.15 mg/L.

The 24hour EC0 and NOEC were at the concentration of 0.061 mg/L.

The 24 hour EC100 was 0.15 mg/L.

After 48 hours of exposure, no immobolized test organisms were determined in the control and up to and including the test concentration of 0.029 mg/L.

At the next higher concentration of 0.061 mg/L, 25% of the daphnids were found to be immobile.

All other daphnids were mobile, but showed reduced swimming activity at this concentration.

At the highest concentration of 0.15 mg/L, 100% of the daphnids were found to be immobile.

The 48 hours EC50 was calculated to be 0.076 mg/L with 95% confidence limits of 0.060 and 0.095 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.076 mg/L

Additional information

48 hour EC50 = 0.076 mg/L

48 hour EC0 = 0.029 mg/L

48 hour EC100 = 0.15 mg/L