ethyl 2-acetyl-4-methyltridec-2-enoate

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

Lot No. : 43
Purity : 96.5%
Expiration date : September 05, 2017

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.
All samples were stored frozen (at -20 ± 5 °C) immediately after sampling. 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 (see Analytical Procedure, Appendix 1).
The concentrations of GR-86-6599 were analyzed in one of the duplicate test medium samples
taken from all sampling dates.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with young daphnids of the species Daphnia magna Straus. A clone
of this species (originally from the Daphnia Collection of the University of Basel/Switzerland
in 2015) is successfully bred in IES Ltd Laboratories. The cultivation of the parental daphnids
is performed in reconstituted water of the quality identical to the water quality used in the tests
(with respect to pH, main ions, and total hardness) and under temperature and light conditions
identical to those of the tests.
During breeding, daphnids were generally fed three times a week with an algal suspension of
the green algae Desmodesmus subspicatus, supplied by the Collection of Algal Cultures (SAG,
Institute for Plant Physiology, University of Göttingen, 37073 Göttingen/Germany) and
cultivated at IES Ltd Laboratories under standardized conditions or a mixture of this algal
suspension and a commercial fish diet (Tetra Min® Hauptfutter, supplied by TETRA-Werke,
49324 Melle/Germany).

Test type:

semi-static

Water media type:

other: Reconstituted test water according to ISO 6341

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/L

Test temperature:

21°C

pH:

7.7 - 7.9

Dissolved oxygen:

8.4 mg/L

Nominal and measured concentrations:

The results obtained for the concentrations of the test samples are presented in Table 7. The
concentrations determined in the freshly prepared test sample (day 0/0 hours) were 34.8 μg/L
(dilution 1:5.1), 43.8 μg/L (dilution 1:3.4), 72.5 μg/L (dilution 1:2.3), 99.9 μg/L (dilution 1:1.5)
and 135 μg/L (undiluted).
The concentrations determined in the test samples taken from the fresh test media
(day 1/0 hours) were 32.9 μg/L (dilution 1:5.1), 46.9 μg/L (dilution 1:3.4), 73.4 μg/L (dilution
1:2.3), 104 μg/L (dilution 1:1.5) and 151 μg/L (undiluted).
The concentrations determined in the test samples taken from the aged test media
(day 1 / 24 hours) were found to be 26.2 μg/L (dilution 1:5.1), 42.9 μg/L (dilution 1:3.4),
58.4 μg/L (dilution 1:2.3), 72.8 μg/L (dilution 1:1.5) and 99.2 μg/L (undiluted).
The concentrations determined in the test samples taken from the aged test media (day 2 /
24 hours) were found to be 25.8 μg/L (dilution 1:5.1), 48.4 μg/L (dilution 1:3.4), 58.7 μg/L
(dilution 1:2.3), 68.1 μg/L (dilution 1:1.5) and 114 μg/L (undiluted).
The results showed the correct preparation of the test samples. For most of the samples, the test
item concentration slightly decreased over the test period.

Reference substance (positive control):

yes

Remarks:

Potassium Dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 123 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

This exposure concentration represents the maximum water saturation concentration of the test item

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 123 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

This exposure concentration represents the maximum water saturation concentration of the test item

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 123 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

This exposure concentration represents the maximum water saturation concentration of the test item

Details on results:

The test is considered to be valid, as in the control no daphnids showed immobilization or other
signs of disease or stress (e.g., discolouration or unusual behaviour such as trapping at the
surface of water). Furthermore, the dissolved oxygen concentration at the end of the test was
≥3 mg/L in all test vessels.

After 48 hours of exposure, no immobilized test organisms were determined in the control and up to and including the highest test concentration of 123 µg/L, corresponding to the saturation concentration of the test item.

As no toxic effect was observed, the 48-hour EC50, 48-hour EC100 and the NOEC were determined directly from the raw datadate to be >123 µg/L and the EC0 and NOEC to be ≥ 123 µg/L.

Results with reference substance (positive control):

Potassium Dichromate : EC50 (24 hour) = 1.0 mg/L

Validity criteria fulfilled:

yes

Conclusions:

In conclusion the test item GR-86-6599 had no acute toxic effects on Daphnia magna in a
48-hour semi-static test up to the highest test concentration of 123 μg/L, corresponding to the
saturation concentration of the test item.

Executive summary:

The acute toxicity of the test item GR-86-6599 to Daphnia magna was determined in a 48-hour

semi-static 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 was applied for

preparation of a saturated test item solution. For preparation of the highest concentrated test

medium, the test item was carefully applied (pipetted) onto the surface of the test water at a

loading rate of 50 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 mixing 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. After this treatment, stirring was

stopped for 24 hours as a precaution to allow phase separation in case test item droplets had

been mixed into the water column during stirring. Following cessation of mixing and the period

of settling, the lower aqueous and equilibrated phase was carefully separated from the nondissolved

upper test item phase through the tap at the bottom of the vessel. This equilibrated

aqueous phase with a loading rate of 50 mg/L, containing dissolved test item only, was used as

highest test concentration and considered to represent the aqueous saturation concentration in

test media of the test item. The highest test concentration was subsequently diluted with test

water to obtain the following test media: the dilutions 1:5.1, 1:3.4, 1:2.3 and 1:1.5. 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 GR-86-6599 in the test media of all test

concentrations at the start and end of the two 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 1.5 between the different test concentrations was sufficiently met. At the end of the

test medium renewal periods, 65 to 103% of the initially measured values were found.

From these results the mean measured concentrations were calculated as follows: for each test

medium renewal period (i.e. Day 0 to Day 1, Day 1 to Day 2), the mean concentration was

calculated as the geometric mean of the test item concentrations measured at the start and the

end of the test medium renewal period. From the two geometric mean values obtained, the mean

measured test item concentration during the test period of 48 hours was calculated as an

arithmetic mean.

The biological results are based on the mean measured concentrations.

After 48 hours of exposure, no immobilized test organisms were determined in the control and

up to and including the highest test concentration of 123 μg/L, corresponding to the saturation

concentration of the test item.

As no toxic effect was observed, the 48-hour EC50 and 48-hour EC100 were determined directly

from the raw data to be >123 μg/L and the EC0 and NOEC to be ≥123 μg/L.

In conclusion the test item GR-86-6599 had no acute toxic effects on Daphnia magna in a

48-hour semi-static test up to the highest test concentration of 123 μg/L, corresponding to the

saturation concentration of the test item.

Description of key information

The acute toxicity of the test item GR-86-6599 to Daphnia magna was determined in a 48-hour semi-static 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 no toxic effect was observed, the 48-hour EC50 and 48-hour EC100 were determined directly from the raw data to be >123 μg/L and the EC0 and NOEC to be ≥123 μg/L.

In conclusion the test item GR-86-6599 had no acute toxic effects on Daphnia magna in a 48-hour semi-static test up to the highest test concentration of 123 μg/L, corresponding to the saturation concentration of the test item.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.123 mg/L