2-hydroxy-3-(prop-2-enoyloxy)propyl 2-methyl-2-propylhexanoate

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 October 17, 2016 to October 21, 2016

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:

yes

Remarks:

but uncritical, assessed and signed by the study director

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

but uncritical, assessed and signed by the study director

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch no.: JBGJ0045R
Purity: 100% (UVCB)
Appearance: clear yellowish liquid

Analytical monitoring:

yes

Remarks:

HPLC-UV

Details on sampling:

At the beginning and at the end of the test, the content of the test substance in the test solutions was determined using HPLC-UV -determination. The control and treatments at 2.2, 4.6 and 10 mg/L were measured undiluted. The treatments at 22 and 46 mg/L were diluted with drinking water (1:1 and 1:9) before measurement. Filtration using 0.45 µm PTFE filters was not possible. Because of the limited solubility of the test substance, the correlation between nominal and measured concentration was weak. In the 2 highest test concentrations the measured concentrations were in a similar range. Therefore, the determination of the biological results was based on the geometric mean of the measured concentrations

Vehicle:

no

Details on test solutions:

Deionised water with an enrichment of certain minerals (dilution water as demanded in the guidelines) was used in the test. The water-accommodated fractions (WAF) were prepared. This was done by pipetting 46, 22, 10, 4.6 and 2.2 mL/L corresponding to the nominal loads 46, 22, 10, 4.6 and 2.2 mg/L (based on a density of 1.01 g/mL) on the surface of dilution water and stirring slowly for 23 hours. The lower phase was used as test solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

- Species: Daphnia magna; Variety: STRAUS; Strain: Berlin; Origin: Umweltbundesamt Berlin; Sex: female; Age: between 0 and 24 hours
- Vessels: preserving glasses, nominal volume 2 L; Medium M4-Medium (recipe of ELENDT); Food: unicellular green algae (Desmodesmus subspicatus); Medium renewal: twice a week; Photo period: 16/8 hours, using neon tubes; Temperature 20 ± 2°C.
- 21 hours before the start of the test, the adult animals were separated from the young. 0.5 hours before test start, the adults were caught with the help of a glass tube, and the newborn Daphnia, aged between 0 and 23 hours, were sieved from the medium and immediately placed into a 250 mL-beaker containing dilution water. After a settling-in period of 30 minutes, animals which showed no apparent damage were used for the test. (Switching from M4-medium (husbandry) to dilution water (test) has been shown not to cause any detri-mental effects for test Daphnia.)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg CaCO3/L

Test temperature:

18.1 – 20.5°C

pH:

7.7 - 7.9

Dissolved oxygen:

7.8 - 8.8 (O2-Concentration in mg/L)

Salinity:

-

Conductivity:

-

Nominal and measured concentrations:

0, 2.2, 4.6, 10, 22 and 46 mg/L nominal concentrations (corresponding to 0, 2.67, 4.04, 5.11, 23.68 and 21.81 measured concentrations)
(The concentrations to be tested are based on the result of a non GLP pre-test with nominal concentration of 1, 10 and 100mg/L. At the nominal loading of 100 mg/L, 100% immobilisation was observed. At the loading of 10 mg/L and 1 mg/L none of the daphnia was immobilised.)

Details on test conditions:

- Treatments: 4 vessels, each containing 20 mL test solution and 5 Daphnia
- Blank control: 4 vessels, each containing 20 mL dilution water and 5 Daphnia

One valid experiment was performed.
The study was performed using 5 concentrations ranging from 2.2 to 46 mg/L nominal concentration. For each test concentration, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.
The 2 highest concentrations caused 100% immobilisation. The lower concentrated treatments showed no significant toxicity. None of the animals were immobilised in the blank control.
Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study. The 24h-EC50 value was determined as 1.7 mg/L, lying within the demanded range of 0.6 – 1.7 mg/L stated in the guideline.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: corresponding to 8.3 mg/L measured

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

19 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: corresponding to 17 mg/L measured

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: corresponding to 5.11 mg/L measured

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: corresponding to 21.91 mg/L measured

Details on results:

In the 2 highest test concentrations, the measured concentrations were in a similar range and in both treatments 100% immobilisation was observed. The measured concentration in treatment 46 mg/L was slightly lower than in treatment 22 mg/L. Therefore treatment 22 mg/L was not used for evaluation. (Additionally the results were calculated based on the nominal concentrations 0, 2.2, 4.6, 10 and 22 mg/L)

Results with reference substance (positive control):

The 24h-EC50 value was determined as 1.7 mg/L, lying within the demanded range of 0.6 – 1.7 mg/L stated in the guideline.

Reported statistics and error estimates:

NOEC and LOEC were determined by comparing of the respective treatment with the blank control. Statistically insignificant variation is considered as “no observed effect”, although the EC values which were read from the graph toxicity vs. concentration may lie lower. The estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.2.1.

Table 1. Nominal and measured concentrations for treatment and blank control

Conditions	Nominal concentrations (mg/L)	Measured concentrations (mg/L)
Blank (control)	0.0	not determined
Treatment	2.2	2.67
Treatment	4.6	4.04
Treatment	10	5.11
Treatment	22	23.68
Treatment	46	21.81

Because of the limited solubility of the test substance, the correlation between nominal and measured concentration was week. In the 2 highest test concentrations the measured concentrations were in the same range. Therefore, the determination of the biological results was based on the geometric mean of the measured concentration. Geometric mean is calculated by multiplication of the n participating concentrations and taking the n^throot.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 24 and 48h EC50 (Daphnia magna) of the test substance were determined to be 19 and 13 mg/L nominal (corresponding to 17 and 8.3 mg/L measured). The LOEC and NOEC were established at 22 and 10 mg/L nominal (corresponding to 21.81 and 5.11 mg/L measured).

Executive summary:

A study was conducted to determine the short-term toxicity of the test substance to aquatic invertebrates according to OECD Guideline 202 and EU Method C.2. Daphnia magna were exposed to water accomodated fractions (WAFs) prepared at loading rates of 0 (control), 2.2, 4.6, 10, 22 and 46 mg/L under static conditions for 48 h. Mobility of the Daphnia was evaluated at 0 and 48 h and samples for analytical dose verification were taken from all groups at test start and end. Analysis of the samples showed measured concentrations of 0.0, 2.67, 4.04, 5.11, 23.68 and 21.81 in the WAFS at 0.0, 2.2, 4.6, 10, 22 and 46 mg/L, respectively. The 2 highest concentrations caused 100% immobilisation. The lower concentrated treatments showed no significant toxicity. None of the animals were immobilised in the blank control. Under the study conditions, the 24 and 48 h EC50 (Daphnia magna) of the test substance were determined to be 19 and 13 mg/L nominal (corresponding to 17 and 8.3 mg/L measured). The LOEC and NOEC were established at 22 and 10 mg/L nominal (corresponding to 21.81 and 5.11 mg/L measured) (Muckle, 2016).

Description of key information

The 48h EC50 value for Daphnia magna due to the test substance was determined to be 8.3 mg/L (measured).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8.3 mg/L

Additional information

A study was conducted to determine the short-term toxicity of the test substance to aquatic invertebrates according to OECD Guideline 202 and EU Method C.2. Daphnia magna were exposed for 48h to WAFs prepared at loading rates of 0 (control), 2.2, 4.6, 10, 22 and 46 mg/L under static conditions. Mobility of the Daphnia was evaluated at 0 and 48 h and samples for analytical dose verification were taken from all groups at test start and end. Analysis of the samples showed measured concentrations of 0.0, 2.67, 4.04, 5.11, 23.68 and 21.81 in the WAFS at 0.0, 2.2, 4.6, 10, 22 and 46 mg/L, respectively. The 2 highest concentrations caused 100% immobilisation. The lower concentrated treatments showed no significant toxicity. None of the animals were immobilised in the blank control. Under the study conditions, the 24 and 48h EC50 (Daphnia magna) of the test substance were determined to be 19 and 13 mg/L nominal (corresponding to 17 and 8.3 mg/L measured). The LOEC and NOEC were established at 22 and 10 mg/L nominal (corresponding to 21.81 and 5.11 mg/L measured) (Muckle, 2016).