Phosphoric acid, 2-ethylhexyl ester, sodium salt

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2019-05-13 to 2019-07-05

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)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

LC/MS/MS

Details on sampling:

For determination of the test item concentrations in the test solution and in the control samples, all four test vessel were analysed at the start and at the end of the test. Samples were taken from the test item treated group and from the control group (4 x 3 mL at the start and 4 x 3 mL at the end of the study).

Vehicle:

no

Details on test solutions:

The test solution was prepared by mechanical dispersion without using any solubilizing agent. An amount of 0.0308 g test item was dissolved in 308 mL dilution water in order to obtain the nominal concentration of 100 mg/L. The test solution was freshly prepared just before introduction of test animals (start of the experiment).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna (Straus)
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age of animals at test start: less than 24 h
- Feeding during test: no
- Method of breeding: Test animals were bred under similar (or the same) conditions as that used during the exposure period (holding water, temperature, background colour etc.), therefore, additional acclimatisation before the test was not necessary.

ACCLIMATION
- Acclimation period: Brood daphnids were maintained in dilution water at the test temperature for at least 48 hours prior to the start of the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

249 mg/L (as CaCO3)

Test temperature:

20.0 - 21.4 °C

pH:

7.60 - 7.98

Dissolved oxygen:

8.48 - 9.16 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentration: 91 mg/L at the start and 97 mg/L at the end of the test

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Material, size, headspace, fill volume: glass, 50 mL volume
- Volume of solution: 40 mL
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO Medium, prepared according to OECD 202
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 h light : 8 h dark
- Light intensity: 821 lux

RANGE-FINDING STUDY
- Test concentrations: control and 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilised animals were observed during the exposure period, therefore, a limit test with 100 mg/L test concentration was performed as the main test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilisation or any abnormal behaviour of the test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the test concentration of 100 mg/L after 48 hours of exposure.

Results with reference substance (positive control):

For the evaluation of the quality of the Daphnia clone and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions. The date of the last study with reference item Potassium dichromate was: 12 - 13 March 2019.
The 24-h EC50: 1.58 mg/L (95 % conf. limits: 1.34 – 1.85 mg/L)

Preliminary Range-Finding Test

After the exposure period no immobilised daphnids were observed neither in the control, nor in the test solution. Therefore, a limit test was performed as the main test.

Analyticals Results

The mean of the measured concentrations of the test item in the test solution was 91 % of the nominal value at the start and 97 % of the nominal value at the end of the test. There is evidence that the concentration of the tested substance was maintained within ± 20 % of the nominal concentration throughout the test. Therefore, the analysis of the results was based on the nominal concentration value. Test item was not detected in the control group.

Validity criteria fulfilled:

yes

Conclusions:

In this 48-hour acute toxicity test on Daphnia magna, the obtained results showed that the test item had no toxic effects on the mobility of Daphnia up to the concentration of 100 mg/L. The 48-h EC50 was determined to be higher than 100 mg/L and the 48-h NOEC was determined to be 100 mg/L.

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202, Regulation (EC) No. 440/2008 Method C.2 and EPA OPPTS 850.1010. The study was conducted in a static system over a period of 48 hours with a limit concentration of 100 mg/L. 20 daphnids per test concentration and control were tested. The test item concentration was determined at the start and at the end of the test with LC/MS/MS and it was in the range of 91 - 97 % of the nominal concentration. Therefore, the biological endpoints were based on the nominal concentration. The validity criteria of the test guideline were fulfilled. There was no immobilisation observed in the twenty daphnids exposed to the test item treated and control groups. Further no abnormal behaviour or appearance of test animals was noted. The estimated EC50 value (48 hours) of the test item based on the nominal concentration is >100 mg/L. The NOEC was determined to be 100 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June - September 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1981, adapted 1983

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1984

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: not specified
- Source: not specified
- Age of animals at test start: less than 24 h
- Feeding during test: not specified

ACCLIMATION
- Acclimation period: not specified

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

20 ± 2 °C

pH:

8.2

Dissolved oxygen:

5.3 - 7.8 mg/L

Nominal and measured concentrations:

Nominal concentration: 10, 100 and 1000 mg/L
No measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers
- Material, size: glass, 50 mL, fill volume: 20 mL
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: according to the EEC Directive (84/449, Part C.2)
The water used was bi-distilled water. The pH of the reconstituted water was adjusted to 7.9 ± 0.3.

EFFECT PARAMETERS MEASURED
- visual control of the mobility of the daphnids after 24 h.
- oxygen concentration and pH at beginning and end of experiment.

Reference substance (positive control):

not specified

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 - < 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

<= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Conclusions:

The 24-h acute toxicity test to Daphnia magna revealed a nominal EC0 value of > 100 mg/L and an EC100 value of ≤ 1000 mg/L after 24 hours. The EC50 value was determined to be > 100 mg/L.

Executive summary:

The 24 -h acute toxicity of the test item to Daphnia magna was studied under static conditions according to OECD 202 (1983) and EU method C.2 (1984). Daphnids were exposed to the test item at nominal concentrations of 10, 100 and 1000 mg/L. No analytical monitoring was performed. During the study the dissolved oxygen, pH, water temperature and the immobilization rate were measured. Based on the number of immobile daphnids the EC values were determined. The EC0 value was > 100 mg/L (nominal) and the EC100 was ≤ 1000 mg/L after 24 hours. The EC50 value was determined to be > 100 mg/L.

Description of key information

In a 48-hour acute toxicity test on Daphnia magna, the obtained results showed that the test item had no toxic effects on the mobility of Daphnia up to the concentration of 100 mg/L. The 48-h EC50 was determined to be higher than 100 mg/L and the 48-h NOEC was determined to be 100 mg/L. A 24-h immobilisation study with Daphnia magna supports the obtained results in the 48-h test. The 24-h EC50 was determined to be >100 mg/L.

Additional information

Key:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202, Regulation (EC) No. 440/2008 Method C.2 and EPA OPPTS 850.1010. The study was conducted in a static system over a period of 48 hours with a limit concentration of 100 mg/L. 20 daphnids per test concentration and control were tested. The test item concentration was determined at the start and at the end of the test with LC/MS/MS and it was in the range of 91 - 97 % of the nominal concentration. Therefore, the biological endpoints were based on the nominal concentration. The validity criteria of the test guideline were fulfilled. There was no immobilisation observed in the twenty daphnids exposed to the test item treated and control groups. Further no abnormal behaviour or appearance of test animals was noted. The estimated EC50 value (48 hours) of the test item based on the nominal concentration is >100 mg/L. The NOEC was determined to be 100 mg/L.

Supporting:

The 24-h acute toxicity of the test item to Daphnia magna was studied under static conditions according to OECD 202 (1983) and EU method C.2 (1984). Daphnids were exposed to the test item at nominal concentrations of 10, 100 and 1000 mg/L. No analytical monitoring was performed. During the study the dissolved oxygen, pH, water temperature and the immobilization rate were measured. Based on the number of immobile daphnids the EC values were determined. The EC0 value was > 100 mg/L (nominal) and the EC100 was ≤ 1000 mg/L after 24 hours. The EC50 value was determined to be > 100 mg/L.