Sodium olivoyl glutamate

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:

2023

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)

Version / remarks:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Series on Testing and Assessment No. 23 - Guidance Document On Aquatic Toxicity Testing Of Difficult Substances And Mixtures ENV/JM/MONO(2000)6/REV1 (2019).

Version / remarks:

2019

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SODIUM OLIVOYL GLUTAMATE
Common name: Sodium olivoyl glutamate
Chemical name: Glutamic acid, N-olivoyl derivs., sodium salts
CAS number: 1628321-85-6
EC number: 944-266-4

SOURCE OF TEST MATERIAL
Supplier: Sponsor
Batch number: 2072900-M
Expiry date: 29/07/2023
Purity: nominal content 100.0%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
Storage condition: at room temperature, light protection not needed.

Analytical monitoring:

yes

Details on sampling:

The concentration of SODIUM OLIVOYL GLUTAMATE in the test medium was analytically measured according to a fully validated analytical method (study CH - 0926-2022). Samples of test solution were taken after preparation at time 0 (“fresh” solutions), from renewed solutions at time 24 hours (”spent” and “fresh” solutions) and at the end of the test period, 48 hours (“spent” solutions). Negative and solvent control samples were analysed at the same time to verify the absence of test item contamination. Samples were labelled and analysed after sampling.

Vehicle:

no

Details on test solutions:

Prior to the test start, a 100.0 mg test item/L stock solution (SS1) was prepared by direct weighting 0.0501 g of test item into 501 mL of reconstituted water. The stock solution was clear and transparent with slightly foam on the flask’s meniscus. After 24 hours of exposure, test item solution was freshly prepared following the same procedure in order to test medium renew (0.0500 g into 500 mL). A negative control (with reconstituted water only) was also tested.

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed on the freshwater crustacean Daphnia magna Straus. A strain of this species was supplied by MicroBioTests Inc., Belgium in July 2017 (batch number: DM060417). Since that time, the clone has been bred in the laboratories of the Test Facility under conditions identical to those of the test, with regard to temperature, light and water quality, so that no acclimation was needed prior to testing. It was daily fed with a fixed amount of the laboratory cultured green algae Raphidocelis subcapitata (also known as Pseudokirchneriella subcapitata) and with a suspension of the yeast Saccharomyces cerevisiae. At the test start the organisms used in the test were less than 24 hours old and were not first brood progeny. No feeding occurred during testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Water Hardness: 10 - 250 mg/L as CaCO3

Test temperature:

The test was performed in a controlled environment room. The incubation temperature was continuously monitored during the study by a probe installed in the environmental test chamber. It was in the range 19.93 - 20.17°C with a mean value of 20.00°C and a standard deviation of 0.03°C. In agreement with the temperature range provided by OECD guideline 202, 2004 (20 ± 2°C), the temperature values during the test were within the provided range and did not vary more than 1°C during the test period.

pH:

The pH was determined in the control and in test item solution at the start, after 24 hours and at the end of the test. At the test start, in fresh test media, pH was measured sampling an aliquot immediately after test solution preparation, before pouring it in the test beakers. After 24 and 48 hours, pH was measured after removing the daphnids from the test beakers containing spent solutions.
The pH measured during the test period are reported below. The pH in the negative control beakers did not vary by more than 0.72 unit during the test period, as required in the OECD guideline.

pH negative control test item (100 mg/L)
0 h 7.49 7.42
24 h spent 8.08 7.93
24 h fresh 8.21 7.80
48 h 7.78 7.79

Dissolved oxygen:

Prior to the study start, the test water was aerated until oxygen saturation was reached. During the test period, the test water was not aerated.
The dissolved oxygen concentration was determined in the control and in test item solution at the start, after 24 hours and at the end of the test. At the test start, in fresh test media, the dissolved oxygen concentration was measured sampling an aliquot immediately after test solution preparation, before pouring it in the test beakers. After 24 and 48 hours, the dissolved oxygen concentration was measured after removing the daphnids from the test beakers containing spent solutions.
The dissolved oxygen concentration in the negative control and in the test item solution was always higher than 6.0 mg/L, according to OECD Guideline 202 that provides a minimum oxygen concentration of 3.0 mg/L.

Dissolved oxygen (mg/L) negative control test item (100 mg/L)
0 h 8.37 8.60
24 h spent 8.49 7.98
24 h fresh 8.98 9.00
48 h 7.79 7.46

Salinity:

The test was performed on reconstituted water. For reconstituted test water preparation, analytical grade salts were dissolved in purified water until obtaining the following nominal concentrations:

CaCl2 x 2H2O 2.0 mmol/L (= 294.0 mg/L)
MgSO4 x 7H2O 0.5 mmol/L (= 123.3 mg/L)
NaHCO3 0.771 mmol/L (= 64.8 mg/L)
KCl 0.078 mmol/L (= 5.8 mg/L)
Alkalinity 0.8 mmol/L
Ratio of Ca : Mg = 4 : 1 (based on molarity)
Ratio of Na : K = 10 : 1 (based on molarity)

Conductivity:

Conductivity was not determined, since test medium was prepared starting from purified water (no surface nor ground water).

Nominal and measured concentrations:

Analytical recovery of SODIUM OLIVOYL GLUTAMATE measured concentrations

Time (hours) 0:
Nominal test item concentrations (mg/L): 100
Actual SODIUM OLIVOYL GLUTAMATE concentration (mg/L): 90.70
Analytical recovery (%): 90.7

Time (hours) 24 spent
Nominal test item concentrations (mg/L): 100
Actual SODIUM OLIVOYL GLUTAMATE concentration (mg/L): 31.87
Analytical recovery (%): 31.9

Time (hours) 24 fresh
Nominal test item concentrations (mg/L): 100
Actual SODIUM OLIVOYL GLUTAMATE concentration (mg/L): 94.61
Analytical recovery (%): 94.6

Time (hours) 48 spent
Nominal test item concentrations (mg/L): 100
Actual SODIUM OLIVOYL GLUTAMATE concentration (mg/L): 24.64
Analytical recovery (%): 24.6

Time-weighted arithmetic mean of SODIUM OLIVOYL GLUTAMATE measured concentrations
Test item concentration (mg/L): 100.0
Measured concentration T0 (mg/L): 90.70
Measured concentration T24 spent (mg/L): 31.87
Measured concentration T24 h fresh (mg/L): 94.61
Measured concentration T48 h (mg/L): 24.64
Time-weighted mean (mg/L): 54.13

Details on test conditions:

TEST SYSTEM
The test was performed in glass beakers filled with 40 mL of test medium. After aeration before prior to the study start, during the test the test vessels were covered with glass plates to reduce the loss of water and to avoid dust entry into test solutions.
Tested concentrations were (i) negative control (reconstituted water without test item) and (ii) 100.0 mg test item/L. The study was conducted in a semi-static exposure regimen, with a renewal at 24 hours.
For the test concentration and for the negative control, group of 20 daphnids were used divided into four replicates of five daphnids each. The daphnids were randomly distributed to the test vessels at test initiation and transferred into fresh test item solutions after 24 hours of exposure. The daphnids loading rate was more than 2 mL per one daphnid (according to OECD Guideline 202, 2004).

TEST MEDIUM APPEARANCE
The test medium appearance was visually recorded at the start of the test, after 24 hours and at the end of the test. No remarkable observations were made concerning the appearance of the test media. The test solutions did not change throughout the whole test duration.

OTHER TEST CONDITIONS
The daily photoperiod was 16 hours light and 8 hours darkness. The measured values were in the range 1091-1179 Lux.

RANGE-FINDING STUDY
The test concentration, 100.0 mg test item/L, was chosen based on the results of a preliminary acute toxicity screening (non GLP preliminary test), in which no immobilization was observed at 0, 1, 10 and 100 mg/L (test item nominal concentration) at both 24 and 48 hours.

Reference substance (positive control):

yes

Remarks:

The reference substance was potassium dichromate 1N.

Key result

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

24 h

Dose descriptor:

other: EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

24 h

Dose descriptor:

other: EC20

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

ca. 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

48 h

Dose descriptor:

other: EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

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

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

Biological results (immobilisation) assessed based on nominal test item concentration.

Key result

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

48 h

Dose descriptor:

other: EC20

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 54.13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

Biological results (Immobilization) assessed based on time-weighted arithmetic mean of active ingredient measured concentrations)

Details on results:

The test solutions did not change throughout the whole test duration. No immobilization was observed in both negative control and test item groups. Sub-lethal effects (daphnids behaviour and appearance) were assessed after 24 hours of exposure and at the end of the test. No remarkable observations were made concerning the appearance of daphnids in the negative and in the test item medium.
Analytical recoveries of SODIUM OLIVOYL GLUTAMATE during the test period are reported in the section "Nominal and measured concentrations". Since all analytical recoveries were not in the range 80% - 120% of the nominal concentrations, the biological results were referred to the time-weighted arithmetic mean of SODIUM OLIVOYL GLUTAMATE measured concentrations, as recommended by OECD Guidance Document on testing of difficult substances No. 23, 2019.

Results with reference substance (positive control):

The reference substance potassium dichromate 1N showed an EC50 at 24 hours of 1.8 mg/L (CI 95% 1.6-2.1) in the internal laboratory test performed on the same clone of Daphnia a few months before the current study. This result is in full agreement with published data and demonstrates that the used Daphnia clone has an adequate level of sensitivity to that substance.

Time-weighted arithmetic mean of SODIUM OLIVOYL GLUTAMATE measured concentrations

Test item concentration (mg/L)	Measured concentration T0 (mg/L)	Measured concentration T24 spent (mg/L)	Measured concentration T24 h fresh (mg/L)	Measured concentration T48 h (mg/L)	Time-weighted mean (mg/L)
100.0	90.70	31.87	94.61	24.64	54.13

 

  Immobilization effect of test item to Daphnia magna

Nominal test item concentration (mg/L)	No. of Daphnia tested	No. of immobilized Daphnia		% of immobilized Daphnia
		24 h	48 h	24 h	48 h
0.0 (negative control)	20	0	0	0	0
100.0	20	0	0	0	0

 

Validity criteria fulfilled:

yes

Remarks:

In the negative control, 0% immobilization was observed and no daphnid was trapped on the test water surface or showed other signs of disease or stress. The oxygen concentrations at the end of the test were > 3 mg/L in both control and test vessels.

Conclusions:

No adverse effect was observed after 48 hours of exposure at the nominal concentration of 100.0 mg test item/L. This value corresponds to 54.13 mg test item/L as time-weighted arithmetic mean.

Executive summary:

The acute toxicity of test item SODIUM OLIVOYL GLUTAMATE was tested on Daphnia magna under semi-static conditions in a limit dose test. No adverse effect was observed after 48 hours of exposure at the nominal concentration of 100.0 mg test item/L. Therefore, EC10, EC20 and EC50 were > 100 mg/L, and NOEC was equal or greater than 100 mg/L (as nominal concentrations). 
Since the test item concentration decreased during the exposure, the time-weighted arithmetic mean was calculated and was found equal to 54.13 mg test item/L. As reported in the OECD Guideline No. 202 (2004), and No 23 (2019) since analytical recoveries of active ingredient were not within 80% - 120% of nominal values during the test period, the end-points were calculated based on time-weighted arithmetic mean of SODIUM OLIVOYL GLUTAMATE measured concentrations. EC10, EC20 and EC50 were > 54.13 mg/L, and NOEC was equal or greater than 54.13 mg/L (measured concentrations). 

Description of key information

No adverse effect was observed after 48 hours of exposure at the nominal concentration of 100.0 mg test item/L. This value corresponds to 54.13 mg test item/L as time-weighted arithmetic mean.