5-potassium hydrogen L-glutamate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13th April 2004

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

1

Reference substance name:

5-potassium hydrogen L-glutamate

EC Number:

243-094-0

EC Name:

5-potassium hydrogen L-glutamate

Cas Number:

19473-49-5

Molecular formula:

C5H9NO4.K

IUPAC Name:

potassium 5-oxido-5-oxo-L-norvaline

Test material form:

solid

Specific details on test material used for the study:

TEST ITEM
Information supplied by the Sponsor:
Name: L-Glutamic acid potassium salt monohydrate1
Lot number*: VG29748063
CAS number: 6382-01-0
Description: White powder
Expiry date: 01 December 2022
Purity: 100 %
Storage conditions: Room temperature (15-25 ºC, below 70% relative humidity)
Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask)
for unknown materials will be applied to assure personnel health and
safety.
The certificate of analysis is presented in Appendix 3.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The analytical phase of the study was conducted at the Test Facility. For determination of the test item
concentration, samples were taken from the test solutions and the controls at the start and at the end of
the experiment. Samples were shipped immediately after collection for concentration measurement to
the Test Facility.
The concentration analyses were conducted under the control of the Analyst, based on the analytical
method validation and in compliance with the relevant SOPs of the Test Facility. The results are
included in the Study Report as Appendix 2.

Test solutions

Vehicle:

no

Details on test solutions:

The stock solution (100 mg/L) was prepared by adding the test material directly to the aerated tap
water. The test solutions were prepared just before the start of the experiment.
A stock solution of 100 mg/L was first prepared by dissolving the test item in tap water. The test
solutions were prepared by appropriate dilution (10, 100, 1000 and 10000 fold) of this stock solution.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Species and strain: Daphnia magna laboratory strain
Sex: Female
Source: 100 female D. magna were issued from the National Institute of
Pharmacy and were cultured and maintained further in the Test Site’s
laboratory.
Justification of species: Daphnia magna is the standard species of the acute immobilisation
test.
Number of animals: There were 30 animals at each group (concentration and untreated
control) divided into 6 replicates
(5 animals/1 parallel)
Age of animals: Less than 24 hours old at the beginning of the test. The first breeding
of the previous generation was not used.
Acclimatization: To avoid the necessity of adaptation prior to the test, the
environmental conditions used in the experiment were similar to the
culture conditions (water temperature, pH and light period).
Holding water: Same water was used as test water (see 3.2.3.).
Food and Feeding: The Daphnia group was fed with concentrated algal suspension of
Raphidocelis subcapitata. Test animals were not fed during the
exposure.
Breeding conditions: Daphnids were cultured in 5 L beakers in an incubator operated for
this purpose, with a dark-light cycle (16 hours light) and temperature
control (22 ± 1 °C). The system was located in the Test Site.
During the maintenance of the stock, the phenological appearance of
the animals were constantly monitored and only healthy animals were
kept in the culture.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

22+-1 C

pH:

The pH was measured in the control(s) and in the test solutions at the start and at the end of the experiment. The pH did not vary by more than 1.5 units in any test.

Dissolved oxygen:

The oxygen concentration was ≥ 3 mg/L of the air saturation value at the temperature used

Nominal and measured concentrations:

measured

Details on test conditions:

As the test material was stabil in this test medium, the test was conducted in a static system layout.
The vessels were held for the duration of the study in a climate chamber under controlled conditions,
The test temperature was 22 ± 1 °C. The water temperature was determined daily in one control test
vessel and continuously with a min/max thermometer in the climate chamber.
The oxygen concentration and pH were measured in the control(s) and in the test solutions at the start
and at the end of the experiment. The oxygen concentration was ≥ 3 mg/L of the air saturation value at
the temperature used. The pH did not vary by more than 1.5 units in any test.
The light-dark cycle during the test was 16 hours light (artificial illumination) and 8 hours darkness.

Reference substance (positive control):

yes

Remarks:

For the evaluation of the quality of the Daphnia clones and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilised daphnids, or any other adverse effects (including abnormal behaviour) were
observable during the test at the control and maximum concentration at any exposure time.

Results with reference substance (positive control):

For the evaluation of the quality of the Daphnia clones and the experimental conditions, Potassium
dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

Any other information on results incl. tables

Concentration of the test item was analytically determined at the start and at the end of the test.
No immobilised daphnids, or any other adverse effects (including abnormal behaviour) were
observable during the test at the control and maximum concentration at any exposure time.
Results are presented in Table 3.
Table 3.: Number and percentage of immobilised daphnids

Test item concentration (mg/L)	Number of treated animals	Immobilised animals
24 hours	48 hours
Number	Percent (%)	Number	Percent (%)
100	30	0	0	0	0
Control	30	0	0	0	0

The pH and dissolved oxygen content remained stable during the test in the validity range.
Results are presented in Table 4.
Table 4.: pH and dissolved oxygen concentration content

Dose Group	pH start	DO start (mg/L)	pH end	DO end (mg/L)
Control	8.11	9.1	8.35	8.92
Control	8.30	8.94
Control	8.25	8.96
Control	8.19	9.06
Control	8.24	9.12
Control	8.22	9.05
100	8.27	9.3	8.35	9.40
100	8.38	9.22
100	8.30	9.17
100	8.29	9.33
100	8.28	9.37
100	8.33	9.42

DO: Dissolved oxygen
Overall, the test item showed no adverse effect in the test system.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this 48-hour acute toxicity test with Daphnia magna, the 48 h EC50 and EC100 values were
determined to be higher than 100 mg/L, and the 48 h NOEC was determined as 100 mg/L.

Executive summary:

The aim of the study was to evaluate the acute toxicity of the test material using the Daphnia sp., acute
immobilisation test, conducted on Daphnia magna, under GLP circumstances.
The study was conducted in accordance with OECD Guideline for testing of chemicals on Daphnia
sp., Acute Immobilisation Test (adopted by the council on 13th April 2004).
As no mortality was observed during the non-GLP preliminary study, a limit test was performed. The
test animals were exposed to aqueous test media containing the test item for 48 hours at only one
technical concentration (100 mg/L) plus a control in order to demonstrate that the test item has no
influence on the mobility of Daphnia up to this test concentration. Considering the information about
the stability of the test item, a static test was performed.
Significant toxic effect was not observed during the preliminary range-finding test, therefore only one
test concentration and one control group was tested in a limit test. Samples were taken and analysed
from the test concentration and the control at the start and at the end of the experiment. The
quantification of the test item was performed in the analytical laboratory of the test facility.
There was no immobilisation in the daphnids exposed to either test item treated or control group. In
addition to immobility, no abnormal behaviour or appearance of test animals was detected.
Accordingly, the 48-h NOEC was determined as 100 mg/L. The 48-h EC50 and EC100 values were
determined to be higher than 100 mg/L. All biological results are related to the measured test item
concentration.
Conclusion: In this 48-hour acute toxicity test with Daphnia magna, the 48 h EC50 and EC100
values were determined to be higher than 100 mg/L, and the 48 h NOEC was
determined as 100 mg/L.