Glutamic acid

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

other: SIDS

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference 1

Reference Type:

publication

Title:

SIDS for L-Glutamic acid

Author:

OECD

Year:

2013

Report date:

2013

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Specific details on test material used for the study:

1. Name : L-glutamic acid
2. Supplier : Sigma-Aldrich Inc.
3. Purity : >=99.5%
4. Lot No. : 1371820
5. Storage condition : Stored at room temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

At initial exposure (0 hour) and at the end of exposure (after 48 hours), the samples from each one dish of the control and treatment groups were collected twice, and then each sample was analyzed.

Test solutions

Details on test solutions:

1. Culturing and dilution: M4 medium
2. Preparation of test solutions: For preparation of stock solutions, an appropriate amount of the test substance was measured using an electronic balance and then added to mass flask filled with the dilution water (range finding test, definitive test) and then were dissolved. For the preparation of the test solutions, an appropriate amount of stock solutions was added to mass flasks filled with the dilution water (range finding test, definitive test), and then they were mixed. Each 100 mL of test solutions was prepared for test concentrations of 100, 10, 1, and 0.1 mg/L in the range finding test and for test concentration of 100 mg/L in the definitive test. The dilution water was using as the control group. The test solution was prepared on the day.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

1. Source: The 7 days old daphnids were provided from National Institute of Agricultural Science & Tech. Twenty five daphnids were kept in a glass beaker with 800 mL of dilution water.
2. Test Organism: Young daphnids, which are bone from not less than 14 days old daphnids that were above third brood progeny and less than 24 hours old, were used for this study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

250 mg/L as CaCO3

Test temperature:

20.0-20.6 °C

pH:

7.24-7.87

Dissolved oxygen:

6.88-7.41 mg/L

Nominal and measured concentrations:

- Nominal concentrations (mg/L) : control, 100
- Mean measured concentrations (mg/L) : control, 83.14

Details on test conditions:

1. Experimental design: Twenty daphnids
2. Feeding and aeration : Without feeding and aeration during 48 hours of exposure period
3. Photoperiod : 16 hours of continuous artificial light and 8 hours of continuous darkness with 30 minutes dawn and dusk transition period between light and darkness

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 83.14 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 83.14 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Details on results:

1. Cumulative number of organisms immobilised and general symptoms (Table 1, 2): During the exposure period, no immobilisation and abnormal sings were found in the control group and the treatment group at 83.14 mg/L measured concentration.
2. Observation of test solutions:The test solutions in the control group and the treatment group at 83.14 mg/L measured concentration were observed for clearness prior to exposure initiation and during the exposure period.

Results with reference substance (positive control):

The positive control study using Daphnia magna to exposure in Potassium Dichromate (Wako Pure Chemical Industries, Ltd., Japan) as a reference material for 48 hours was performed once every six months, and then EC50 was determined. The results of this study were confirmed within the range permitted for the test (mean±2SD) by historical control data in this laboratory of Biotoxtech Co., Ltd. Exposure conditions for the positive control study were in the same conditions as the definitive test.

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 at 24 and 48 hours that was obtained under the test conditions with the test substance, L-glutamic acid was determined >83.14 mg/L, respectively. And, the No Observed Effect Concentration (NOEC) was determined ≥83.14 mg/L.

Executive summary:

This study was designed to assess the acute toxicity of the test substance, L-glutamic acid, on the immobilisation of Daphnia magna during the exposure period of 48 hours under static test conditions and to determine the EC50 (median effect concentration) for the immobilisation of Daphnia magna and the No Observed Effect Concentration (NOEC). The nominal concentration was set at 100 mg/L, and the control group was prepared for this study. The concentration at the end of exposure exceeded (+/-) 20% of the measured initial values. Therefore, all test results were determined the geometric means. During the exposure period, the percentage of immobilisation in the control group was below 10%, and no abnormal signs such as trapping at surface of water were found. As a result of the definitive test, the percentage of immobilisation was less than 50% in the highest concentration treatment group during the exposure period, so the EC50 at 24 and 48 hours was determined >83.14 mg/L, respectively. And, the No Observed Effect Concentration (NOEC) was determined 83.14 mg/L.