4-aminobutyric acid

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)

Rationale for reliability incl. deficiencies:

other: Well documented study according to international accepted guideline and GLP compliant.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

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

Test material information

Constituent 1

Reference substance name:

4-aminobutyric acid

EC Number:

200-258-6

EC Name:

4-aminobutyric acid

Cas Number:

56-12-2

Molecular formula:

C4H9NO2

IUPAC Name:

4-aminobutanoic acid

Test material form:

solid: crystalline

Details on test material:

Test item: 4-Aminobutyric acid
CAS number: 56-12-2
Batch number BCBN4740V
Physical state: Solid, crystalline powder
Colour: White
Storage: at 15-30 °C

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION OF STOCK SOLUTION
The preparation of stock and test solutions was based on the preliminary non GLP range finding test. As the Range Finding Test was not performed in compliance with the GLP-Regulations it is excluded from the Statement of Compliance in the final report, but the raw data of this test are archived under the study code of present study.
For the stock solution 300.3 mg of test item was measured into 1 500 ml Elendt M4 medium. The emulsion were stirred and ultrasonicated till complete dilution of the test item. The stock solution was clear and colourless. The nominal concentration of stock solutions was 200 mg/L.

PREPARATION OF TEST SOLUTIONS
Seven dilution levels were prepared by mixing appropriate volume of Elendt M4 medium and stock solution of the test item. The maximum separation factor between of test vessels was 2.0. The volume of the prepared test solutions was 300 ml.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna Straus
Age: < 24 hours neonates
Origin: National Institute of Environmental Health
Culture conditions: The test species is maintained in Elendt M4 medium with culture conditions at 21±1 °C and a light/dark cycle of 16/8 hours with light intensities of less than 1000 Lux. The cultures are fed with centrifugalized green alga (Pseudokirchneriella subcapitata) cells daily at weekdays.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

The temperature of thermostat was recorded daily and registered continuously by Extech datalogger.
The temperature inside the thermostat at the test vessels was measured and registered continuously.

pH:

The pH was measured at the beginning and at the end of the test. At the beginning of the test the pH was measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the pH was measured in each test vessel.

Dissolved oxygen:

The dissolved oxygen was measured at the beginning and at the end of the test. At the beginning of the test the dissolved oxygen was measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the dissolved oxygen was measured in each test vessel.

Nominal and measured concentrations:

The nominal concentration of the stock solutions was 200 mg/L. In the test the following nominal concentrations of test solutions were applied:
200; 160; 120; 100; 80; 60 and 40 mg/L.

Details on test conditions:

The test was maintained under static conditions for a period of 48 hours.
At the start of the study each test vessels contained 50 ml of test solutions and five young daphnids. In the test four replicates total of 20 animals at each test
concentration level were investigated. The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C with a 16/8 hours light/dark cycle.
Each control vessels containing five young daphnids in Elendt M4 medium were prepared in four replicates and kept under the same static conditions.
The number of immobilised and abnormally behaved daphnids was recorded after 24 and 48h. A daphnia is considered to be immobile if it is not able to swim within 15 seconds after a gentle agitation of the test vessel. The daphnids were not fed during the test.

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 200 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

According to the test results the test item has not got any toxic effect on Daphnia magna sp., up to 200 mg/L concentration. The no-observed-effect-concentration of the test item is at or above 200 mg/L, NOEC: ≥ 200.00 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to this Daphnia sp., Acute Immobilisation Test for 4-Aminobutyric acid the results indicated that the test item is not hazardous to the aquatic environment [48 hr EC50 (for Crustacea) > 100 mg/L].