Disodium L-tyrosinate

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:

25.07.2017 to 27.07.2017

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

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

Details on sampling:

For determination of the test item concentrations, four replicate samples (5 mL per replicate) were taken from the test solution (100 mg/L) and from the control at the start and at the end of the test.

Vehicle:

no

Details on test solutions:

The test solutions used in the test was prepared by mechanical dispersion without using any solubilising agents. An amount of 0.03 g test item was dissolved in 300 mL dilution water (ISO Medium) to obtain the nominal concentration of 100 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: 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 parental stock (mean and range, SD): Less than 24 hours old
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

approximate 249 mg/L

Test temperature:

20.2 – 20.5°C (test vessels), 20.1 – 21.0°C (climate chamber)

pH:

7.75 – 9.72 (Control: 7.79 - 7.95)

Dissolved oxygen:

7.91 – 8.24 mg/L

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

Nominal: 100 mg/L
The measured concentration of L-Tyrosine disodium salt hydrate was 104% of the nominal at the start and 96% at the end of the test. The measured test item concentration remained within ± 20% of the nominal during the test period of 48 hours, therefore, the biological results are based on the nominal concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Medium volume per beaker: at least 40 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Photoperiod: 16 h light and 8 h darkness
- Light intensity: 649 lux

RANGE-FINDING STUDY
- Test concentrations: 100 mg/L (plus control)
- Results used to determine the conditions for the definitive study: No immobility or any sub-lethal effects were detected in the test concentration and in the control group during the 48-h exposure period.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, experimantal phase: 07 – 08 March 2017

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: measured value for hydrat

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: measured value for hydrat

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: measured value for hydrat

Details on results:

There was no immobilisation observed in twenty daphnids exposed to either test item treated or control group. In addition to immobility, no abnormal behaviour or appearance of test animals was detected.

Results with reference substance (positive control):

24h EC50: 1.41 mg/L (95 % confidence limits: 1.19 – 1.68 mg/L)

Reported statistics and error estimates:

For determination of the ECx values Probit analysis was performed using SPSS software. Other endpoints were determined directly from the raw data.

Validity criteria fulfilled:

yes

Conclusions:

In this 48-hour static acute toxicity test with Daphnia magna the effects of the test item on the mobility was determined. The 48-h EC50 value was determined to be > 100 mg/L (hydrated substance) and > 85.1 mg/L (calculated for anhydrous substance). The 48-h NOEC was determined to be 100 mg/L (hydrated substance) and 85.1 mg/L (calculated for anhydrous substance).

Executive summary:

The purpose of this study was to evaluate the influence of the test item on the mobility, respectively survival of Daphnia magna in a static test system. Young Daphnia were exposed in an immobilisation test to aqueous test media containing the test item at 100 mg/L. Twenty Daphnia, divided into four groups of five animals each were exposed to the test item concentrations or run as control for 48 hours. The 48-h EC50 value was determined to be > 100 mg/L (hydrated substance) and > 85.1 mg/L (calculated for anhydrous substance). The 48-h NOEC was determined to be 100 mg/L (hydrated substance) and 85.1 mg/L (calculated for anhydrous substance).

Description of key information

The 48-h EC50 value of the test item on Daphnia magna was determined to be > 100 mg/L (hydrated substance) and > 85.1 mg/L (calculated for anhydrous substance).

Additional information

In the acute immobilisation test (reference 6.1.3-1) with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD Guideline for testing of chemicals, Guideline No. 202, adopted 13th April 2004. The study was conducted in a static system over a period of 48 hours with a nominal concentration of 100 mg/L. The validity criteria of the test guideline were fulfilled. The EC50 value (48 hours) was determined to be > 100 mg/L (hydrated substance) and 85.1 mg/L (calculated for anhydrous substance).