Tyrosine

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

Study period:

From 2018-01-17 to 2018-02-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tyrosine

EC Number:

200-460-4

EC Name:

Tyrosine

Cas Number:

60-18-4

Molecular formula:

C9H11NO3

IUPAC Name:

tyrosine

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L, and control.
- Sampling method: taken from the limit test concentration and control at test start and after 24 hours from fresh and aged solutions and after 48 hours from aged solutions. For each sampling also a retain sample was taken.
- Sample storage conditions before analysis: stored deep frozen

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock solution S1: weighed necessary amount of test item to a volumetric flask, added test medium up to the bench mark and then homogenised by shaking and 45 min of ultrasonication.
- Evidence of undissolved material: the solution was clear and transparent

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Daphnia magna (Straus), clone V
- Source: originally purchased from the Federal Environment Agency in Berlin/Germany
- Age at Test Start: Less than 24 hours
- Breeding Conditions: feed with single cell green algae (Desmodesmus subspicatus) at least three times a week.
- Feeding during test: no

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

232 mg CaCO3/L

Test temperature:

18.9 to 21.9 °C

pH:

7.58 – 7.79

Dissolved oxygen:

7.8 - 9.2 mg/L

Nominal and measured concentrations:

Nominal: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass vessel (100 mL)
- Type: closed
- Fill volume: filled up with ~ 50 mL test solution
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: ~ 10 mL of test solution for each animal

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium
- pH: 7.68
- Dissolved oxygen concentration: 9.2 mg/L
- Total hardness:13°dH (232 mg/L as CaCO3)
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod /8 hours darkness daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Biological Assessment: after 24 h and 48 h: count the immobilised daphnids and record behavioural changes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

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

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Biological Assessment: After 24 and 48 hours of exposure no immobilisation was observed in the control and at 100 mg/L test item. No behavioural changes could be observed.
- Analytical Results: The initial measured content of test item was between 94 and 95 % of nominal and the aged measured content was 91 % of nominal.

Results with reference substance (positive control):

EC50 (24 h) < 1.00 mg/L, in accordance with the requirements of the OECD guideline 202 and fall within the historical data, the daphnids were suitable for the determination of the toxicological effects of the test item.

Reported statistics and error estimates:

Due to an inhibition below 50% the database was weak for probit analysis which hence was not performed

Any other information on results incl. tables

Results of the test, 48 h values:

	Nominal test item concentration [mg/L]
	Control	100
	Immobilised daphnids after 48 h
Group 1	0	0
Group 2	0	0
Group 3	0	0
Group 4	0	0
Total	0	0
%	0	0

EC₅₀and NOEC-values of daphnids exposed to the test item evaluated using nominal concentrations:

Endpoint	Test item [mg/L]
	24 h	48 h
NOEC	100	100
EC50	>100	>100
95% confidence limit of EC50	-	-

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the results of the test, the EC50 (48 h) for immobilisation was determined to be > 100 mg/L (nominal). The corresponding NOEC (48 h) was 100 mg/L (nominal).

Executive summary:

The immobilisation effect of the test item on the water flea Daphnia magna was determined under worst-case exposure conditions according to OECD 202 (2004).

Semi - static limit test (100 mg/L) with twenty organisms per test concentration (4 replicates of 5 animals each) were used. The duration of the test was 48 hours.

Analytical samples taken at 0 hours (initial value) and 24 hours from fresh and at 48 hours from aged test solutions were analysed from control and the limit test concentration.

The initial measured content of test item was between 94 and 95 % of nominal and the aged measured content was 91 % of nominal. The toxicological endpoints were evaluated using nominal concentrations.

According to the results of the test, the EC50 (48 h) was determined to be > 100 mg/L (nominal). The corresponding NOEC (48 h) was 100 mg/L (nominal).