Histidine

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:

2015-10-16 to 2016-05-24

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)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Principles of method if other than guideline:

Study was performed as limit test at concentration 100 mg/L.

GLP compliance:

yes (incl. QA statement)

Details on test solutions:

- Concentration: 100 mg/L
- Treatments: 4 vessels containing 20 mL and 5 Daphnia
- Blank control: 4 vessels containing 20 mL dilution water and 5 Daphnia

Test organisms (species):

Daphnia magna

Details on test organisms:

- Variety: Straus
- Strain: Berlin
- Sex: female
- Age: young Daphnia, less than 24h at start test
- Origin: Umweltbundesamt Berlin
- In-house breeding since 2007-09-27
- Breeding conditions
2L-vessels containing M4-Medium (recipe of ELENDT)
Food: unicellular green algae (Desmodesmus subspicatus)
Medium renewal, twice a week
Photoperiod: 16/8 hours, neon tubes
Temperature: 20 +/- 2 °C
- Acclimation: no
- Selection of Daphnia:
19 hours before the start of the test, the adult animals were separated from the young. 0.5 hours before test start, the adults were caught with the help of a glass tube, and the newborn Daphnia, aged between 0 and 23 hours, were sieved from the medium and im- mediately placed into a 250 mL-beaker containing dilution water. After a settling-in period of 30 minutes, animals which showed no apparent damage were used for the test.
Switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test Daphnia.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

Immobilized Daphnia are counted. Daphnia are considered to be immobilised if they perform no movements or are only able to move their antennae when the beaker is gently agitated. Daphnia which are trapped at the surface of the test solution are also considered immobilised.

Hardness:

2.502 mmol/L

Test temperature:

20 +/- 2°C

pH:

initial pH 7.7

Dissolved oxygen:

8.6 mg O2/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentrations: 102 % and 105 % of nominal concentration at beginning and end of test respectively.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

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

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The treatment showed no toxicity. None of the animals were immobilised in the control nor in the test solutions.

Results with reference substance (positive control):

The 24h EC50 value is 1.6 mg/L, which is within the demanded range 0.6 - 1.7 mg/L

Validity criteria fulfilled:

yes

Conclusions:

L-Histidine is not toxic to Daphnia Magna at a concentration of 100 mg/L. The 48h-EC50 value is > 100 mg/L and 48h-NOEC ≥ 100 mg/L.

Executive summary:

The study was performed as a limit test at the concentration 100 mg/L according to OECD 202. A total of 20 Daphnia magna (5 per replicate) were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted. The treatment showed no toxicity. None of the animals were immobilised in the control nor in the test solutions.

The following results were determined:

48h-NOEC≥100 mg/L

48h-LOEC > 100 mg/L

24h-EC50 > 100 mg/L

48h-EC50 > 100 mg/L

Description of key information

L-Histidine is not toxic to Daphnia magna. The EC50 value is > 100 mg/L and NOEC ≥100 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

For this endpoint, one study in which short-term toxicity to Daphina magna is assessed, is available. The study was performed as a limit test at the concentration 100 mg/L according to OECD 202. A total of 20 Daphnia magna (5 per replicate) were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted. The treatment showed no toxicity. None of the animals were immobilised in the control nor in the test solutions.

The following results were determined:

48h-NOEC≥100 mg/L

48h-LOEC > 100 mg/L

24h-EC50 > 100 mg/L

48h-EC50 > 100 mg/L