N-(N6-trifluoroacetyl-L-lysyl)-L-proline

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000-09-04 to 2000-10-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

1984

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 10, 100, 1000 mg/L
- Sampling method: Prior to the actual biological test, three concentrations of the test substance (10, 100, 1000 mg/L) covering the range of the test concentrations were analysed after 0 hours and 72 hours under test conditions for stability control.
- Sample storage conditions before analysis: not reported

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
-For the preparation of the stock solution, 2.33 g/L of the test substance were equilibrated in deionzed water. The resulting solution served as stock solution with a concentration of 2 g/L based on main product.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: Scenedesmus subspicatus (CHODAT (86.81 SAG))
- Age of inoculum (at test initiation): A preculture is withdrawn from a stock culture by transfer 3 days prior to the beginning of the test. From this preculture the test cultures are inoculated at a cell density of approximately 20,000 cells/mL.

ACCLIMATION
- Culturing media and conditions (same as test or not): same as test
- Any deformed or abnormal cells observed: not reported

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23.6- 23.9 °C in an environment chamber

pH:

at the beginning of the test: 6.6 - 8.4
at the end of the test: 6.9 - 10.0

Nominal and measured concentrations:

nominal: 15, 30, 60, 120, 250, 500, 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: The algae were cultured in sterile-aerated Erlenmeyer on light benches.
- Initial cells density: 20.000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Light intensity and quality: approximately 6000 - 1.0000 lux, white


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: cspectrophotometer

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: 10, 100, 1000 mg/L

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present test which was conducted according to OECD guideline 201 (1984), the EC50 value and the NOEC for growth rate is > 1000 mg/L for the test item.

Description of key information

In a test conducted according to OECD guideline 201 (1984), algae were treated with ε-trifluoracetyl-L-lysyl-L-proline (TFA-Lys-Pro) up to a concentration of 1000 mg/L for 72h. The EC50 value and the NOEC for growth rate is considered to be > 1000 mg/L for the test item (nominal concentration).

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

1 000 mg/L