(Benzyloxycarbonyl)methyl 4-(1-Butyl-5-cyano-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridylazo)-benzoate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From October 25th, 2002 to November 5th, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

1984

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Yellow 6314-PPT

IUPAC Name:

Yellow 6314-PPT

Test material form:

solid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

Due to the low water solubility of the test item, a supersaturated dispersion of the test item with a loading rate of nominal 100 mg/l was continuously stirred at room temperature in the dark over 3 hours. Then the dispersion was filtered. The undiluted filtrate with the maximum concentration of dissolved test item was used as the only test medium. Additionally, a control was tested in parallel.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Hardness:

24 mg CaCO3 / l

Test temperature:

22-23 °C

pH:

7.9-8.5 undiluted filtrate
7.9-8.4 control

Nominal and measured concentrations:

Nominal 100 mg/l as loading rate

Details on test conditions:

Cell density at t = 0 h: 10^4 cells/ml

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

The test item had clearly no inhibitory effect on the growth of Scenedesmus subspicatus during the exposure period of 72 hours at a loading rate of 100 mg/l (mean measured test item concentration of 1.8 μg/l). This test concentration was therefore determined as the 72-hour NOEC (highest concentration tested without toxic effects after a test period of 72 hours). The NOEC might even be higher but concentrations in excess of the loading rate of 100 mg/l have not been tested, due to the low water solubility of the test item in the used test water.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item had no toxic effect on the algae up to its solubility limit in test water.