2-phthalimidoethyl N-[4-(2-cyano-4-nitrophenylazo)phenyl]-N-methyl-β-alaninate

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 18, 1996, to March 28, 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

1992

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

1984

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Version / remarks:

1989

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Red RA 10463

IUPAC Name:

Red RA 10463

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Beginning of study period, and end of study period (both with and without algae)

Test solutions

Vehicle:

yes

Details on test solutions:

Since the substance is practically insoluble in water (<9 µg/l), 0.1 ml/l acetone was used as a pre-solvent in the stock solution.

Test organisms

Test organisms (species):

Selenastrum sp.

Details on test organisms:

Selenastrum capricornutum

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22.5 - 23.0 °C, except for last 7 hours where it reached a maximum of 25.6 °C

pH:

8.3 - 9.3

Nominal and measured concentrations:

- Nominal concentration: 0.10, 0.18, 0.32, 0.56, 1.0 mg/l
- Measured concentrations: 0.59 mg/l at the start of the test; 0.072 mg/l at the end (with algae); 0.177 mg/l at the end (without algae)

Details on test conditions:

Initial cell density: 10^4 cells/ml

Reference substance (positive control):

yes

Remarks:

potassium dichromate, 0.18 - 3.2 mg/l

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The cell growth and growth rate of S. capricornutum was not inhibited by the test item, and was not found be significantly different from the control or solvent control groups during the period of the study. Concentration levels acutely toxic for S. capricornutum could not be reached, owing to the very low solubility of the test item in water (< 9 µg/l at 20.0 ± 0.5 °C). Therefore, the 72 hour EC50 values for growth inhibition and growth rate reduction were far beyond the maximum solubility in water.

Results with reference substance (positive control):

EC50 (72h, S. capricornutum) = 1.4 mg/l (growth inhibition)
EC50 (72h, S. capricornutum) = 2.3 mg/l (growth rate)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

EC50 (72h, S. capricornutum) > solubility limit
No difference in growth rate between treatment, control and solvent control groups, up to maximum nominal concentration of 1 mg/l