(E)-3-(benzyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)propanenitrile

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:

08 September 1998 to 11 September 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to recent EU test guidance in compliance with GLP.

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Analysis of the only test concentration (8 mg/l) plus a control; additional analysis of the test concentration 8 mg/l without algal inoculum, at test start and after 72 hours of exposure.

Vehicle:

no

Details on test solutions:

To produce the only test concentration (8 mg/l), the test substance was weighed into water, treated in an ultrasonic bath for 1 hour and afterwards stirred for 24 hours on a magnetic stirrer. To remove undissolved particles, the resulting suspension was filtered using a folded filter of the pore size 7-12 um.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Species: Scenedesmus subspicatus CHODAT
Origin: Institute of Plant Physiology, University of Gottingen
Cultivation (stock cultures, precultures, test cultures): In a light chamber at 23 ± 2 °C and with a quantum flux which equals 120 μE/m-2s.
Water for dilution: deionised water

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

No post exposure observation period

Hardness:

Not reported.

Test temperature:

Not reported.

pH:

8.2 - 10.3

Dissolved oxygen:

Not reported.

Salinity:

Not applicable.

Nominal and measured concentrations:

8 mg/l (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 300ml
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionized water

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter] Microcellcounter

The test solutions are incubated for a period of 72 hours, during which the cell density in each is measured at every 24 hours. The inhibition of growth and growth rate in relation to a control is determined after 72 hours of incubation.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 3.75 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 3.75 mg/L

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.75 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.75 mg/L

Basis for effect:

growth rate

Details on results:

The above test result refers to a concentration of the test substance, which was calculated directly from analytically determined TOC values. According to the relevant product information, 1 mg/1 TOC equals to 1.5 mg/l of the test substance (structural formula: C22H19N502; molecular weight: 385.4 g/mole).

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

Not reported.

Validity criteria fulfilled:

yes

Conclusions:

No toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).

Executive summary:

Study data conducted to EU test guidance 92/69/EEC part C.3 and in compliance with GLP.

Study found no toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).

Description of key information

No toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

3.75 mg/L

Additional information

Study data conducted to EU test guidance 92/69/EEC part C.3 and in compliance with GLP.

Study found no toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).