Reaction mass of 6-Chloro-2-{4[ethyl(2-hydroxyethyl)amino]phenyl}-1-methylbenzo[cd]indolium hydroxide and 6-chloro-2-[4-[ethyl(2-hydroxyethyl)amino]phenyl]-1-methylbenz[cd]indolium acetate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study completion date: 17 April, 1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Test substance: FAT 31064/F
Solubility: 50 g/L (insoluble in water)
Storage: Room temperature
Appearance: Solid

Vehicle:

no

Details on test solutions:

1, 3.2, 10, 32 and 100 mg/L

Test organisms (species):

anaerobic bacteria

Details on inoculum:

Test organism mixed culture of bacteria (sludge of a Husman apparatus)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

Study terminated after 3 h

Test temperature:

20.5 °C

Nominal and measured concentrations:

1, 3.2, 10, 32 and 100 mg/L

Details on test conditions:

Temperature: 20.5 °C
Estimation technique: O2-consumption, measured with an oxygen-sensitive electrode system: OXI DIGI 550.

Reference substance (positive control):

yes

Key result

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

The % inhibitions observed were 0.0, 4.0, 0.0, 4.5 and 15.7 % at concentrations of 1, 3.2, 10, 32 and 100 mg/L, respectively.

Results with reference substance (positive control):

The IC50 of the reference substance 3,5-Dichlorophenol is: 15 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The IC50 (3 h) of FAT-31064/F was found to be greater than 100 mg/L

Executive summary:

A toxicity study of FAT 31064/F to activated sludge was determined in a 3-hours respiration inhibition test according to OECD test guideline 209 following GLP. The test substance concentrations tested were 1, 3.2, 10, 32 and 100 mg/L.

The estimation technique used was O2 consumption measured with oxygen sensitive electrode system. The reference substance used was 3,5 -Dichlorophenol. The % inhibitions observed were 0.0, 4.0, 0.0, 4.5 and 15.7 % at concentrations of 1, 3.2, 10, 32 and 100 mg/L, respectively. Thus, the IC50 (3 h) of FAT-31064/F was found to be greater than 100 mg/L The IC50 (3h) of 3,5 -Dichlorophenol was found to be 15 mg/L.

Description of key information

In the key study, the toxicity of FAT 31064/F to activated sludge was determined in a 3-hours respiration inhibition test according to OECD test guideline 209 following GLP. The test substance concentrations tested were 1, 3.2, 10, 32 and 100 mg/L. The estimation technique used was O2 consumption measured with oxygen sensitive electrode system. The reference substance used was 3,5 -Dichlorophenol.The % inhibitions observed were 0.0, 4.0, 0.0, 4.5 and 15.7 % at concentrations of 1, 3.2, 10, 32 and 100 mg/L, respectively. Thus, the IC50 (3 h) of FAT-31064/F was found to be greater than 100 mg/L The IC50 (3h) of 3,5 -Dichlorophenol was found to be 15 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

100 mg/L