Hydrogen [4-[[4-(diethylamino)phenyl][4-[ethyl[(3-sulphonatobenzyl)amino]-o-tolyl]methylene]-3-methylcyclohexa-2,5-dien-1-ylidene](ethyl)(3-sulphonatobenzyl)ammonium, sodium salt

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)

Version / remarks:

1988

Deviations:

not specified

GLP compliance:

no

Vehicle:

not specified

Details on test solutions:

- due to foam development of the substance a defoaming agent was added to the preparations

Test organisms (species):

activated sludge

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: OECD sludge, laboratory scale sawage treatment unit (10 L)
- Initial biomass concentration: 3 g/L dry weight

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

4 h

Hardness:

no data

Test temperature:

ca 25 °C

Nominal and measured concentrations:

50, 100, 500, 1000 mg/L nominal

Details on test conditions:

TEST SYSTEM
- Control: inoculum without Test substance
- Control : inoculum with reference inhibitor ATH (100 % inhibition)
- Sludge concentration (weight of dry solids per volume): 3 g/L dry weight

Reference substance (positive control):

no

Duration:

4 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of nitrification rate

Details on results:

- Nitrification rate: 2.6 mg/h*g oxidated N

Validity criteria fulfilled:

not specified

Conclusions:

Special Brilliant Blue FFR showed an EC 50 > 1000 mg/L after 4 hours (nitrification inhibition).

Executive summary:

A study was conducted according to ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms) to assess the toxicity of Special Brilliant Blue FFR towards microorganisms. The degree of inhibition on the nitrification performance of activated sludge was measured with several concentrations (50, 100, 500, 1000 mg/L nominal). A control with inoculum without test substance and a control with inoculum with reference inhibitor ATH (100 % inhibition) were run parallel. The temperature was ca. 25 °C. The nitrification rate was: 2.6 mg/h*g oxidated N.

Special Brilliant Blue FFR showed an EC 50 > 1000 mg/L after 4 hours (nitrification inhibition).

Description of key information

A study was conducted according to ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms) to assess the toxicity of Special Brilliant Blue FFR towards microorganisms. The degree of inhibition on the nitrification performance of activated sludge was measured with several concentrations (50, 100, 500, 1000 mg/L nominal). A control with inoculum without test substance and a control with inoculum with reference inhibitor ATH (100 % inhibition) were run parallel. The temperature was ca. 25 °C. The nitrification rate was: 2.6 mg/h*g oxidated N.

Special Brilliant Blue FFR showed an EC 50 > 1000 mg/L after 4 hours (nitrification inhibition).

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

Should read EC50 > 1000 mg/L