Reaction product of: 2-[[4-amino-2-ureidophenylazo]-5-[(2-(sulfooxy)ethyl)sulfonyl]]benzenesulfonic acid with 2,4,6-trifluoropyrimidine and partial hydrolysis to the corresponding vinylsulfonyl derivative,mixed potassium/sodium salt

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Yellow MGi 1301

IUPAC Name:

Yellow MGi 1301

Test material form:

solid

Test organisms

Test organisms (species):

activated sludge

Study design

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Nominal and measured concentrations:

10, 32, 100, 320 and 1000 mg/|

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Any other information on results incl. tables

ln comparison to the inoculum controls the respiration rate of the activated sludge was slightly to moderately inhibited by 15.4, 23.1 and 30.2 % al the three lower nominal YELLOW MGi 1301 concentrations of 10, 32 and 100 mg/|, respectively. At the two higher

nominal YELLOW MGi 1301 concentrations of 320 and 1000 mg/|, the respiration rate reached a plateau with an inhibition rate of 26.6 % for both concentrations. YELLOW MGi 1301 concentrations exceeding 1000 mg/l nominal were not tested. Visual assessment of the appearance of YELLOW MGi 1301 in the final test medium resulted in dark orange solutions without any undissolved particles up to the highest test concentration of 1000 mg/l.

From these inhibition rates, the 3-hour EC50 could not be quantified because up to the highest nominal test concentration of 1000 mg/l less than 50 % inhibition was noted after three hours contact time. Nevertheless, the 3-hour EC50 is clearly higher than 1000 mg/l nominal under the present test conditions. The 3-hour EC20 was calculated by linear regression analysis using the inhibition rates of the 100, 32 and 10 mg/l test concentrations, and was calculated lo be 20.2 mg/l nominal.

The 3-hour EC50 for the positive control 3,5-dichlorophenol, which was tested in the same way as the test article, was found to be 15.2 mg/l and is within the range of 5 - 30 mg/l recommended by the test guidelines; thus, confirming suitability of the activated sludge.

Applicant's summary and conclusion

Conclusions:

EC50 (3 h) > 1000 mg/l