Amines, C10-14-branched and linear alkyl, bis[2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]chromate(1-) (1:1)

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:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Amines, C10-14-branched and linear alkyl, bis[2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]chromate(1-) (1:1)

EC Number:

284-628-2

EC Name:

Amines, C10-14-branched and linear alkyl, bis[2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]chromate(1-) (1:1)

Cas Number:

84961-40-0

Molecular formula:

C32H22CrN10O8.C10-14H21-29NH2

IUPAC Name:

Amines, C10-14-branched and linear alkyl, bis[2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]chromate(1-) (1:1)

Test material form:

solid

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

The test substance was added directly to the test system.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

lnoculum: activated sludge from laboratory wastewater treatment plants fed with municipal and synthetic wastewater. The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated for 24 hours. 50 mL were added to a test volume of 250 mL to obtain a concentration of 1 g/L dry substance in the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

30 min

Test conditions

Test temperature:

20 ± 2 °C

pH:

6.8

Dissolved oxygen:

Oxygen concentration during aeration: > 2.5 mg/L
Oxygen concentration imidiately before measurement: > 6.5 mg/L

Nominal and measured concentrations:

Nominal: 1003 mg/L

Details on test conditions:

TEST SYSTEM
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 3
- No. of vessels per reference substance (replicates): 3

TEST MEDIUM / WATER PARAMETERS
8 mL/vessel 100-fold concentrated OECD Medium

OTHER TEST CONDITIONS
- Adjustment of pH: The pH value has been measured and adjusted to pH 7.0 - 8.0 before the addition of activated sludge.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 2

Key result

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 3

Duration:

30 min

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

No significant inhibition of respiration was measured up to the highest test concentration of 1000 mg/L.

Validity criteria
Deviation of blank controls < 15 %: yes
EC50 of 3,5-dichlorophenol in the range of 5 - 30 mg/L: yes
Test is valid: yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The inhibition of the degradation activity of activated sludge is not anticipated when introduced to biological treatment plants in appropriate low concentrations.