REAKTIV-ORANGE DYPR 934

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-03-15 to 1999-03-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (Incubation time of 3 hours with permanent aeration instead of 30 minutes as recommended)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

Incubation time of 3 hours with permanent aeration instead of 30 minutes as recommended. Reason: Recommendation of the Umweltbundesamt.

Principles of method if other than guideline:

A defined quantity of activated sludge is mixed with synthetic medium and the respiratory rate is measured. This rate is compare to those measured in test preparations with various concentrations of the substance. In order to check the sensitivity of the activated sludge used, 3,5-dichlorophenol is used as a reference substance.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Details on test material:

-Name of test material (as cited in study report): Reaktiv-Orange DYPR934

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Test concentrations (mg/L) 100, 1000 and 10000
Test substance concentration in physico-chemical consumption and biological oxygen consumption = 10000mg/L (the physico-chemical oxygen consumption is carried out since some substances can also consume oxygen by chemical reactivity. In order to be able to tell the difference between physico chemical oxygen consumption and biological oxygen consumption (respiration), at least the maximum concentration is tested without activated sludge.
Test concentration of the activated sludge: 560 mg/L
- Sample storage conditions before analysis: According to the guideline
- Sampling: Direct weighing (according to SOP 2030-6600401-96 D)

Test solutions

Vehicle:

no

Details on test solutions:

Incubation time of 3 hours with permanent aeration instead of 30 min incubation time
Invitro/Bac:Biodegradability: Test for Inhibition of oxygen consumption
Bac: defined quantity of activated sludge (mix of different microorganisms, Wupper area water authority) mixed with synthetic medium, respiratory rate is measured
Reference substance 3,5-dichlorophenol
Nominal weights

Test organisms

Test organisms (species):

activated sludge

Details on inoculum:

Sludge from predominantly domestic sewage
Pretreatment: none
The test substance has been added to about 130 mL deionized water and stirred overnight before testing (equilibration phase)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Remarks on exposure duration:

With permanent aeration

Test conditions

Hardness:

15.4 mg CaCO3/L

Test temperature:

20±2

pH:

6,8

Salinity:

freshwater

Nominal and measured concentrations:

Nominal weights
The study is carried out with nominal weights. The test concentrations are not confirmed by chemicals analysis.
100, 1000 and 10000 mg/L
Test concentration of the activated sludge: 360 mg/L
Test substance concentration in physico-chemical oxygen consumption control (mg/L):
10 000

Details on test conditions:

A defined quantity of activated sludge is mixed with synthetic medium and the respiratory rate is measured. This rate is compare to those measured in test preparations with various concentrations of the substance. In order to check the sensitivity of the activated sludge used, 3,5-dichlorophenol is used as a reference substance.

Reference substance (positive control):

yes

Remarks:

3,5 dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none
- Effect concentrations exceeding solubility of substance in test medium: unknown

Results with reference substance (positive control):

- Results with reference substance valid yes
EC50 = 13 mg/L

Any other information on results incl. tables

Results

Toxicity to bacteria (test substance)	Reference substance
EC 50 > 10000 mg/l	EC 50 = 13 mg/l

 

Measured values of the test substance/control (according to SOP 2030-6600502 -96 D, 2030-0000104-98 D, 2030-0000402 -96, 2030-0000504-98 D)

	Test concentration [mg/L]	Initial concentration [mg/250 mL]	O2-start [mg O2/L]	O2-end [mg O2/L]	Time [min]	Temp [°C]	pH
Test Substance	100	25	6.4	3.7	8	20.3	8.0
	1000	250	6.4	3.8	8	20.3	8.0
	10000	2500	5.8	3.8	7	20.4	7.9
Control			5.4	3.7	8	20.1	7.9
Control			6.3	3.5	8	20.2	8.0
Physio-chemical consumption control	10000	2500	8.6	8.6	9	20.5	7.3

 

Study evaluation

Test concentration [mg/L]	Respiratory rate test substance [mg/l.h]	Phys.chem. O2–consumption [mg/l.h]	Respiratory rate -phys. Chem. - O2–consumption [mg/l.h]	Inhibition [%]
100	20.3	0.0 *	20.3	1.9
1000	19.5	0.0*	19.5	5.8
10000	17.1	0.0	17.1	17.4
		Comment relevant to result: Test concentrations are given as nominal concentrations and have not been confirmed by analytical methods. *The physico-chemical oxygen consumption has been determined. Therefore lower concentrations of the test substance cause no physico chemical oxygen consumption.
Control, mean	20.7
Control 1	20.3
Control 2	21.0

 Comments: Because of strong respiration of the activated sludge only 0.56 g/L ss were used.

The test substance has been added to about 130 mL deionized water and stirred overnight before testing (equilibration phase)

Measured values of reference substance

(according to SOP 2030 -6600502 -96 D, 2030-0000104-98 D, 2030-0000402 -96, 2030-0000504 -98 D)

	Test concentration [mg/L]	Initial concentration* [mg/250mL]	O2-start [mgO2/L]	O2-end [mgO2/L]	Time [min]	Temp [°C]	pH
Reference substance	5	2.5	6.0	3.9	7	20.1	7.9
	10	5	6.5	5.4	5	20.2	8.0
	20	10	7.8	7.1	7	20.2	8.1

 

Comments: *Volume added in mL of 3.5 Dichlorophenol stock solution (500mg/L) total volume 250 mL

Method : 50 % - inhibitory effects:

Test procedure: Respiratory inhibition of activated sludge

organisms according to D. Brown et al., Chemosphere, 10(3),

245-261 (1981 ), and conforming to OECD Guideline 209

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Toxicity to bacteria of Reaktiv Orange DYPR 934 to activated sludge: EC 50 > 10000 mg/L (Reference Substance: EC 50 = 13 mg/L)

Executive summary:

Toxicity to bacteria of Reaktiv Orange DYPR 934 to activated sludge: EC 50 > 10000 mg/L (Reference Substance: EC 50 = 13 mg/L)