1,1'-Bicyclohexyl, 4-(1E)-1-propen-1-yl-4'-propyl-, (trans,trans)-

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:

Oct 17, 2019 - Feb 12, 2020

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))

Version / remarks:

22 Oct 2010

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Dry sludge concentration 3.30 g/L (corresponding to 1.65 g/L suspended solids in the test vessels)
Test concentration 1000 mg/L were weighed out directly in Erlenmeyer flasks
Replicates 3 Replicates
Vehicle None
Pre-treatment Stirring overnight in 200 mL ultrapure water at 400 rpm
Control Test medium without test or reference item
Replicates Triplicates at the beginning of the test and triplicates at the end of the test

Test Method Static
Test duration 3 h
Test vessels 500 mL Erlenmeyer flasks, DIN 12380
Nutrient solution Synthetic waste water according to OECD-Guideline 209
Test Medium Volume: 500 mL
Test Medium Composition: The test item was weighed out directly in Erlenmeyer flasks.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Test System: Activated sludge
Origin Municipal sewage treatment plant of 30982 Pattensen, Germany
Reason for the selection Non-adapted activated sludge from the sewage plant at Pattensen is well suited as it receives predominantly municipal sewage and hardly any industrial chemical waste.
Pre-treatment The sludge was washed twice with chlorine free tap water and adjusted to a dry sludge concentration of 3.0 g/L ± 10 %. The sludge was used within 24 h after sampling.
Date of receipt 2020-01-14

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21.2 °C

pH:

7.3-7.58

Dissolved oxygen:

Test samples : 6.69-7.69 mg O2/L
Control Samples: 5.56 - 7.45 mg O2/L

Nominal and measured concentrations:

test item: 1000 mg/L (nominal)
positive control: 58, 100, 180 mg/L

Reference substance (positive control):

yes

Remarks:

copper (II) sulphate pentahydrate

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

At a nominal test concentration of 1000 mg test item/L less than 10% inhibition was observed after three hours of incubation. The mean inhibition of respiration for the test item replicates was -3 %.
Therefore the NOEC is ≥ 1000 mg test item/L.

Results with reference substance (positive control):

copper (II) sulphate pentahydrate
EC50 = 75.2 mg/L

Validity criteria fulfilled:

yes

Conclusions:

At a nominal test concentration of 1000 mg test item/L less than 10% inhibition was observed after three hours of incubation. The mean deviation in respiration rate was -3 % at three replicates of 1000 mg test material.
The NOEC of the test item in the Respiration Inhibition Test with activated sludge with the test item is ≥ 1000 mg/L.

Executive summary:

Purpose

The purpose of the 3-hour toxicity test was to evaluate the influence of the test item on the activity of activated sludge by measuring the respiration rate under defined conditions. The respiration rate (oxygen consumption) of an aerobic activated sludge fed with a standard amount of synthetic sewage was measured in the presence of various concentrations of the test item after an incubation period of 3 hours.

Study Design

The test system was activated sludge of the municipal treatment plant of 30982 Pattensen, Germany. The test was carried out under static conditions with the limit test item concentration of 1000 mg/L. The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the control respiration rates.

Results

Toxicity of Test Item

At a nominal test concentration of 1000 mg test item/L less than 10% inhibition was observed after three hours of incubation. The mean inhibition of respiration for the test item replicates was -3 %

Therefore the NOEC is ≥ 1000 mg test item/L.

Toxicity of copper (II) sulphate pentahydrate

In order to check the activity of the test system and the test conditions a reference test was carried out with copper (II) sulphate pentahydrate as reference item and the reference toxicity was determined. The EC50-value for the reference item was 75.2 mg/L. The validity criteria of the test guideline were fulfilled.

Conclusion

The NOEC of the test item in the Respiration Inhibition Test with activated sludge with the test item is ≥ 1000 mg/L.

Description of key information

The test item had no inhibiting effects on the respiration rate of activated sludge up to and including 1000 mg/L.

The NOEC of the test item in the Respiration Inhibition Test with activated sludge with the test item is ≥ 1000 mg/L. The EC50 value was determined to be > 1000 mg/L.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

1 000 mg/L