Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-[2-[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methylethyl]-.omega.-[2-[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methylethoxy]-

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:

2004-10-18 to 2004-11-16

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

Version / remarks:

April 4th 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 30th 1988

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

yes

Details on test solutions:

For the pre-test, a stock solution containing 200 mg test item/L in deionized water was prepared. After 10 minutes in the ultrasonic bath the emulsion didn't show any undissolved particles. The stock solution then was used to prepare solutions at the concentrations of 100,10, and 1 mg/L. The treatment of 1000 mg/L was prepared by adding the appropriate volume of the test item directly. In the main study, the test item was used directly.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from a biologic sewage treatment plant was used. The chosen plant treats mostly household sewage. The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, 67435 NW-Lachen-Speyerdorf.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

no

Hardness:

0.943 mmol/L

Test temperature:

20 ± 2 °C

pH:

8.17

Dissolved oxygen:

not specified

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

pre-test: 1, 10, 100, 1000 mg/L
main study: 1000 mg/L

Details on test conditions:

1. Test Vessels
Glass beakers were used as test vessels. They were cleaned before use. Narrow-neck glass bottles with flat bottoms were used as measuring flasks.

2. Preparation
The nutrient solution was freshly prepared; the inoculum was taken from its source, washed, aerated and the dry matter was determined. The stock solutions of test item and reference item were prepared.

3. Experimental conditions
Duration
Pre-Test: three hours
Replicates: one replicate/treatment
Control: one replicate before and one after measuring O2 concentrations in the test item replicates

Main-Study
Replicates: two replicates/treatment
Control: two replicates before, two between and two after measuring O2-concentrations in the reference and test item replicates
Water: tap water
Aeration: purified air, using Pasteur pipettes, flow approx. 0.75 L/min
Feeding: nutrient solution, 16 ml/vessel
Temperature: 20 ± 2 °C

Conduct of the study
16 mL nutrient solution were mixed with 284 mL water in the first control vessel, then 200 mL inoculum were added and the mixture was aerated. Five minutes later, the first treatment was prepared by mixing 16 mL nutrient solution with the appropriate amount of test item and adding water to give 300 mL. Then 200 mL inoculum were added and the mixture was aerated. The following reference, test item and control treatments were prepared likewise in five minute intervals. After three hours, the content of the first vessel was poured in a 250 mL narrow-neck bottle and the respiration rate was determined by measurement of the O2-concentration over a period of five minutes. The following vessels were measured likewise in five minute intervals.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenole

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

ca. 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: 95% CL n.d.

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

Remarks:

respiration rate

Remarks on result:

other: 95% CL n.d.

Details on results:

Validity
The reference item showed an EC50 of 8.2 mg/L in the main study, which is within the recommended range of 5 - 30 mg/L. The O2 consumption rates of the controls showed a variation of 3 % in the pre-test and 7 % in the main study, which is well below the recommended limit of 15%. In the main study, the values at the begin and at the end of the evaluated O2 measurements were within the recommended range of 6.5 - 2.0 mg/L.

Results with reference substance (positive control):

The EC50 of the reference item was determined as 8.2 mg/L (95% confidence interval: 6.4 - 10.2 mg/L), which lies within the recommended range of 5 - 30 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

Sika Härter LJ was tested for toxicity to microorganisms by determination of inhibition of the respiration of activated sludge according to OECD guideline 209 revealing a 3h EC50 of > 1000 mg/L and a NOEC 1000 mg/L.

Executive summary:

Sika Härter LJ was tested for toxicity to microorganisms by determination of inhibition of the respiration of activated sludge according to OECD guideline 209 and EU method C.11. Two valid experiments were performed. In the pre-test, the test item was tested using four concentrations (ranging from 1000 to 1 mg/L). Duration of the test was three hours. Activated sludge was used as inoculum. It was taken from a domestic sewage treatment plant and washed before usage. The dry matter was determined as 4.0 g suspended solids/L, giving a concentration of 1.6 g suspended solids/L in the test. As the pre-test was performed for range-finding only, no reference item was tested. No inhibition of the respiration of the activated sludge was detected in the treatments.

The main study was performed as a limit-test with a nominal concentration of 1000 mg/L. Conduct of the study was the same as in the pre-test. The dry matter of the activated sludge was determined as 4.1 g suspended solids/L, giving a concentration of 1.64 g suspended solids/L in the test. 3,5-Dichlorophenole was used as reference item. The EC50 of the reference item was determined as 8.2 mg/L (95% confidence interval: 6.4 - 10.2 mg/L), which lies within the recommended range of 5 - 30 mg/L. The following results for the test item Sika Härter LJ were determined:

NOEC 3h = 1000 mg/L

3h EC20 > 1000 mg/L

3h EC50 > 1000 mg/L

Description of key information

Sika Härter LJ was tested for toxicity to microorganisms by determination of inhibition of the respiration of activated sludge according to OECD guideline 209 revealing a 3h EC50 of > 1000 mg/L and a NOEC 1000 mg/L.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

1 000 mg/L

Additional information

Sika Härter LJ was tested for toxicity to microorganisms by determination of inhibition of the respiration of activated sludge according to OECD guideline 209 and EU method C.11. Two valid experiments were performed. In the pre-test, the test item was tested using four concentrations (ranging from 1000 to 1 mg/L). Duration of the test was three hours. Activated sludge was used as inoculum. It was taken from a domestic sewage treatment plant and washed before usage. The dry matter was determined as 4.0 g suspended solids/L, giving a concentration of 1.6 g suspended solids/L in the test. As the pre-test was performed for range-finding only, no reference item was tested. No inhibition of the respiration of the activated sludge was detected in the treatments.

The main study was performed as a limit-test with a nominal concentration of 1000 mg/L. Conduct of the study was the same as in the pre-test. The dry matter of the activated sludge was determined as 4.1 g suspended solids/L, giving a concentration of 1.64 g suspended solids/L in the test. 3,5-Dichlorophenole was used as reference item. The EC50 of the reference item was determined as 8.2 mg/L (95% confidence interval: 6.4 - 10.2 mg/L), which lies within the recommended range of 5 - 30 mg/L. The following results for the test item Sika Härter LJ were determined:

NOEC 3h = 1000 mg/L

3h EC20 > 1000 mg/L

3h EC50 > 1000 mg/L