Fatty acids, C12-18 and C18-unsatd., 2-sulfoethyl esters, sodium salts

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-08-04 to 1994-08-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Short summary report of well conducted GLP study performed to OECD guideline 209

Data source

Reference

Reference Type:

other: short summary report incl. all critical study information e.g. OECD guideline, test item identity, result, study dates, etc.

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes

Remarks:

Test carried out to principles of GLP; but, the testing was carried out without inspection by the QA unit.The report was prepared in simplified summary form and contains no GLP certificate. Details of test material summarised in report but CofA not avail

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Batch: 1 (7.93) 331302
Purity: 68.7%
Impurities: 25% (coconut fatty acid and stearic acid)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: in the range of 62.5mg/L and 1000mg/L
- Sampling method: no data
- Sample storage conditions before analysis: no data

Test solutions

Vehicle:

no

Details on test solutions:

Due to low solubility, there was no stock solution (no solvent). The test item was weighed directly into the vessels. Better solubility was achieved in the test vessels by ultrasound treatment 30 minutes before the beginning of the test.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Amount of activated sludge used: 1600mg/L (dry weight)
Origin: Municipal wastewater treatment plant, Frankfurt/M-Sindlingen
Preparation: As specified in cited test guidelines
Acclimation state: Not acclimatised to the test substance or reference substance in the lab.

Study design

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

no data

Test conditions

Hardness:

no data

Test temperature:

20 +/- 2 degrees C

pH:

7.2 +/- 0.2

Dissolved oxygen:

no data

Salinity:

not applicable

Nominal and measured concentrations:

The concentrations of the test item were checked to be in the range of 62.5mg/L to 1000mg/L.

Details on test conditions:

The incubation with the test item was performed before the measurement of respiratory activity at 20 +/- 2°C over a period of 3 hours. The composition of the reaction medium is equivalent to that specified in the cited EEC Directive. The pH value of the culture solution was 7.2 +/- 0.2 and was determined prior to the depletion measurements. The sensitivity of the activated sludge was tested with a reference approach. A reference substance of 3,5-Dichlorphenol at the concentrations 5, 20 & 30 mg/L. As a control, an inoculated approach was used without addition of a test material. The control was filled with water to achieve a uniform volume.

The specified testing ranges were kept with both the reference substance as well as the control.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorphenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

ca. 639 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

meas. (not specified)

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: no data
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

The specified testing ranges were kept with both the reference substance as well as the control.

- Results with reference substance valid? no data
- Relevant effect levels: no data

Reported statistics and error estimates:

No data

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item was found to be harmless to the organisms in activated sludge.
The EC50 is in the range: >1000mg/L

Executive summary:

In a OECD 209 Activated sludge, respiration inhibition test, the inoculum (mainly domestic activated sludge) was exposed to the test item for 3 hours. Due to low solubility, there was no stock solution. The test item was weighed directly into the vessels. Better solubility was achieved in the test vessels by ultrasound treatment 30 minutes before the beginning of the test. The EC50 of the test item was found to be >1000mg/L, which means the test item is harmless to the organisms in activated sludge.