lithium 3-((3,4-dicyanophenyl)sulfonyl)propane-1-sulfonate)

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study test phase 2012-05-28 to 2012-05-29. Study report date 2012-07-05.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Meets the criteria for classification as reliable without restriction according to klimisch et al (1997)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

lithium 3-((3,4-dicyanophenyl)sulfonyl)propane-1-sulfonate)

EC Number:

700-777-2

Cas Number:

667889-11-4

Molecular formula:

C11H9N2O5S2Li

IUPAC Name:

lithium 3-((3,4-dicyanophenyl)sulfonyl)propane-1-sulfonate)

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): S193308

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A nominal 5000 mg/L stock solution of the test material was prepared in deionised water. Test solutions were prepared by addition of a known volume of this stock solution to a total volume of 100ml reverse osmosis (RO) water, synthetic sewage and activated sludge. Two drops of antifoaming agent (Antifoam B Emulsion) were dispensed into each test flask. Nominal 10, 100 and triplicate 1000 mg/L concentrations of the test material were prepared together with two control culture flasks.
- Chemical name of vehicle: Water
- Evidence of undissolved material: The test material stock solution was observed to be a clear colourless solution of pH 7.6. The reference stock solution was also observed to be a clear colourless solution of pH 7.6.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Method of cultivation: Activated sludge was obtained from Totnes Sewage Works, Totnes, Devon, UK 1 day prior to the exposure of test and reference substances
- Preparation of inoculum for exposure: The activated sludge was settled and the supernatant decanted. The settled sludge was fed with 50ml of OECD synthetic sewage feed per litre of sludge per day and aerated at room temperature until it was used in the test.
- Initial biomass concentration: The total filterable solids concentration on the day of the test was determined to be 6161 mg/L.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

20 +/-2 deg. C

pH:

7.3-8.5

Details on test conditions:

TEST SYSTEM
- Test vessel: Flask
- Aeration: None (activated sludge aerated prior to test)
- No. of vessels per concentration (replicates): Nominal 10, 100, and tripliacte 1000 mg/L concentrations of test material
- No. of vessels per control (replicates): Two
- No. of vessels per reference (replicates): Five
- Biomass loading rate: Sufficient activated sludge was added to give final solids concentration of 1500 mg/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic sewage mixture described by OECD guideline 209, Activated Sludge, Respiration Inhibition Test (adopted 22 July 2010).


OTHER TEST CONDITIONS
- Adjustment of pH: The pH of one reference replicate was adjusted prior to the start of the test to 7.4.

EFFECT PARAMETERS MEASURED : The respiration rate (rate of oxygen uptake, mg/L/h) of each culture was measured after 3h.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

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

Effect concentrations 2

Duration:

3 h

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

Remarks:

respiration rate

Effect concentrations 3

Duration:

3 h

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

Remarks:

respiration rate

Effect concentrations 4

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

Remarks:

respiration rate

Details on results:

The respiration rate in the two control flasks were within 15% of each other. Therefore, the mean control respiration rate was used in calculation of the percentage inhibition, No oxygen consumption was seen in the abiotic control.

Results with reference substance (positive control):

- Results with reference substance valid: Yes
- Relevant effect levels: The 3h EC50 for the 3,5-DCP reference substance was estimated to be 3.1 mg/L. This was within the expected normal range of 2 to 25 mg/L indicating the sludge was responding normally and confirming the viability of the sludge.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test material on the respiration rate of activated sludge resulted in a 3h EC50 of >1000 mg/L. The NOEC after 3h exposure was 1000 mg/L. Therefore it is concluded that the test material at 1000 mg/L did not have a significant effect on the respiration rate of actived sludge micro-organisms in this study.

Executive summary:

Introduction

The study was performed to assess the effect of the test material on the respiration rate of activated sludge micro-organisms, typical of those found in domestc sewage treatment, in a respirometric test.

Results and Conclusions

The effect of the test material on the respiration rate of activated sludge resulted in a 3h EC50 of >1000 mg/L. The NOEC after 3h exposure was 1000 mg/L. Therefore it is concluded that the test material at 1000 mg/L did not have a significant effect on the respiration rate of actived sludge micro-organisms in this study.