Reaction mass of didodecyl 3,3'-thiodipropionate and dioctadecyl 3,3'-thiodipropionate and octadecyl 3-[[3-(dodecyloxy)-3-oxopropyl]thio]propionate

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988-11-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Non GLP study. Deviations from the updated OECD-guideline (adopted 2010). Instead a centrifuged sludge a settled sludge was used. Due to the expected low toxicity of the test substance, the substance was tested at one concentration (100 mg/L) in duplicate samples. The substance was not dissolved but distributed in the test medium. The sludge concentration in the test bottles was 2 g/L instead of 1.4 - 1.8 g/L.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

Settled sludge instead of centrifuged one. The substance was tested at one concentration (100 mg/L) in duplicate samples. The substance was not dissolved, but distributed in the test medium. Sludge concentration was 2 g/L.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Didodecyl 3,3'-thiodipropionate

EC Number:

204-614-1

EC Name:

Didodecyl 3,3'-thiodipropionate

Cas Number:

123-28-4

Molecular formula:

C30H58O4S

IUPAC Name:

didodecyl 3,3'-sulfanediyldipropanoate

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 20.5 rsp. 20 mg of the test substance were weighed and added to the test medium. The volume was adjusted to 200 mL with bidistilled water and aerated for 3 hours.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Source: Activated sludge collected from the sewage treatment plant of CH - 4153 Reinach on 28/11/88.
- Pretreatment: according to guideline
- Initial biomass concentration: 2.0 g/L
The sludge was separated from the aqueous layer by settling instead of centrifugation.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

None

Test conditions

Test temperature:

20 ± 2 °C

pH:

7.8

Nominal and measured concentrations:

102.5 and 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: BOD flasks with gas inlet
- Type: closed
- Material, size, headspace, fill volume: 250 mL (size)
- Aeration: None
- No. of organisms per vessel: 2 g/L
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): None
- Reference substance: 3,5-Dichlorophenol at 32, 10, and 3.2 mg/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated drinking water
- Medium: In accordance to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH: None

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Oxygen consumption per hour in mg/liter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Single concentration in duplicate
- Justification for using less concentrations than requested by guideline: Expected low toxicity of the test substance

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 100 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: IC20

Effect conc.:

> 100 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: IC80

Effect conc.:

> 100 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: None

Results with reference substance (positive control):

- Results with reference substance valid: Yes
- Relevant effect levels: Graphically determined IC50 = 12 mg/L

Any other information on results incl. tables

The inhibitions were calculated on the basis of the measured time dependent oxygen consumption of Blank and Test solutions.