oligomeric Reaction products from Hydrogenation and Hydrolysation of Starch

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jan - Jun 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

473-690-8

EC Name:

-

Cas Number:

738602-93-2

Molecular formula:

not applicable for UVCB

IUPAC Name:

(2R,3R,4S,5S,6R)-2-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-6-(hydroxymethyl)oxane-3,4,5-triol; (2S,3R,5R)-4-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}hexane-1,2,3,5,6-pentol

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material: 4G08
- Purity, including information on contaminants, isomers, etc.: 54.2% (maltotriosyl glucoside

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature, away from direct sunlight

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 500.5 mg of the test substance were dissolved in 284 mL of tapwater using stirring and ultrasonic treatment
- Eluate: not applicable
- Differential loading: not applicable
- Controls: positive and negative controls
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): no organic solvent, emulsifier or diepersant used
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
- Test concentration separation factor: limit test, only one concentration tested
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none reported
- Other relevant information:

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: no
- Name and location of sewage treatment plant where inoculum was collected: ARA Ergolz II, Füllinsdorf, Switzerland
- Method of cultivation: see preparation of inoculum
- Preparation of inoculum for exposure: Based on the ratio of wet to dry weight, an aliquot of washed sludge was suspended in tapwater to obtain a concentraiton equivalaent to 3 g dry material per liter. During the holding period of two days prior to use, the sludge was fed daily with 50 mL synthetic waterwater per liter and was kept at room temperatur eunder continous aeration until use.
- Pretreatment: the sludge was washed twice with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated.
- Initial biomass concentration: 3 g dry material per liter

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

none

Test conditions

Hardness:

not stated

Test temperature:

20 °C

pH:

7.6 at start

Dissolved oxygen:

8.2 to 8.7 mg O2/L

Salinity:

not applicable

Conductivity:

not stated

Nominal and measured concentrations:

nominal 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 1000 mL glass flasks
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: glass ware, 1000 mL, 500 mL fill volume
- Aeration: continseuosly
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2 (inoculum control), 3 (positive control)
- No. of vessels per vehicle control (replicates): not applicable
- No. of vessels per abiotic control (replicates): none
- Sludge concentration (weight of dry solids per volume): 3.8 mg/L
- Weight of dry solids per volume of reaction mixture per unit of time: not applicable
- Nutrients provided for bacteria: not applicable
- Nitrification inhibitor used (delete if not applicable): none
- Biomass loading rate: not determined/not applicable
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water
- Particulate matter: not determined
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: not stated
- Light intensity: not stated
- Details on termination of incubation: samples were taken after incubation period and were not further aerated.
EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
dissolved Oxygen concentration was measured continuously for 10-15 min
TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable
- Justification for using fewer concentrations than requested by guideline:
- Range finding study
- Test concentrations: 1000 mg/L
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

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:

other: inhibition on repiration rate (oxygen consumption per minute)

Details on results:

The test item MG-60 had no inhibitory effect on the repiration rate of activated sludge after the incubation period of 3 hours at the test item concentration of 1000 mg/L

Results with reference substance (positive control):

The 3-hour EC 50 of the reference item 3,5-dichlorophenol was calculated to be 13 mg/L with 95 % confidence limits from 7.6 to 22 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item MG-60 had no inhibitory effect on the repiration rate of activated sludge after the incubation period of 3 hours at the test item concentration of 1000 mg/L

Executive summary:

The inhibitory effect of the test item MG-60 on the respiration rate of aerobic wastewater microorganisms of activated sludge was investigated in a 3-hour repiration inhibition test according to EU-Guideline C.11 and the OECD Guideline 209.

In accordance with the guidlines, a limit test was perormed testing one concentration of MG-60 of nominal 1000 mg/L to demonstrate that the test item has no toxic effect on activated sludge microortanims up to and including this concentration.