1,2-Ethandiylbis(oxy-2,1-ethandiyl)-dimethansulfonat

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 March 2022 - 19 April 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

2006

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

Regulation (EC) No 440/2008

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-[2-(2-hydroxyethoxy)ethoxy]ethanol,methanesulfonic acid

Cas Number:

80322-82-3

Molecular formula:

C8H18O8S2

IUPAC Name:

2-[2-(2-hydroxyethoxy)ethoxy]ethanol,methanesulfonic acid

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Oxidane

impurity 2

Reference substance name:

1,2-Ethandiylbis(oxy-2,1-ethandiyl)-monomethanesulfonat

IUPAC Name:

1,2-Ethandiylbis(oxy-2,1-ethandiyl)-monomethanesulfonat

Test material form:

liquid

Details on test material:

Appearance: Dark yellow liquid
Batch No.: 01110008
Storage: -5 – 40 °C, container tightly closed, protected from light

Specific details on test material used for the study:

Batch no.: 01110008
Storage conditions: 2–8°C, protected from light

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Details on inoculum
- Source: Sludge from the aeration tank of the ARA Werdhölzli (CH-8048 Zürich), a municipal biological waste water treatment plant.
- Preparation of inoculum for exposure: The sludge was pre-conditioned for 6 days (aerated but not fed) to reduce the amount of O2 consumed by the blank controls. Therefore, the sludge was washed twice with tap water and once with test medium.
- Pretreatment: The activated sludge was used after sampling from the treatment plant without adaptation.
- Concentration of sludge: 30 mg/L dry matter in the final mixture.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

83.3 mg/L

Based on:

other: nominal test item concentration based on 100 mg ThOD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of test medium: A mineral salt medium was prepared according to the test guideline and used for sludge preconditioning and testing (except for the abiotic sterile control. Analytical grade
salts were dissolved in ultra-pure water to obtain the concentrations. The pH value of the test medium was adjusted to 7.4±0.2.
- Test temperature: 22±2°C, controlled at ±1°C, in a thermostat cabinet in the dark
- pH: 6.0-8.5
- Continuous darkness: yes, test bottles were in a thermostat cabinet.

TEST SYSTEM
- Test flasks: 510 mL glass bottles (tightly closed with manometric BOD measuring devices) containing a total volume of test solution of 200 mL. The bottles were equipped with stirring rods and butyl
rubber quivers which contain 2 pellets of sodium hydroxide each to absorb the produced CO2 from the head space.
- Test performed in duplicate (two test flasks)

After centrifugation, the sludge was suspended in test medium at 3-5 g/l dry matter and kept under constant aeration and stirring without feeding for 6 days, until test start. On the day of the test start, this sludge suspension was diluted down to 60 mg/l dry matter, i.e. twice as high as the final test concentration, as this suspension was diluted by a factor of two afterwards to obtain a final dry matter concentration of 30 mg/l in the test vessels.

CONTROL AND BLANK SYSTEM
B: Inoculum blank (two replicates)
P: Procedure control (two replicates): 60.1 mg/L Sodium benzoate (100 mg ThOD/L)
A: Abiotic sterile control (one replicate): 83.5 mg/L test item (101 mg ThOD/L)
X: Toxicity control (one replicate): 84.0 mg/L test item and 60.1 mg/L Sodium benzoate (total 201 mg oxygen demand/L)

SAMPLING
The test vessels were stirred by an inductive stirring system for a maximum test period of 28 days. During the test the O2 uptake was continuously measured with a manometric BOD measuring device. Temperature was recorded with a data logger.
At the end of the test, the pH was measured in all flasks except the abiotic sterile control (A).
Total elimination was determined in each test vessel (test suspension, blank and procedure control) based on the theoretical carbon content and the analysis of the dissolved organic carbon (DOC) concentrations at the end of the test.

STATISTICAL METHODS:
Values of % degradation were calculated for each test flask and day. The arithmetic mean of % degradation in each test flask on each day was calculated.

Reference substance

Reference substance:

other: Sodium benzoate CAS 532-32-1

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

19

Sampling time:

28 d

Remarks on result:

other: test flask 1 after 28 d: 18% test flask 2 after 28 d: 19%

Details on results:

The biodegradability of Triethylene glycol dimethanesulfonate based on O2 consumption was calculated to be 19% after 28 days as compared to the theoretical oxygen demand (ThOD).
The biodegradation reached 18% at the end of the 10-d window.

The respective concentrations of organic carbon at the beginning (theoretical value based on the test item’s carbon content and the test concentration, as mg TOC/L) and at the end of the test (mean
measured value of the two replicates, as mg DOC/L) were, respectively:
- test units: 26.8 (theoretical value calculated based on the carbon content and the test concentration) and 23.2 (mean of two replicates)
- blank control: 0 and 0.954 (mean of two replicates)
- procedure control: 34.6 (theoretical value calculated based on the carbon content and the test concentration) and 1.27 (mean of two replicates)

The total elimination calculated based on dissolved organic carbon (DOC) measurements reached 17% for Triethylene glycol dimethanesulfonate and 99% for sodium benzoate, respectively.

Triethylene glycol dimethanesulfonate did not reach the pass level of 60% biodegradation in the manometric respirometry test within the 10-day window and therefore cannot be termed as readily biodegradable.

Any other information on results incl. tables

Procedure control:

The procedure control sodium benzoate reached 80% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

Toxicity control:

At the applied initial test concentration of 84.0 mg/L the test item was not judged to have any inhibitory effect on the microbial population, since the biodegradation of the mixture (test item + reference item sodium benzoate) exceeded 25% within 14 days.

 

Abiotic steril control:

Triethylene glycol dimethanesulfonate was not abiotically degraded (by processes using O2) during the whole test period of 28 days in the absence of microorganisms as confirmed by the lack of significant oxygen consumption.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

A 28-d ready biodegradability test (OECD 301F, Manometric Respirometry Test) using activated sludge of a municipal sewage treatment plant indicated that Triethylene glycol dimethanesulfonate (CAS no. 80322-82-3) did not reach the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window and, therefore, cannot be termed as readily biodegradable.

Executive summary:

The biodegradability of Triethylene glycol dimethanesulfonate (CAS no. 80322-82-3) exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions following the OECD guideline 301 F. The biodegradation was assessed based  on O2 consumption compared to the  theoretical oxygen demand ThOD.

 

Based on O2 consumption the biodegradation of Triethylene glycol  dimethanesulfonate was calculated to be 19% of ThOD after 28 days and reached  18% at the end of the 10-d window (i.e. 
within 10 days after attainment of 10%  degradation).

 

The procedure control with sodium benzoate reached a biodegradation of  80% after 14 days thus confirming  suitability of inoculum and test conditions.

 

Based on the determination of the DOC at the end of the test, the total elimination  was calculated to be 17% for Triethylene glycol dimethanesulfonate and 100% for sodium benzoate. This data is in line with  the degradation calculated based on O2  consumption.

 

Triethylene glycol dimethanesulfonate did not reach the pass level of 60% biodegradation in the manometric  respirometry test within the 10-day  window and therefore cannot be termed  as readily biodegradable.

 

All validity criteria were fulfilled.