Sodium 1,2-diisobutoxycarbonylethanesulphonate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

OECD 301 Enhancement: Prolongation of the test to day 60

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Date of study plan revision: June 28, 2019, Completion of study: September 30, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

enhanced to 60 days

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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: EOC surfactants, batch 1902154183
- Purity, including information on contaminants, isomers, etc.: 49.0% (100 – 51.0%; according to Coa)

APPEARANCE
-Water soluble, milky and viscous appearance at 20-35°C

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Well closed container, at 8 - 30°C.
- Expiry date: 13 May 13, 2020

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Fresh samples of activated sludge are withdrawn on July 10th, 2019 from the sewage treatment plant Ruhrverband Kläranlage, Sunthelle 6, 57392 Schmallenberg, Germany, which is mainly fed with municipal wastewater.
The samples were 2mm sieved after the arrival at the laboratory, washed once with mineral medium and kept aerobic until use. The concentration of suspended solids was measured in the sludge. The concentration was adjusted to 3.9 g/L and verified by dry mass measurement. The concentration used in the test was 29.6 mg dry mass/litre (7.39 mg dry mass/250 mL).

Duration of test (contact time):

60 d

Initial conc.:

55.3 mg/L

Based on:

ThOD

Initial conc.:

80 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

A measured volume of inoculated mineral medium, containing a known concentration of test item (giving 50 - 100 mg ThOD/L) as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature of 22 °C ± 1°C for up to 28 days. In this study, the test item concentration is 80 mg test item/L equivalent to 55.3 mg ThOD/L. The consumption of oxygen is determined by measuring the quantity of oxygen (produced electrolytically) required to maintain constant gas volume in the respirometer flask. Evolved carbon dioxide is absorbed in a suitable absorbent. The amount of oxygen taken up by the microbial population during biodegradation of the test item (corrected for uptake by blank inoculum, run in parallel) is expressed as a percentage of ThOD.

Reference substance:

benzoic acid, sodium salt

Test performance:

The solution of the reference substance in the mineral medium equivalent to a concentration of 100 mg/L was prepared using a stock solution (10 g/L). The test item in the original shipment vessel was kept for 15 minutes at 35°C in a water bath and shaked in regular intervals manually. Afterwards, the test item was liquid and transparent. Immediately, the required amount to ensure a final concentration of 80 mg/L (20 mg / 250 mL) of test item was added directly on a weight basis via Teflon discs to the test vessels. Subsequently, the mineral medium was added to the vessels. Further flasks with mineral medium only were prepared for inoculum controls. A further solution containing both test and reference item at the same concentrations as in the individual solutions (80 mg/L and 100 mg/L, respectively) was prepared to determine the possible toxicity of the test item.
Before test start the pH values of all solutions are determined and adjusted to 7.4 ± 0.2 with H2SO4 (50 g/L). The vessels were allowed to reach the desired temperature and were inoculated with prepared activated sludge to give a concentration of suspended solids not greater than 30 mg/L (in fact 29.6 mg/L). The total volume of solution was 250 mL in 500 mL respirometer flasks. The solutions were stirred during the whole test duration. In this way, dispersion of the test item and the contact between inoculum and test item was maximized. Twice a week the correct incubation temperature of the water bath and an adequate stirring were checked. At the end of the test the pH values of all solutions were determined (Table 1).
The test was run for 28 days, in darkness at 22°C ± 1°C in a water bath. The consumed oxygen is replaced by electrolytically generated oxygen

Key result

Parameter:

% degradation (O2 consumption)

Value:

70

St. dev.:

9

Sampling time:

28 d

Results with reference substance:

No inhibitory effects of the test item were observed: 78%. i.e., more than 25% degradation was determined on day 14 days in the toxicity control.

Validity criteria fulfilled:

yes

Remarks:

(1) The percentage degradation of the reference item was average 90.3% and hence exceeded the pass level of 60% by day 14, (2) with 16%, the difference of extremes of replicate values on day 28 was inside the range of 6.0 - 8.5.

Interpretation of results:

readily biodegradable

Conclusions:

In conclusion, Sodium 1,2-diisobutoxycarbonylethanesulphonate is readily biodegradable. The 10-day window was met by one replicate (63.1%). The results indicate that the test item is – in principle – capable to exceed the trigger for meeting the 10-day window.

Executive summary:

A study was performed at the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) to investigate the biodegradation of Sodium 1,2-diisobutoxycarbonylethanesulphonate over a 28-day period in a Manometric Respirometry Test according to OECD guideline 301 F (1992) [5] and EC method C.4-D (440/2008/EEC) [6]. The test medium was inoculated with microorganisms from a digester of a sewage treatment plant mainly fed with municipal wastewater.

The test solutions were stirred in closed flasks at 22 °C ± 1°C for 28 days. The rate of degradation was monitored by measuring the quantity of oxygen required to maintain a constant gas volume in the respirometer flasks over a 28-d period. The amount of oxygen taken up by the microbial population during biodegradation of the test item at a concentration of 80 mg/L (ThOD = 55.3 g), corrected for uptake by the blank inoculum run in parallel, was expressed as a percentage of the ThOD (theoretical oxygen demand). In order to check the procedure, sodium benzoate was used as a readily degradable reference item at a concentration of 100 mg/L, along with a toxicity control at 80 mg/L test item and 100 mg/L reference item.

The test fulfills the validity criteria of the guideline: (1) The percentage degradation of the reference item was average 90.3% and hence exceeded the pass level of 60% by day 14, (2) with 16%, the difference of extremes of replicate values on day 28 was less than 20%, (3) the oxygen uptake of the inoculum blank is < 60 mg/L in 28 days and the pH value was inside the range of 6.0 - 8.5.

No inhibitory effects of the test item were observed: 78%. i.e., more than 25% degradation was determined on day 14 days in the toxicity control.

The biodegradation of Sodium 1,2-diisobutoxycarbonylethanesulphonate was average 70% with a standard deviation of 9% at a concentration of 80 mg (55.3 mg ThOD) per liter and after 28 days. Biodegradation within the 10-day-window – which started at day 3 – was found to be average 58%. Biodegradation of one of the replicates reached 63.1% at the end of the 10-day window.

 

Description of key information

A key study for ready biodegradability is available The test was performed according to OECD 301 F and is valid according to the guideline criteria. After incubation for 28 days, 70 ± 9% (60-73-76%) of the test material was ultimately degraded. The 10-day window was met in one of three replicates. Conclusion: The substance is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

A study conducted by Anonymous (2005) was scored Klimisch 3 (not reliable) and the results are not used for this hazard assessment.