Dimethyl acetylsuccinate

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:

10 May 2010 to 18 August 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl acetylsuccinate

EC Number:

233-897-4

EC Name:

Dimethyl acetylsuccinate

Cas Number:

10420-33-4

Molecular formula:

C8H12O5

IUPAC Name:

dimethyl 2-acetylsuccinate

Details on test material:

Batch manufactured and supplied by: DSM Fine Chemicals, Austria Nfg GmbH & Co KG, St.-Peter-Straße 25, P.O. Box 933, 4021 Linz / Austria
Test Item: Dimethylacetylsuccinate
Common Name: DMAS
CAS No.: 10420-33-4
Chemical Name (IUPAC): (+/-)Acetylsuccinicaciddimethylester
Physical Appearance: Solid
Purity as per Certificate of Analysis: 97.8%
Batch No.: LEDM5A1003
Manufactured Date: Dec. 2009
Expiry Date: not applicable
Retest Date: Dec. 2011
Recommended Storage Condition: Ambient (+18 to +36ºC)
Note: Date of receipt of test item at test facility: 29.03.2010
Test Item code by test facility: D011-05

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: Secondary effluent from a sewage treatment plant (predominantly domestic)

Details on inoculum:

Secondary effluent collected from a treatment plant receiving predominantly domestic sewage was used as the inoculum. A fresh sample of effluent was collected from the treatment plant and was kept aerobic during transport. This effluent was allowed to settle for one hour and decanted. The decanted effluent was then used in the test.
- Source of inoculum: Community Sewerage Plant; Bharath Electronics Limited; Vidyaranyapuram, Bangalore; INDIA
- Pretreatment: The decanted effluent was preconditioned by aerating for 6 days at 22 to 23 °C.
- Initial cell/biomass concentration: the bacterial population in the inoculum was determined as colony forming units (CFU/mL) by diluting the inoculum up to 10 to the power of -4 dilution and then plating on nutrient agar plates.The bacterial population in the inoculum was 6.5 x 10 to the power of 7 CFU/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

33.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral medium as described in the guideline.
For details please see additional background material: Key. Indrani 2010. Ready Biodegradability - CO2 Evolution Test Tables and Figures.pdf
- Additional substrate: no.
- Solubilising agent (type and concentration if used): no
- Test temperature: 22 to 23°C
- pH: the pH of the test medium (without substance) was in the range of 7.53 to 7.54; the pH of the test media at the end of the test was between 7.90 and 7.99.
- pH adjusted: no
- Continuous darkness: the test was conducted under diffuse light.
- Other: The bacterial population in the inoculum was 6.5 x 10 to the power of 7 CFU/L. 300 mL per 3L were used.

TEST SYSTEM
Culturing apparatus: 5 L flasks.
- Number of culture flasks/concentration: 2 negative control flasks, 2 test substance flasks, 1 positive control flask, 1 toxicity control flask.
Each vessel was then fitted with a stopper holding an air inlet tube reaching below the liquid surface and an air outlet just below the stopper. The outlet of each test flask was connected to the inlet of three gas absorption bottles in series, each containing 100 mL of 0.0125 M barium hydroxide solution. The outlet of the last absorption bottle was left open.
The test vessels were continuously flushed for 28 days with carbon dioxide free air. Once a week, the flow rate of carbon dioxide free air was checked using the bubble flow meter.
The residual concentrations of barium hydroxide in the gas absorption bottles nearest to the test vessels were determined at approximate intervals of every second or third day during the first 10 days and then at least every fifth day until Day 29 by titrating with 0.05 M HCl. Following the removal of the first gas absorption bottle, the second was connected to the test vessel and a bottle containing fresh barium hydroxide was connected to the outlet of the bottle at the end of the series.
On Day 28, the pH of the test suspensions was recorded and 1 mL of concentrated hydrochloric acid was added to each flask to drive off dissolved inorganic carbon. The contents of the vessels were then aerated overnight and the final titrations were carried out on Day 29.
On Day 29, the aeration was stopped. All the barium hydroxide absorption bottles were disconnected and were titrated for the production of carbon dioxide.

SAMPLING
- Sampling frequency: The CO2 evolution was determined on Days 2, 4, 7, 10, 14, 18, 22, 25 and 28/29.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes, containing test substance and positive reference substance.
- Other: Positive reference substance.

STATISTICAL METHODS: no.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

None.

Test performance:

No unusual observations were made.

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

13.28

Sampling time:

2 d

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

55.56

Sampling time:

10 d

% Degradation 3

Parameter:

% degradation (CO2 evolution)

Value:

70.55

Sampling time:

14 d

% Degradation 4

Parameter:

% degradation (CO2 evolution)

Value:

94.49

Sampling time:

28 d

Details on results:

The cumulative CO2 production by mixtures containing only Dimethylacetylsuccinate had achieved 94.49 % degradation of test item during the treatment period. Dimethylacetylsuccinate had biodegraded by 13.28 % at Day 2, 55.56 % at Day 10 and 70.55 % at Day 14. Based on the pass levels (60 % bio-degradation in the 10-day window period), the test item is considered as readily biodegradable. During the test period of 28 days 94.49 % degradation was achieved.

For more details please see additional background material: Key. Indrani 2010. Ready Biodegradability - CO2 Evolution Test Tables and Figures.pdf

BOD5 / COD results

Results with reference substance:

Sodium benzoate had biodegraded by 33.09 % at Day 4 and 81.34 % by Day 14, meeting the validity criteria of the test.

Any other information on results incl. tables

For more details please see additional background material: Key. Indrani 2010. Ready Biodegradability - CO2 Evolution Test Tables and Figures.pdf

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Cumulative CO2 production by the mixtures containing Dimethylacetylsuccinate had achieved 13.28 % degradation after 2 days, 55.56 % degradation after 10 days, 70.55 % degradation after 14 days and 94.49 % degradation after 28 days. Substances are considered to be readily biodegradable in this test if CO2 production is equal to or greater than 60 % of the theoretical value. This value has to be reached in a 10-d window after reaching 10 % of ThCO2 production and within the test period. Since
94.49 % degradation was achieved during the test period of 28 days, Dimethylacetylsuccinate is considered to be readily biodegradable.

Executive summary:

The present study was conducted to determine the ready biodegradability of Dimethylacetylsuccinate. The ready biodegradability was tested using the CO₂Evolution Test (Modified Sturm Test) as per the OECD Guideline No. 301B.

The test item was added to two test vessels at the concentration of 33.3 mg/L of mineral medium [equivalent to 17.00 mg Carbon (C)/L]. Two control treatments containing only the inoculum, one positive control treatment containing inoculum plus reference standard (sodium benzoate), and one toxicity control treatment containing the inoculum plus test item and reference standard were also tested. All the treatments were prepared with inoculum from a secondary effluent treatment plant receiving predominantly domestic sewage.

Treatment mixtures were aerated for 29 days with carbon dioxide (CO₂) free air. The CO₂ released by each treatment mixture was trapped in a series of bottles containing barium hydroxide, which were connected to the outlet of each test vessel. The residual barium hydroxide was measured on the 2, 4, 7, 10, 14, 18, 22, 25 and 29 days after the initiation of the test by titration. The pH of the treatment mixtures was measured on Day 28.

Sodium benzoate had biodegraded by 33.09 % at Day 4 and 81.34 % by Day 14 in the absence of Dimethylacetylsuccinate meeting the validity criteria of the test. Test mixture containing sodium benzoate and Dimethylacetylsuccinate had biodegraded by 63.77 % at Day 14 showing that Dimethylacetylsuccinate was not inhibitory at this concentration.

The cumulative CO₂production by mixtures containing only Dimethylacetylsuccinate had achieved 94.49 % degradation of test item during the treatment period. Dimethylacetylsuccinate had biodegraded by 13.28 % at Day 2, 55.56 % at Day 10 and 70.55 % at Day 14. Based on the pass levels (60 % bio-degradation in the 10-day window period), the test item is considered as readily biodegradable. During the test period of 28 days 94.49 % degradation was achieved.