Reaction products of alkenyl dihydrofuran-2,5-dione and polyisoalkenyl dihydro-2,5-furandione with alkylene glycol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: 259 K
- Boiling point: 567 K (decomposes)
- Vapour pressure: 1.2 x 10-8 Pa at 25 °C
- Water solubility (under test conditions): Unable to determine. Test item formed an emulsion with water in all proportions tested (between 1 and 100 g/L)
- log Pow: > 6.0

OTHER PROPERTIES (if relevant for this endpoint)
- Adsorption characteristics: Log Koc < 1.77
- Toxicity to microorganisms: Bacterial Respiratory Inhibition (OECD 209): EC50 = 390 mg/L

Oxygen conditions:

aerobic

Inoculum or test system:

other: mixed population of activated sewage sludge micro-organisms

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms were obtained from 10 different sampling sites around the UK, as follows:
a) City domestic sewage plants (x3)
i) Liverpool
ii) Belper, Derbyshire
iii) Bristol
b) Industrial sewage plant (x1)
i) Derby
c) River samples (x3)
i) River Mersey
ii) River Trent
iii) River Severn
d) Lake Water (x1)
i) Allestree Lake, Derby
e) Sea Water Samples (x2)
i) Skegness
ii) Southport

The sample types and volumes sampled from each site were as follows:
a) City sewage: 1 litre of return sludge at each sewage disposal plant
b) Rivers, lake and sea: 1 litre of surface water and 1 litre of surface soil on the bank/beach which is in contact with the atmosphere.

The samples were mixed thoroughly and allowed to settle. The floating foreign matters was removed and the supernatant filtered through a Whatman GF/A filter paper. The filtrate was then mixed with approximately 2 litres of supernatant removed from a previously established culture and transferred to a culture vessel. The pH of the culture mix was adjusted to 7.0 +/- 1.0 with sodium hydroxide or phosphoric acid and constantly aerated via a narrow bore glass pipette ata temperature of 24 deg. C.
The culture was allowed to settle daily for approximately 30 minutes and approximately 1/3 of the volume of the supernatant removed. An equal volume of 0.1 % synthetic sewage was added and the aeration re-started. Sythetic sweage was prepared by dissolving glucose, peptone and monopotassium phosphate in deionised water at a concentration of 0.1 % w/v. The pH of thesynthetic sewage and culture mix was adjusted daily to within the range 7.0 +/- 1.0 with sodium hydroxide or phosphoric acid.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

DOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

Preparation of culture medium: Deionised water purified by reverse osmosis was aerated and allowed to stand for 23 hours at 21 deg C to give a dissolved oxygen concentration of 8.90 mg O2/L.
To 1 L of water was added 3 mL each of solutions 1-14
Solution 1: K2HPO4 21.75 g/L; KH2PO4 8.50 g/L; Na2HPO4.12H2O 44.6 g/L; NH4Cl 1.70 g/L
Solution 2: MgSO4.7H2O 22.50 g/L
Solution 3: CaCl2 27.50 g/L
Solution 4: FeCl3.6H2O 0.25 g/L
Preparation of seeded dilution water: determination of the suspended solids level of the activated sludge culture was carried out according to the method given in JISK 0102-1981. The suspended solids (ss) concentration of the culture was determined to be 2100 mg ss/L. Seeded dilution water was prepared by the addition of 159 mL of the activated sludge culture to 10 L of culture medium to give a suspended solids level of approximately 33.38 mg ss/L, so that on subsequent dilution in the preparation of the test series, a suspended solids level of 30 mg ss/L was obtained.
For the preparation of the control vessel, the seeded dilution water was further diluted by the addition of deionised water to give a suspended solids value of 30 mg ss/L.
Preparation of test concentrations: The following test concentrations were prepared and incubated in 500 mL glass bottles.
1. One bottle containing inoculated culture medium only to act as the control. This bottle contained 500 mL of seeded dilution water with 30 mg ss/L.
2. Three replicate bottles containing inoculated culture medium and the test material at 100 mg/L.
3. One bottle containing the test material in deionised water alone at 100 mg/L.
4. One bottle containing the inoculated culture medium and the standard material, aniline at a concentration of 100 mg/L.
All control, test and standard amterial vessels were placed in the CES Multi-Channel Aerobic Respirometer.
The test was conducted in darkness at a temperature of 25 +/- 0.1 deg C.

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

ca. 38

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

ca. 42

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

28 d

Results with reference substance:

The standard material, aniline, attained 51 % degradation, calculated from the oxygen consumption values, after 7 days, 65 % after 14 days and 79 % after 28 days confirming the suitability of the inoculum and the culture conditions. Aniline obtained 100 % degradation calculted from the results of the DOC analyses.

Results tables and figures are attached.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The ready biodehradability of the test material was assessed in accordance with OECD Guideline 301C. The test material cannot be considered to be readily biodegradable under the strict terms of OECD TG 301C given that the degradation rates calculated from the oxygen consumption values were less than 60%.

Executive summary:

Introduction

A study was performed to assess the ready biodegradability of the test material in an aerobic aqueous medium.

Method

The method followed that described in OECD TG 301C "Ready Biodegradability; MITI Test" referenced as Method C.4 -F of Commission Directive 92/69/EEC. The test material was prepared as an aqueous dispersion at a final concentration of 100 mg/L, inoculated with micro-organisms from a laboratory culture originating from 10 different sites throughout the UK and incubated in the dark at 25 +/-0.1 deg C for 28 days. The degradation of the test material was assessed by the measurements of oxygen consumption, DOC analyses on days 0 and 28 and compound specific analyses on days 0 and 28. Control solutions with inoculum and the standard material, aniline, were used for validation purposes.

Results

The test material attained a mean of 38% degradation calculated from oxygen consumption values after 28 days. The mean degradation rate from the DOC analyses was 42%. The mean degradation rate from the residual test material analyses was 100 %. The test material cannot be considered to be ready biodegradable under the strict terms and conditions of OECD TG 301C as the degradation rate calculated from the oxygen consumption values was < 60%.

Description of key information

The ready biodegradability of the test material was assessed in accordance with OECD Guideline 301C.  The test material cannot considered to be readily biodegradable under the strict terms of the OECD TG 301C given that the degradation rates calculated from the oxygen consumption values were less than 60 %.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodehradability of the test material was assessed in accordance with OECD Guideline 301C.  The test material cannot be considered to be readily biodegradable under the strict terms of OECD TG 301C given that the degradation rates calculated from the oxygen consumption values were less than 60%.

No study is available for the substance itself, however a study is available for the read-across substance, Ethylene glycol, reaction products with polyisobutenyl succinic anhydride and hexadecenyl succinic anhydride, salts with dimethylethanolamine.

A study was performed to assess the ready biodegradability of the this material in an aerobic aqueous medium. The method followed that described in OECD TG 301C "Ready Biodegradability; MITI Test" referenced as Method C.4 -F of Commission Directive 92/69/EEC. The test material was prepared as an aqueous dispersion at a final concentration of 100 mg/L, inoculated with micro-organisms from a laboratory culture originating from 10 different sites throughout the UK and incubated in the dark at 25 +/-0.1 deg C for 28 days. The degradation of the test material was assessed by the measurements of oxygen consumption, DOC analyses on days 0 and 28 and compound specific analyses on days 0 and 28. Control solutions with inoculum and the standard material, aniline, were used for validation purposes.

The test material attained a mean of 38% degradation calculated from oxygen consumption values after 28 days. The mean degradation rate from the DOC analyses was 42%. The mean degradation rate from the residual test material analyses was 100 %. The test material cannot be considered to be ready biodegradable under the strict terms and conditions of OECD TG 301C as the degradation rate calculated from the oxygen consumption values was < 60%.