Linseed oil, oxidized

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27-jan-2010 to 25-feb-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and to GLP principles.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap de Maaskant', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.

Treatment : The freshly obtained sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was 3.8 g/l in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (73 minutes) and the liquid was decanted for use as inoculum at the amount of 10 ml/l of mineral medium.

Duration of test (contact time):

28 d

Initial conc.:

15.5 mg/L

Based on:

test mat.

Initial conc.:

12 mg/L

Based on:

other: Total Organic Carbon (TOC in mg/L)

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: 1 litre mineral medium contains: 10 ml of solution (A), 1 ml of solutions (B) to (D) and Milli-RO water
Stock solutions of mineral components
A) 8.50 g KH2PO4; 21.75 g K2HPO4; 67.20 g Na2HPO4.12H2O; 0.50 g NH4Cl; dissolved in Milli-Q water and made up to 1 litre, pH 7.4 ± 0.2
B) 22.50 g MgSO4.7H2O dissolved in Milli-Q water and made up to 1 litre.
C) 36.40 g CaCl2.2H2O dissolved in Milli-Q water and made up to 1 litre.
D) 0.25 g FeCl3.6H2O dissolved in Milli-Q water and made up to 1 litre.

- Test temperature: between 21.7 and 22.2°C.
- pH:
At t=0 d: 7.5
At t=28 d: 7.7 - 8.0
- pH adjusted:no
- Aeration of dilution water: Not before the test, the test is aerated continously
- Suspended solids concentration: The concentration of suspended solids was 3.8 g/l in the concentrated sludge (information obtained from the municipal sewage treatment plant).
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2 litre all-glass brown coloured bottles
- Number of culture flasks/concentration:
Test suspension: containing test substance and inoculum (2 bottles).
Inoculum blank: containing only inoculum (2 bottles)
Positive control: containing reference substance and inoculum (1 bottle).
Toxicity control: containing test substance, reference substance and inoculum (1 bottle).
- Method used to create aerobic conditions:
Synthetic air (a mixture of oxygen (ca. 20%) and nitrogen (ca. 80%)) was sparged through the solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).
- Test performed in open system: yes
- Details of trap for CO2 and volatile organics if used:
CO2 was trapped in barium hydroxide solution. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl (1:20 dilution from 1 M HCl (Titrisol® ampul). Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until the 28th day, for the inoculum blank and test suspension. Titrations for the positive and toxicity control were made at least 14 days.


SAMPLING
- Sampling frequency: Titration were made on day: 2, 5, 7, 9, 14, 19, 23, 27 and 29
- Sampling method: Titration of the whole volume of CO2-absorber

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes
- Other:

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

76

Sampling time:

29 d

Remarks on result:

other: HCl added on the 28th day (last CO2-measurement on the 29th day).

Key result

Parameter:

% degradation (CO2 evolution)

Value:

79

Sampling time:

29 d

Remarks on result:

other: HCl added on the 28th day (last CO2-measurement on the 29th day).

Details on results:

The relative biodegradation values calculated from the measurements performed during the test period revealed 76 and 79% biodegradation of Blown linseed oil, for the duplicate bottles tested. Furthermore, in test bottle A biodegradation of Blown linseed oil of 60% was reached within a 10-day window (10% biodegradation was reached on day 4 and 60% biodegradation was reached on day 14 (nominal days round to integer), the criterion for Ready biodegradability).

In the toxicity control more than 25% biodegradation occurred within 14 days (48%, based on ThCO2). Therefore, the test substance was assumed not to inhibit microbial activity.

Results with reference substance:

The positive control substance was biodegraded by at least 60% (77%) within 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Blown linseed oil was readily biodegradable under the conditions of the modified Sturm test presently performed.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February 10, 1988 - March 31, 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: According to GLP, but not according to a recommended OECD 301 or 302 guideline, and with reporting deficiencies.

Qualifier:

according to guideline

Guideline:

other: EEC, 1984. Method for the determination of ecotoxicity at level 1, Biodegradation; Repetitive Die Away Test. DG XI/400/84. Rev.1

Deviations:

not specified

Remarks:

insufficient information to evaluate compliance

Principles of method if other than guideline:

The test medium is inoculated with activated sludge, stabilized for one week and then spiked with the test substance. After two weeks, three repetitive weekly additions of test substance take place. After each repetitive addition, the water phase is re-aerated to the saturation level. The oxygen consumption is measured weekly up to two weeks after the last addition. The percentage biodegradation is calculated from the measured oxygen consumption and the analytically determined Chemical Oxygen demand (COD).

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Municipal waste water treatment plant of Duiven, The Netherlands, receiving only waste water from domestic origin
- Laboratory culture: no
- Method of cultivation: not relevant
- Storage conditions: no data
- Storage length: preconditioned during a week (unspecified conditions)
- Preparation of inoculum for exposure: no data
- Pretreatment: no data
- Concentration of sludge: final concentration in test flasks 35 mg suspended solids/L.
- Initial cell/biomass concentration: no data
- Water filtered: no data
- Type and size of filter used, if any: no data

Duration of test (contact time):

14 d

Initial conc.:

40 mg/L

Based on:

test mat.

Initial conc.:

ca. 120 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test medium was inoculated with activated sludge (35 mg suspended solids/mL), stabilized for one week and then spiked with the test substance (40 mg/L). The following emulsifiers were used: genapol PF-40, 10% of the weight of the oil; Nonylphenol.10EO.5PO, 20% of the weight of the oil. It was reported that these emulsifiers are not toxic in the biodegradation test and not biodegradable. Control solutions contained inoculums and emulsifier but no test substance. Triplicate flasks (dark glass bottles containing 187 mL of liquid and 93 L of gas space) were used for the treated and the control test solutions. The flasks were incubated at 20°C and were shaken continuously to assure steady state oxygen partitioning between the liquid and the gas phase. After two weeks, three repetitive weekly additions of test substance were performed. After each repetitive addition, the water phase was re-aerated to the saturation level. The oxygen consumption was measured weekly up to two weeks after the last addition. The percentage biodegradation was calculated from the measured oxygen consumption in the treated test solutions, corrected for the oxygen consumption in the control solutions, and the analytically determined Chemical Oxygen Demand (2.15 g/g) of the test substance. A toxicity control was included (sodium acetate in the presence of 40 mg oil/L).

Reference substance:

acetic acid, sodium salt

Remarks:

concentration not reported

Parameter:

% degradation (O2 consumption)

Value:

43

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

37

Sampling time:

21 d

Remarks on result:

other: total % biodegradation for first two additions one week after second addition

Parameter:

% degradation (O2 consumption)

Value:

34

Sampling time:

28 d

Remarks on result:

other: total % biodegradation for first three additions one week after third addition

Parameter:

% degradation (O2 consumption)

Value:

37

Sampling time:

42

Remarks on result:

other: total % biodegradation for four additions two weeks after fourth addition

Details on results:

see below

Results with reference substance:

About 75% biodegradation within one week.

The results are summarised in the table below. These results were derived from mean values for oxygen concentrations in test solutions. The individual replicate values were not reported.   Table 1. Results of Repetitive Die Away test with boiled linseed oil. parameter day 0 day 7 day 14 day 21 day 28 day 35 day 42 total oxygen uptake (mg) - 6.9 8.5 12.0 16.4 20.3 24.1 total oxygen demand (mg) 16.1 16.1 16.1 32.2 48.3 64.4 64.4 % biodegradation - 43 53 37 34 32 37

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

In a test measuring oxygen uptake (not according to any OECD 301 or 302 guideline), 53% biodegradation was recorded after 14 days exposure to non-adapted inoculums, and 37% biodegradation two weeks after the last of three subsequent weekly additions to adapted inoculum. The rate of biodegradation may have been impaired by problems of solubility and mass transfer.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February 10, 1988 - March 31, 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: According to GLP, but not according to a recommended OECD 301 or 302 guideline, and with reporting deficiencies.

Qualifier:

according to guideline

Guideline:

other: EEC, 1984. Method for the determination of ecotoxicity at level 1, Biodegradation; Repetitive Die Away Test. DG XI/400/84. Rev.1

Deviations:

not specified

Remarks:

insufficient information to evaluate compliance

Principles of method if other than guideline:

The test medium is inoculated with activated sludge, stabilized for one week and then spiked with the test substance. After two weeks, three repetitive weekly additions of test substance take place. After each repetitive addition, the water phase is re-aerated to the saturation level. The oxygen consumption is measured weekly up to two weeks after the last addition. The percentage biodegradation is calculated from the measured oxygen consumption and the analytically determined Chemical Oxygen demand (COD).

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Municipal waste water treatment plant of Duiven, The Netherlands, receiving only waste water from domestic origin
- Laboratory culture: no
- Method of cultivation: not relevant
- Storage conditions: no data
- Storage length: preconditioned during a week (unspecified conditions)
- Preparation of inoculum for exposure: no data
- Pretreatment: no data
- Concentration of sludge: final concentration in test flasks 35 mg suspended solids/L.
- Initial cell/biomass concentration: no data
- Water filtered: no data
- Type and size of filter used, if any: no data

Duration of test (contact time):

14 d

Initial conc.:

40 mg/L

Based on:

test mat.

Initial conc.:

ca. 120 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test medium was inoculated with activated sludge (35 mg suspended solids/mL), stabilized for one week and then spiked with the test substance (40 mg/L). The following emulsifiers were used: genapol PF-40, 10% of the weight of the oil; Nonylphenol.10EO.5PO, 20% of the weight of the oil. It was reported that these emulsifiers are not toxic in the biodegradation test and not biodegradable. Control solutions contained inoculums and emulsifier but no test substance. Triplicate flasks (dark glass bottles containing 187 mL of liquid and 93 L of gas space) were used for the treated and the control test solutions. The flasks were incubated at 20°C and were shaken continuously to assure steady state oxygen partitioning between the liquid and the gas phase. After two weeks, three repetitive weekly additions of test substance were performed. After each repetitive addition, the water phase was re-aerated to the saturation level. The oxygen consumption was measured weekly up to two weeks after the last addition. The percentage biodegradation was calculated from the measured oxygen consumption in the treated test solutions, corrected for the oxygen consumption in the control solutions, and the analytically determined Chemical Oxygen Demand (2.04 g/g) of the test substance. A toxicity control was included (sodium acetate in the presence of 40 mg oil/L).

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

35

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

48

Sampling time:

14

Parameter:

% degradation (O2 consumption)

Value:

32

Sampling time:

21

Remarks on result:

other: total % biodegradation for first two additions one week after second addition

Parameter:

% degradation (O2 consumption)

Value:

24

Sampling time:

28

Remarks on result:

other: total % biodegradation for first three additions one week after third addition

Parameter:

% degradation (O2 consumption)

Value:

30

Sampling time:

42

Remarks on result:

other: total % biodegradation for four additions two weeks after fourth addition

Details on results:

see below

Results with reference substance:

About 75% biodegradation within one week.

The results are summarised in the table below. These results were derived from mean values for oxygen concentrations in test solutions. The individual replicate values were not reported.

 

Table 1. Results of Repetitive Die Away test with blown linseed oil, 30 P.

parameter	day 0	day 7	day 14	day 21	day 28	day 35	day 42
total oxygen uptake (mg)	-	5.5	7.6	10.0	14.4	19.1	23.2
total oxygen demand (mg)	15.8	15.8	15.8	31.6	59.4	77.0	77.0
% biodegradation	-	35	48	32	24	25	30

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

In a test measuring oxygen uptake (not according to any OECD 301 or 302 guideline), 48% biodegradation was recorded after 14 days exposure to non-adapted inoculums, and 30% biodegradation two weeks after the last of three subsequent weekly additions to adapted inoculum. The rate of biodegradation may have been impaired by problems of solubility and mass transfer.

Description of key information

Readily biodegradable (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Blown linseed oil was readily biodegradable under the conditions of the conducted modified Sturm test. The 2 other available studies are not conducted according to a recommended OECD 301 or 302 guideline and had deficiencies.