Ozonized olive oil

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date 18 January 2019
Experimental starting date 22 January 2019
Experimental completion date 19 February 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The activated sludge used was sampled from the aeration tank of the ARA Werdhölzli (CH-8048
Zürich), a municipal biological waste water treatment plant on 17 January 2019, 8:30 am.
In accordance with the guideline, this sludge was not pre-adapted to the test item but pre-conditioned to reduce the amount of CO2 produced in the blank controls. In the pre-conditioning procedure, the sludge was washed twice with tap water and once with test medium right after sampling from the waste water treatment plant. After centrifugation, the sludge was suspended in test medium at about 2 g/l dry matter and kept under constant aeration and stirring without feeding for five days until test start.
On the day of test start, this sludge suspension was diluted down to 300 mg/l dry matter, i.e. ten-fold the final concentration, and an appropriate amount of this suspension was added to the flasks (except to the abiotic sterile control).

Duration of test (contact time):

28 d

Initial conc.:

28.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

inorg. C analysis

Details on study design:

The gas-absorption bottles were filled with the 0.13 M KOH solution. The test vessels were connected to the air supply (CO2-free, synthetic) and the gas-absorption bottles were connected to the test vessels, so that the air leaving the individual vessels was passed through the KOH solution and the CO2 produced by mineralisation of the test item trapped therein.
All test vessels were stirred thoroughly and aerated with the aforementioned air supply for the whole test period.
The CO2 trapped in the KOH solutions was determined as inorganic carbon at frequent time intervals to allow for the assessment of the 10-day window for biodegradation in the vessels.
The temperature was measured several times per day with a datalogger.
At the end of the test, the pH and the IC concentration in each test vessel was determined.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (TOC removal)

Value:

68

Sampling time:

28 d

Key result

Parameter:

% degradation (TOC removal)

Value:

41

Sampling time:

10 d

Details on results:

Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) did not reach the pass level of 60% for ready biodegradability in the CO2 Evolution Test within the 10-d window, and therefore, cannot be termed as readily biodegradable. However, the pass level of 60% was reached within 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable, fulfilling specific criteria

Conclusions:

According to OECD guideline 301, a substance is considered "readily biodegradable in the CO2 evolution test" if at least 60% biodegradation, based on IC measurements, is achieved within 10 days after the attainment of 10% biodegradation (10 day-window), and within a total of 28 days.
If the results of the test indicate that the pass level criterion is almost fulfilled (i.e. degradation slightly below 60%) such results can be used to indicate inherent biodegradability. This is also the case when the pass level criterion is fulfilled but the 10-day window criterion is not.
The substance reach thedegradation level of 68% at 28 days and can be considered "inherent biodegradable".

Executive summary:

The biodegradability of Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) exposed to microorganisms derived from the activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions according to the test OECD guideline 301 B.

The biodegradability of Reaction products of olive oil and ozone (NOVOX), based on CO2 evolution and expressed as % of the total organic carbon (TOC) applied, was calculated to be 68% after an incubation time of 28 days.

At the end of the 10-d window, the biodegradation of Reaction products of olive oil and ozone (NOVOX) reached 49%.

Significant biodegradation of the test item was observed after a lag phase of about 4.5 days.

The positive control, sodium benzoate, reached 73% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) did not reach the pass level of 60% for ready biodegradability in the CO2 Evolution Test within the 10-d window, and therefore, cannot be termed readily biodegradable. However, the pass level of 60% was reached within 28 days.

Description of key information

The biodegradability of Reaction products of olive oil and ozone (NOVOX), based on CO2 evolution and expressed as % of the total organic carbon (TOC) applied, was calculated to be 68% after an incubation time of 28 days.
At the end of the 10-d window, the biodegradation of Reaction products of olive oil and ozone (NOVOX) reached 41%.
Significant biodegradation of the test item was observed after a lag phase of about 4.5 days.
The positive control, sodium benzoate, reached 73% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.
Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) did not reach the pass level of 60% for ready biodegradability in the CO2 Evolution Test within the 10-d window, and therefore, cannot be termed as readily biodegradable. However, the pass level of 60% was reached within 28 days.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, fulfilling specific criteria

Type of water:

other: Tap water

Additional information

inherently biodegradable, fulfilling specific criteria