Ozonized olive oil

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date 7 March 2019
Experimental starting date 8 March 2019
Experimental completion date 14 March 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Test, adopted April 2004.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The concentrations of Reaction products of olive oil and ozone (NOVOX) in the test media were analysed by DOC analytics at the beginning and after 24 and 48 hours of exposure. The DOC determinations confirmed the very poor solubility of the test item. Conclusions about its stability cannot be drawn, since this type of analytics is non-specific. Therefore, the effective concentrations ECx were assessed based on the loading rate of the test item, which was 100 mg/l.

Vehicle:

yes

Details on test solutions:

The test item Reaction products of olive oil and ozone (NOVOX) is a solid and poorly soluble UVCB substance.
The test solution consisted of the Water Soluble Fraction, prepared by addition of a stock solution of test item in hexane to glassware, evaporation of the hexane, addition of test water, stirring for 96 hours and finally filtration.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus was supplied by IES Ltd., 4108 Witterswil, Switzerland. The daphnids are cultivated at Arcadis in reconstituted water using temperature and light conditions identical
to those of the test and are fed with a suspension of Desmodesmus subspicatus in reconstituted water with an optical density at 680 nm of about 12 units. This results in a final concentration of about 0.1 units from Monday to Thursday and 0.4 units on Fridays in the culture vessel.

RECONSTRUITED WATER
Reconstituted water (Elendt M4 medium) prepared according to the test guidelines was used for daphnia cultivation and testing. Analytical grade salts were dissolved in ultra-pure water.
The proportion Ca:Mg ions is 4:1 and Na:K ions 10:1.
Hardness: 2.5 mM (based on the sum of Ca2+ and Mg2+), Carbonate Alkalinity: 0.8 mM
The reconstituted water used contained an oxygen concentration of ≥3 mg O2/l. The pH was adjusted to 7.5±0.2. The conductivity was 645 μS/cm.

Test type:

static

Water media type:

other: Reconstituted water (Elendt M4 medium) prepared according to the test guidelines was used for daphnia cultivation and testing. Analytical grade salts were dissolved in ultra-pure water

Total exposure duration:

48 h

Hardness:

Hardness: 2.5 mM (based on the sum of Ca2+ and Mg2+), Carbonate Alkalinity: 0.8 mM

Test temperature:

18–22 °C, controlled at ±1 °C.

pH:

The pH of reconstituted water used was adjusted to 7.5±0.2.
The pH should not vary by more than 1.5 units during the exposure.

Dissolved oxygen:

Minimum dissolved oxygen concentration in test medium at 0h [mg O2/l]=6.1
Minimum dissolved oxygen concentration in control at 0h [mg O2/l]=7.4
Minimum dissolved oxygen concentration in test medium at 48h [mg O2/l]=8.5
Minimum dissolved oxygen concentration in control at 0h [mg O2/l]=8.8

Conductivity:

The conductivity was 645 μS/cm.

Nominal and measured concentrations:

1, 10, 100 mg/L

Details on test conditions:

Test vessel 100 ml glass beaker containing 50 ml of test medium, covered with a glass plate to avoid evaporation and contamination of the test solutions with dust.
Number of Daphnia: 20 individuals per test concentration and for the control divided in four groups of five individuals.
Age: Less than 24 hours.
Light: 16 hours photoperiod per day, about 550–1100 lux, source: overhead white fluorescent tubes.
Temperature: 18–22 °C, controlled at ±1 °C.
pH: The pH should not vary by more than 1.5 units during the exposure.
Feed: The daphnias are not fed during the test.
Test design: Static exposure conditions.
Test duration: 48 hours.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

During the first 24 hours of the test, no immobilised test organisms were determined in the control and in the single loading rate of 100 mg/l. Thus, the 24-hour EC50 was greater than 100 mg/l loading rate.
The no observed effect concentration (NOEC) after 24 hours was determined to be 100 mg/l.
After 48 hours of exposure, no immobilised test organisms were determined in the control and the single loading rate of 100 mg/l. Thus, the 48-hour EC50 was greater than 100 mg/l loading rate.
The no observed effect concentration (NOEC) after 48 hours was determined to be 100 mg/l.
No signs of disease or stress were observed in any control or test solution.
No remarkable observations were made concerning the appearance of the test media.

Validity criteria fulfilled:

yes

Conclusions:

Test concentrations
The concentrations of Reaction products of olive oil and ozone (NOVOX) in the test media were
determined by DOC analysis at the beginning and after 24 and 48 hours of exposure and confirm the very poor solubility of the test item: only 2.1 mg/l test item were measured at the beginning of the test. Conclusions about its stability cannot be drawn, since this type of analytics is non-specific. Therefore, the effective concentrations ECx were assessed based on the loading rate of the test item, which was 100 mg/l.

Immobilisation
During the first 24 hours of the test, no immobilised test organisms were determined in the control and in the single loading rate of 100 mg/l. Thus, the 24-hour EC50 was greater than 100 mg/l loading rate.
The no observed effect concentration (NOEC) after 24 hours was determined to be 100 mg/l.
After 48 hours of exposure, no immobilised test organisms were determined in the control and the single loading rate of 100 mg/l (Table 4). Thus, the 48-hour EC50 was greater than 100 mg/l loading rate.
The no observed effect concentration (NOEC) after 48 hours was determined to be 100 mg/l.

Observations and environmental conditions
No signs of disease or stress were observed in any control or test solution.
No remarkable observations were made concerning the appearance of the test media.
The pH value in the control replicates changed by 0.1 units. The temperature ranged from 19 to 20 °C. The O2 concentration varied between 6.1 and 8.8 mg/l.

Description of key information

The acute toxicity of Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) to Daphnia magna was investigated according to the OECD guideline 202 under static exposure conditions over a period of 48 hours.

The test item Reaction products of olive oil and ozone (NOVOX) is a solid and poorly soluble UVCB substance.

The test solution consisted of the Water Soluble Fraction, prepared by addition of a stock solution of test item in hexane to glassware, evaporation of the hexane, addition of test water, stirring for 96 hours and finally filtration.

The single loading rate tested was 100 mg/l. Four replicates for the test concentration as well as for the control, were tested.

The concentrations of Reaction products of olive oil and ozone (NOVOX) in the test media were analysed by DOC analytics at the beginning and after 24 and 48 hours of exposure. The DOC determinations confirmed the very poor solubility of the test item. Conclusions about its stability cannot be drawn, since this type of analytics is non-specific. Therefore, the effective concentrations ECx were assessed based on the loading rate of the test item, which was 100 mg/l.

In the control and at the test concentration of 100 mg/l, no significant number (≤10% immobilisation) of immobilised test organisms was observed during the test period of 48 hours.

The biological test results of Reaction products of olive oil and ozone (NOVOX) to Daphnia magna after 24 and 48 hours of exposure are summarized in the following table based on the loading rate of the test item:

Parameter	Immobilisation (0-24 h)[mg/l]	Immobilisation (0-48 h)[mg/l]
EC50	>100	>100
NOEC	100	100

In conclusion, Reaction products of olive oil and ozone (NOVOX) (EC no. 919–979–9) had no acute toxic effects on Daphnia magna up to its solubility limit in test water under the conditions of the test.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

EC50>100mg/l

NOEC=100mg/l