Eugenol

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:

from 22 June to 24 June 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study in compliance with international recognised guidelines, only reference to SOP available for analytical methods used.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

To produce the stock solution (10 mg/L), the test substance was weighted into water, treated for 60 seconds at 8000 rpm. with an ultra-turrax and after-wards stirred for 1 hour on a magnetic stirrer.
Separation of test animals according to size before start of test.

Vehicle:

no

Details on test solutions:

See details on sampling.
Test concentrations [mg/L]: 0.2, 0.4, 0.8, 1.6, 3.2, 6.4

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna STRAUS, parthenogenetic females
Origin of species: cloned at the Federal Health Office (BGA) in Berlin
Age of test animals : 0 - 24 hours
Keeping water: M4-Medium according to Elendt and BGA (1992)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

not applicable

Hardness:

15.3 [°dH]

Test temperature:

19.3ºC

pH:

8.1

Dissolved oxygen:

8.7 - 9.0 mg/L

Salinity:

no data

Nominal and measured concentrations:

results by start of test and after 48 hours [mg/L]
nominal concentration test substance [mg/L] 0 hours 48 hours
control <0.03 <0.03
0.2 0.2 0.14
0.4 0.41 0.31
0.8 0.82 0.7
1.6 1.55 1.45
3.2 3.16 2.99
6.4 5.71 5.79

Details on test conditions:

Operating conditions : Static system in accordance with above study method.
Photoperiod : 16 hours light / 8 hours dark
Test procedure:
-cylindrical test vessels diameter 4.0 cm, height 6.5 cm
- 20 ml test medium
- not ventilated
Method of administration : stock solution (10 mg/L)
Control : M4-Medium according to Elerndt and BGA (1992)
Water for dilution : M4-Medium according to Elendt and BGA (1992)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.36 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

3.08 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.05 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: geometric mean: EC0/EC100

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.973-1.315 mg/L

Details on results:

After 48 hours:
EC 0: 0.36 mg/L
EC 100: 3.08 mg/L

Geometric mean:
EC0/EC100: 1.05 mg/L

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The EC0 and EC100 are determined directly from the study, while the EC50 (measured) is calculated as the geometric mean of the EC0 and EC100 values.

The 48h-EC50 (nominal) value was calculated with ToxRat to be 1.13 mg/L (95% CL: 0.973 - 1.315 mg/L).

	Immobile daphnids
Nominal concentration test substance [mg/l]	24h	48h	24h	48h	Oxygen [mg/ml] 48h	pH 48h	Temperature [°C] 48h
control	0	0	0 %	0 %	9	8.1	19.3
0.2	0	0	0 %	0 %	9	8.1	19.3
0.4	0	0	0 %	0 %	8.8	8.1	19.3
0.8	0	0	0 %	0 %	8.8	8.1	19.3
1.6	7	19	35 %	95 %	8.7	8.1	19.3
3.2	8	20	40 %	100 %	8.8	8.1	19.3
6.4	12	20	60 %	100 %	8.8	8.1	19.3

No. Parallel solutions: 2

Test volume: 20 ml

No. daphnids per vessel: 10

The values of the abiotic parameters (oxygen, pH and temperature) were determined from the total volume of the parallel solutions.

Validity criteria fulfilled:

yes

Conclusions:

The estimated EC50 value based on the geometric mean of the EC0 and EC100 is not relevant. The EC50 value was recalculated using standard statistical method and determined to be 1.13 mg/L.

Executive summary:

Short-term toxicity to aquatic invertebrates Daphnia magna was assessed according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), and EU Method C.2 (Acute Toxicity for Daphnia) and in compliance with GLP. Daphnia were exposed under static conditions to the substance at concentrations of 0.2, 0.4, 0.8, 1.6, 3.2, 6.4 mg/L in freshwater.

The test was performed with 10 daphnia per vessel. For each concentration, the percentage of immobilisation at 24 hours and 48 hours was recorded, and test concentrations were confirmed by HPLC analysis.

After 48 hours EC0 was 0.36 mg/L and EC100 3.08 mg/L (measured values), and the EC50 was 1.13 mg/L (nominal).

Description of key information

OECD guideline 202, GLP, key study, validity 1 
48h-EC50 = 1.13 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

1.13 mg/L

Additional information

One acute toxicity study was performed to assess the acute toxicity of eugenol to Daphnia magna (Bayer, 1999). The study was conducted under GLP and according to OECD Guideline 202. The study was conducted in a static system. Daphnia were exposed to the substance at a range of concentrations from 0.2 to 6.4 mg/L in freshwater. For each concentration, the percentage of immobility at 24 and 48 hours was recorded. Based on data obtained with Bayer (1999) study, CEHTRA (2013) determined that the estimated EC50 value based on the geometric mean of the EC0 and EC100 is not relevant. The EC50 value was recalculated using standard statistical method to be 48h-EC50 = 1.13 mg/L (95% CL: 0.973 - 1.315 mg/L), based on nominal concentrations. This value should be used for classification and risk assessment purposes.