Caryophyllene

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:

16 April 2002 to 18 April 2002

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:

1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All concentrations and control
- Sampling method: Samples were taken after 0 h (new media) and 48 h (old media)
- Sample storage conditions before analysis: Samples were stored at 7 ± 2°C until the start of analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Three stock solutions with a nominal concentration of 100 mg/L were prepared with dilution water one day prior to application. The stock solutions were shaken with 20 upm for 24 h. Undissolved particles of the test item were removed by centrifugation at 3000 rpm for 20 minutes. After centrifugation the three stock solutions were mixed together.
- Controls: Dilution water only
- Evidence of undissolved material: Undissolved particles were removed by centrifugation.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: STRAUS (Clone 5)
- Age at test start: 2 to 24 h old
- Feeding during test: Not reported
- Feeding during culturing:
- Food type: Mix of Desmodesmus subspicatus and Chlorella vulgaris
- Amount: > 10E6 cells/mL
- Frequency: 5 times weekly

ACCLIMATION
- Acclimation period: 2 h in dilution water
- Acclimation conditions: Same as test

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: 2 to 24 h old daphnids for the test were obtained by removing the mother animals twice within 22 h.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

254 mg CaCO3/L

Test temperature:

20 ± 1°C

pH:

0 h: 7.85 to 8.25
48 h: 7.69 to 7.93

Dissolved oxygen:

0 h: 8.57 to 8.75 mg/L
48 h: 7.92 to 8.42 mg/L

Conductivity:

688 µS/cm

Nominal and measured concentrations:

Dilutions of saturated solution: 1:16, 1:8, 1:4, 1:2 and 1:1
mean measured concentrations: 0.011, 0.021, 0.043, 0.085 and 0.17 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers (5 cm inner diameter, 8 cm height)
- Type: Open
- Material, size, headspace, fill volume: Filled with 20 mL dilution water
- Aeration: None reported
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: According to EEC 92/69 L383A C.2
- Culture medium different from test medium: Yes, culture medium was Elendt M4, modified to a total hardness of 160 to 180 mg CaCO3/L
- Intervals of water quality measurement: pH and oxygen concentration were measured in one additional replicate per concentration and control group at the beginning of the test and in the old media in all replicates after 48 hours. The pH, dissolved oxygen concentration, conductivity, total hardness and temperature of the dilution water was determined prior to test start. The room temperature was recorded throughout the test.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 h light/dark cycle
- Light intensity: Diffuse light, 1200 lux maximum

EFFECT PARAMETERS MEASURED: Immobilisation was observed after 24 and 48 hours of exposure.

RANGE-FINDING STUDY
- Test concentrations: 1:100, 1:10 and 1:1 dilutions of the test item
- Results used to determine the conditions for the definitive study: Yes, definitive test item concentrations ranged from 1:16 to 1:1 of the test item

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.17 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: saturated concentration

Details on results:

- Mortality of control: No mortalities were observed in the control.
- Effect concentrations exceeding solubility of substance in test medium: The test item was clearly dissolved in all dilution levels of the saturated solution throughout exposure.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50 value should be within 1.0 to 2.5 mg/L according to AQS: DIN Guideline 38412 L 30
- Limit test: No
- Dose-response test: Yes, test concentrations 0.58, 1.0, 1.8, 3.2 and 5.8 mg/L
- ECx: EC10 = 1.5 mg/L, EC50 = 2.1 mg/L (95% confidence interval 1.8 to 2.3 mg/L), EC100 = 5.8 mg/L at 24 hours

Reported statistics and error estimates:

The EC10, EC50 and EC100 values for the test item could not be determined.

Table 1. Immobility results

Mean measured test concentrations (mg test item/L)	Mean % immobilisation at 24 h	Mean % immobilisation at 48 h
Control	0	0
0.011	0	0
0.021	0	0
0.043	0	0
0.085	0	0
0.17	0	5

Validity criteria fulfilled:

yes

Remarks:

No control Daphnia were immobilised or trapped on the water surface, the oxygen concentrations, pH values and the results for the reference substance were acceptable, and the real concentrations were calculated from mean measured concentrations.

Conclusions:

The 48-hour EC50 was >0.17 mg/L.

Executive summary:

The test item toxicity to Daphnia magna was determined in a 48 -hour static test. Daphnia were exposed to dilutions of a saturated test item solution, corresponding to mean measured concentrations of 0.011, 0.021, 0.043, 0.085 and 0.17 mg test item/L, alongside a dilution water control. The 48-hour EC50 was >0.17 mg/L. This study is reliable without restriction (Klimisch 1) as it was GLP-compliant and was conducted according to OECD TG 202 and EU Method C.2.

Description of key information

The 48-hour EC50 was >0.17 mg/L (saturated solution). There was no acute toxicity up to the limit of solubility.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.17 mg/L

Additional information

The test item toxicity to Daphnia magna was determined in a 48 -hour static test (2002). Daphnia were exposed to dilutions of a saturated test item solution, corresponding to mean measured concentrations of 0.011, 0.021, 0.043, 0.085 and 0.17 mg test item/L, alongside a dilution water control. The 48-hour EC50 was >0.17 mg/L. No acute toxicity was observed up to the limit of solubility. This study is reliable without restriction (Klimisch 1) as it was GLP-compliant and was conducted according to OECD TG 202 and EU Method C.2.