7-methyl-3-methyleneocta-1,6-diene

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:

09 December 2013 - 12 December 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Well conducted and well described study in accordance with GLP and OECD Guideline No 202.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

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)

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Analytical monitoring:

yes

Details on sampling:

Concentrations: single samples for analysis were taken from the control and all test concentrations from replicates without daphnids (except at the end of the test : replicates with daphnids).

Sampling method: samples were taken at the start (t = 0 h) and every 24 h thereafter in old and new solutions and the control.

Storage: samples were analysed directly after sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Method: slow-stirring in a closed vessel with minimum headspace
The test sample formed a clear colourless solution and appeared to be completely soluble and stable when mixed with test water at the concentrations prepared.

Controls: test water without test substance but treated in the same way as the test substance solutions.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
Common name: Daphnia magna (Straus)
Strain: Clone 5
Source: LIEBE - CNRS UMR 7146 - UFR SciFA - Université de Lorraine Campus Bridoux - Bât. IBISE, 8, rue du Général Delestraint - 57070 METZ, bred in the Laboratoires des Pyrénées et des Landes
Age at study initiation: less than 24 h
Method of breeding: parthenogenesis
Feeding during the test: no

ACCLIMATION
Acclimation period: 48 h
Acclimation conditions: same as test
Type and amount of food: mix of 3 algae strains: Chlorella vulgaris = 2.5x10^6 cells/mL/day/daphnid, Desmodesmus subspicatus = 2.5x10^6 cells/mL/day/daphnid and Pseudokirchneriella subcapitata = 5x10^6 cells/mL/day/daphnid
Feeding frequency: daily
Only daphnids not older than 24 hours were used for the test

VALIDITY OF BATCH OF DAPHNIDS
Health during acclimation (any mortality observed): daphnids originated from a healthy stock, showing no signs of stress such as mortality, presence of males, ephippia or discoloured animals.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

not applicable

Hardness:

250 mg/L (CaCO3)

Test temperature:

20°C +/- 2°C

pH:

7.73-7.97 (whole test period)

Dissolved oxygen:

8.21-8.82 mg/L (whole test period)

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 1.0, 1.3, 1.7, 2.3, 3.0 and 4.0 mg/L
Measured concentrations: 0.655, 0.928, 1.161, 1.552, 1.968 and 2.994 mg/L (averaged)

Details on test conditions:

TEST SYSTEM
Test vessel: glass test tubes sealed with screwcaps
Volume: 20 mL (without headspace)
Aeration: no
Renewal rate of test solution: daily
No. of organisms per vessel: 5
No. of vessels per concentration (replicates): 4
No. of vessels per control (replicates): 4
3 abiotic replicates for control and test concentration
Biomass loading rate: 5/20 mL

TEST MEDIUM / WATER PARAMETERS
Source/preparation of dilution water: reconstituted water, as prescribed by OECD Guideline 202
Conductivity: < 10µS/cm
Intervals of water quality measurement: water temperature was recorded continuously throughout the test. Dissolved oxygen concentrations and pH were recorded at the start of the test (t = 0 h), at t = 24 h (new and old solutions) and at the end of the test (t = 48 h) in all vessels.

OTHER TEST CONDITIONS
Adjustment of pH: no
Photoperiod: 16h light and 8h dark

EFFECT PARAMETERS MEASURED
Immobility and abnormal behaviour were determined by visual observation after 24 and 48 h. The daphnids were considered to be immobile if they were not able to swim within 15 seconds after gentle agitation of the test vessels.

TEST CONCENTRATIONS
Spacing factor for test concentrations: 1.3

Range finding study
Test concentrations: 0.1, 1.0 and 2.0 mg/L
Results used to determine the conditions for the definitive study: 70% inhibition was observed at 2.0 mg/L and 100% inhibition was observed at the maximum solubility.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.47 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95%CL: 1.366-1.578

Details on results:

no details

Results with reference substance (positive control):

Results with reference substance are valid.

EC50: 0.98 mg/L

Reported statistics and error estimates:

The software ToxRat® Professional was used for the determination of the effective concentrations. The EC50 value was determined by Probit analysis using linear max. likelihood regression.

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 of MYRCENE on Daphnia magna was 1.47 mg/L, based on mean measured concentrations.

Based on the results of this study, MYRCENE is classified hazardous to the aquatic environment under Regulation (EC) No 1272/2008 (CLP) - Category Acute 1 and Category Chronic 2.

Executive summary:

An acute aquatic toxicity study was performed on Daphnia magna in accordance with GLP and OECD Guideline No 202. Following a preliminary range-finding test, twenty daphnids (four replicates, five daphnids per replicate) were exposed to an aqueous solution of MYRCENE at the required nominal test concentrations of 1.0, 1.3, 1.7, 2.3, 3.0 and 4.0 mg/L. Immobilisation of daphnids was determined in a semi-static 48-h test by visual observation after 24 and 48 h.

The concentrations of the test item were measured at the start (t = 0 h), at t = 24 h (new and old solutions) and at the end of the test (t = 48 h). Concentrations measured in freshly prepared solutions and in 24-h old solutions revealed that the concentrations of the test item were not satisfactorily maintained within ± 20 % of the initial concentrations. Thus, the evaluation of the effects on Daphnia magna was based on the geometric mean of the measured concentrations: 0.655, 0.928, 1.161, 1.552, 1.968 and 2.994 mg/L.

The lowest observed effect concentration based on immobilisation was 1.161 mg/L (measured concentration). At 1.968 mg/L (measured concentration), 100% of daphnids were immobilised. No sublethal effects were reported.

Therefore, the 48h-EC₅₀ of MYRCENE for Daphnia magna was estimated to be 1.47 mg/L, based on mean measured concentrations.

Based on the results of this study, MYRCENE is classified hazardous to the aquatic environment under Regulation (EC) No 1272/2008 (CLP) - Category Acute 1 and Category Chronic 2.

Description of key information

An acute aquatic toxicity study was performed on Daphnia magna in accordance with GLP and OECD Guideline No 202.

Immobilisation of daphnids was determined in a semi-static 48-h test by visual observation after 24 and 48 h.

The evaluation of the effects on Daphnia magna was based on the geometric mean of the measured concentrations: 0.655, 0.928, 1.161, 1.552, 1.968 and 2.994 mg/L.

The lowest observed effect concentration based on immobilisation was 1.161 mg/L (measured concentration). At 1.968 mg/L (measured concentration), 100% of daphnids were immobilised. No sublethal effects were reported.

The 48hr-EC50 was 1.47 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.47 mg/L

Additional information

Key sudy conducted under GLP according to OECD 202 Guideline and EU Method C2.