Cyclopentane, methoxy-

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:

27 November 2002 - 18 January 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD and EC test guidelines and in compliance with GLP, so the data is considered reliable without restrictions.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

92/69/EEC, C2

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Analytical purity: 99.9%
- Lot/batch No.: 020618

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All concentrations (nominally 10, 22, 46, 100, and 220 mg/L).
- Sampling method: Duplicate 30 mL samples taken from each test concentration and control at 0 hours (main stock solutions) and after 48 hours (replicates pooled).

Vehicle:

no

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: The test substance was directly spiked into Elendt M4 medium.

Preliminary investigations into the solubility and stability of the test substance indicated that it was volatile and readily lost from aqueous mixtures. Therefore, following the addition of the Daphnia, each test vessel was sealed with a screw-capped lid to prevent loss of material.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Straus
- Age at study initiation (mean and range, SD): Less than 24 hours old
- Method of breeding: Parthenogenesis
- Feeding during test
- Food type: Chlorella vulgaris
- Frequency: daily (during test organism culture; no suplementary feeding was given during the study period)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 to 21°C

pH:

7.6 - 7.9

Dissolved oxygen:

8.3 - 8.6 mg O2/L

Nominal and measured concentrations:

Nominal: 0, 10, 22, 46, 100, and 220 mg/L
Measured: 0 (no test item detected), 9.7, 20, 46, 100, 213 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass jars
- Type (delete if not applicable): closed (sealed to prevent loss of the volatile test material)
- Material, size, headspace, fill volume: 250 mL capacity / 250 mL fill volume.
- Aeration: No supplementary aeration during the test period
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 50 mL test solution per organism

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hours light / 8 hours dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilisation; Daphnia were considered to be immobile if they were unable to swim within approximately 15 seconds following gentle agitation of the test vessel.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Approximately 2.2
- Range finding study
- Test concentrations: 1.0, 10, 100, and 1000 mg/L
- Results used to determine the conditions for the definitive study: Yes. Preliminary study indicated that the EC50 was likely to lie between 10 and 100 mg/L.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

76 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 62 - 88 mg/L (95% CL)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

35 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 27 - 40 mg/L (95% CL)

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

100 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

20 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: No Daphnia were immobilised in the control group

Conclusions:

The 48 hour EC50 (immobilisation) value for NZE with Daphnia magna was determined to be 35 mg/L.
The 'No-observed effect concentration' (NOEC) was 20 mg/L.

Description of key information

Daphnia Magna, EC50 (48 hours, immobilisation) = 35 mg/L

NOEC (48 hours) = 20 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

35 mg/L

Additional information

A determination of the acute toxicity to aquatic invertebrates of the substance was conducted (Huntingdon Life Sciences, 2003). The study was performed in accordance with EC method C2 and OECD test guideline 202, and in compliance with GLP. Groups of 20 Daphnia magna were exposed to 0 (control group), 10, 22, 46, 100, or 220 mg/L the substance in Elendt M4 Culture medium.

After 24 hours' exposure, all of the Daphnia in the 220 mg/L group, and 95% of the Daphnia in the 100 mg/L group were immobilised but no Daphnia in other groups were immobilised. After 48 hours, all of the Daphnia in the 100 mg/L group and 95% of the Daphnia in the 46 mg/L group were immobilised, but none of the Daphnia in the lower concentration groups were immobilised. The EC₅₀ value and NOEC were expressed in terms of the mean measured concentration of the substance (mean of measurements at 0 hours and 48 hours).

It was concluded that the 48 -hour EC₅₀ in Daphnia Magna was 35 mg/L. The no-observed effect concentration was concluded to be 20 mg/L.