Cyclopentane, methoxy-

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 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; on this basis the data is considered reliable without restrictions.

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity 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: 10, 22, 46, 100, and 220 mg/L (nominal concentrations)
Test media were prepared daily. Samples were taken from the first and last batches of media, both at the time of preparation (0 hours and 72 hours), and from the expired medium (24 hours and 96 hours).

Vehicle:

no

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: The test substance was directly spiked into diluent water.
Preliminary investigations into the solubility and stability indicated that the test substance was volatile and readily lost from aqueous mixtures. Therefore, each aspirator was sealed with a tightly fitting lid top prevent loss of material.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Length at study initiation (length definition, mean, range and SD): mean = 5.7 cm; S.D. = 0.6 cm
- Weight at study initiation (mean and range, SD): mean = 3.11 g; S.D. = 0.92 g.
- Feeding during test: No

ACCLIMATION
- Acclimation period: From 12 September 2002 (n.b. preliminary test commenced 19 November 2002; main test commenced 13 January 2003)
- Acclimation conditions (same as test or not): Yes
- Type and amount of food: fed to repletion with commercial fry pellets
- Feeding frequency: daily except for the 24 hour period before the test
- Health during acclimation (any mortality observed): Fewer than 1% in the 7 days before the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not applicable

Hardness:

157 mg CaCO3/L

Test temperature:

11 to 15°C

pH:

7.1 to 7.3

Dissolved oxygen:

7.3 - 7.5 mg O2/L

Nominal and measured concentrations:

Nominal: 10, 22, 46, 100, and 220 mg/L
Measured (mean of 4 samples analysed): 11, 23, 49, 103, 220 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass Duran aspirators
- Type (delete if not applicable): Sealed with a tightly fitting lid, and test vessels were completely filled to minimise headspace (to prevent loss of the volatile test material)
- Aeration: No supplementary aeration after the start of the test.
- Renewal rate of test solution (frequency/flow rate): Daily (every 24 hours)
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.95 g/L

OTHER TEST CONDITIONS
- Adjustment of pH: Not required
- Photoperiod: 16 h light / 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Absence of respiratory movement, and absence of response to physical stimulation of the caudal peduncle.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Approximately 2.2
- Range finding study
- Test concentrations:10, 100, and 220 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

Sublethal effects including hyperventilation, increased pigmentation, resting on the base of the vessel, swimming on the top of the vessel, and loss of equilibrium were seen across all test material concentrations including the control level. As these effects were seen in the control level as well as the treated levels, it is thought that they were related to the test conditions employed (specifically the use of sealed vessels) rather than the result of treatment with the test material.
- Mortality of control: One mortality in the control group was observed, however this was within the acceptability criteria for the test guideline.
By the end of the 96-hour exposure period, three fish died in the 46 mg/L level, and one fish died in the 100 mg/L level; as no deaths were recorded in the 220 mg/L level, the deaths were not seen to follow a dose relationship, and the deaths were not considered to be due to treatment with the test material.

Conclusions:

The 96 hour LC50 for NZE to rainbow trout was greater than 220 mg/L.
The "no-observed effect concentration" (NOEC) for NZE in Rainbow trout was 220 mg/L.

Description of key information

Oncorhynchus mykiss, Rainbow trout, LC50 (96 hours) > 220 mg/L.  NOEC = 220 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

220 mg/L

Additional information

A determination of the acute toxicity to fish of the substance was conducted (Huntingdon Life Sciences, 2003). The study was performed in accordance with EC method C1 and OECD test guideline 203, and in compliance with GLP. Groups of 7 rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control group), 10, 22, 46, 100, or 220 mg/L the substance in dechlorinated water for 96 hours.

A number of fish died in two of the treated groups, however this was not attributed to the test material as no deaths were observed in the 220 mg/L level. Sublethal effects were also seen, but these were seen in the control group as well as the treated groups and so the effects were not considered to be related to treatment with the test material.

It was concluded that the 96 -hour LC₅₀ in Rainbow trout was greater than 220 mg/L. The no-observed effect concentration was concluded to be 220 mg/L.