1-Butoxy-4-[4-(trans-4-ethylcyclohexyl)-1-cyclohexen-1-yl]-2,3-difluorobenzene

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:

Aug 17, 2015 - Dec 04, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted for a registration in a non-EU country.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Remarks:

Guidelines of Good Laborato,y Practices on Chemical Testing (HJIT 155-2004, MEP, China)

Specific details on test material used for the study:

Preliminary test showed that there was no mortality observed in the saturated solution with the nominal concentration of 10 mg/L filtrated with a 0.22 μm membrane filter within the test period of 96 hours.

Analytical monitoring:

yes

Details on sampling:

The concentrations of test solutions were measured at the start and end of the exposure, before and after each renewal. 100 mL sample was taken from treated groups and injected to analyze concentration
after pretreatment.

Details on test solutions:

According to the stability test, test substance is stable in test water (the measured concentration of test substance was within 80%~120% of the nominal concentration after 24 hours). The test fish were exposed in the test solution under the semi-static system with test solution renewed every 24 hours.

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Semi-static exposure method was performed in the preliminary test. Preliminary test showed that there was no mortality observed in the saturated solution with the nominal concentration of 10 mg/L filtrated with a 0.22 μm membrane filter within the test period of 96 hours. The concentration of saturated solution is less than 2 mg/L according to the concentration analysis in the preliminary test.
According to the preliminary test, one treated group of saturated solution (with the nominal concentration of 2 mg/L which were filtrated by polytetrafluoroethylene microfiltration membrane with 0.22 μm pore size, OECD SERIES ON TESTING AND ASSESSMENT Number 23) and blank group were designed in the definitive test. Each group contained ten fish without replicate. Test solution volume was 5 L.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Strain: AB
- Source: Suzhou Weimei Aquarium
- Generation: FZA000-20150617-03
- Sensitivity: LC50(24 h) of potassium dichromate was 202.683 mg/L

ACCLIMATION
- Acclimation period: The fish had been taken from the flowing water breeding system (which is a part of the testing facility) followed by a 8-day acclimatization period in the semi-static test system.
During the acclimatization period, light was set as 14 hours photoperiod daily. Temperature, pH and dissolved oxygen concentration of water were daily measured and recorded, results are shown in
section 5.1.4. Fish were fed daily until 24 hours before the test was started. Fish not selected for testing were returned to fish breeding system.

- Acclimation conditions (same as test or not): yes
- Type and amount of food during acclimation: Fairy shrimp eggs were purchased from Tianjin. The eggs were hatched to larva as the food for fish.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

55 mg/L (CaCO3)

Test temperature:

23.1-23.4 °C

pH:

7.37-7.76

Dissolved oxygen:

81.5 ~ 101.2 %

Nominal and measured concentrations:

2 mg/L (nominal)

The test solutions were prepared in fish breeding water as follows then analyzed via UPLC. The recovery of RELI~REL3 were 97.59%-108.29%, and RSD=S.20%; the recovery of REH1~REH3 were in the range of 89.83%-108.29%, and RSD=7.87%. The results met the criteria for recovery, i.e., between 80%~ 110% of nominal concentration with RSD less than 20%.


The measured concentrations before renewal within 70.7%~88.1 % of the initial concentration, which could not be satisfactorily maintained within 80-120% of measured initial concentration throughout the test.

Details on test conditions:

TEST SYSTEM
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.598 g fish/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water

OTHER TEST CONDITIONS
- Photoperiod: 14 h light/10 h dark


EFFECT PARAMETERS MEASURED:
mortality, inactivity, abnormal swimming pattern, other abnormal behaviour recorded at 3, 6, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1 mg/L (nominal)

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 2 mg/L

Nominal / measured:

nominal

Conc. based on:

other: accomodated fraction (WAF)

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality (fish)

Remarks on result:

other: value based on measured concentration

Results with reference substance (positive control):

24h-LC50: 202.683 mg/L (potassium dichromate)

Validity criteria fulfilled:

yes

Conclusions:

In this study no toxic effects were observed up to the saturated concentration within 96 h. Therefore, the LC50 is determined to be >2 mg/L (nominal) corresponding to 0.0003245 mg/L (measured concentration).

Executive summary:

Objective

To evaluate the short-term toxicity effects of the test substance on zebra-fish species with the determination of a 96hr LC50 in a semi-static aquatic system.

Methods

According to the results of the preliminary test, one treatment group with the nominal concentration of 1 mg/L and blank group (fish breeding water) are designed in the definitive test. Each group contained ten fish without replicate. The duration of the test was 96 hours. The test fish were exposed in closed bottles filled with the test solution under the semi-static conditions with test solution renewed every 24 hours. Testing was performed under the conditions of 14 hours photoperiod daily, 23.1~23.4 °C water temperature, pH of 7.37~ 7. 76, 81.5%~ 101.2% air saturation value of dissolved oxygen concentration and without feeding. The fish were observed at 3, 6, 24, 48, 72 and 96 hours after the start of the exposure. The concentrations of the test substance were measured at the start and end of the exposure, before and after each renewal with HPLC analysis.

Results

At the end of the test, the cumulative mortalities were 0% and visible abnormalities were not found in the blank group and treated group .The measured concentrations before renewal within 70.7%~88.1 % of the initial concentration, which could not be satisfactorily maintained within 80-120% of measured initial concentration throughout the test. Therefore, LC50 values were estimated based on the time weighted average (TWA) of measured concentrations. TWA of measured concentration during test period of 96 hours was 0.0003245 mg/L in the treated group. The LC50 (96h) value of the test material on Zebrafish species was greater than 0.0003245 mg/L based on measured concentration

(TWA).

Conclusion

In this study no toxic effects were observed up to the saturated concentration within 96 h. Therefore, the LC50 is determined to be >2 mg/L (nominal) corresponding to 0.0003245 mg/L (measured concentration).

Description of key information

OECD 203: LC50 (96 h) > 2 mg/L (nominal); no mortality was observed up to the saturated concentration