1-methoxy-4-[3-methyl-4-(2-phenylethoxy)but-3-en-1-yl]benzene

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:

25-04-2021 to 08-07-2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study performed under GLP. All relevant validity criteria were met.

Justification for type of information:

Information as to the availability of the in vivo study is provided in 'attached justification'.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Guidelines for the Testing of Chemicals, Effects on Biotic Systems, 203 Fish Acute Toxicity Test, China Environmental Press, China (2013)

Version / remarks:

The test was generally conducted in accordance with or equivalent to the following: (i) China National Standardization Technical Committee for the Management of Hazardous Chemicals. GB/T 27861-2011 Chemicals Fish Acute Toxicity Test [S] (2012). (ii) Chemical Test Guideline stipulations and Chemical Registration Center of MEP. The Guidelines for the Testing of Chemicals, effects on Biotic Systems, 203 Fish Acute toxicity test. Beijing: China Environmental Press and/or 2013 second edition of the aforementioned guideline. (iii) The test was also completed under OECD TG 203: Fish Acute Toxicity Test (2019).

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control) and 100 mg/L nominal (saturated solution of the test item) (limit test)
with equivalent geometric mean measured concentrations of : 0 ( control) and 0.73mg/L
The mean measured concentrations of test item in the old solutions were in the range of 45%-71% of those in the fresh solutions at renewal. Therefore, the effect concentration is based on geometric mean measured concentration(s).
- Sampling method: ca. 50 mL (n=3) extracts from test solution (three replicate samples, one sample pre-treated and stored refrigerated in case of further analysis being required). After sample pre-treatment. Any samples with high concentrations were diluted by dichloromethane to the calibration range before analysis (where applicable: dilution factors, are included in reporting). All pre-treated samples were analysed within 48 hours (with the exception of the spare replicate stored refrigerated, in case required).
- Sample storage conditions before analysis: The samples were analysed immediately (< 24 hours). Following pre-treatment and/or sample preparation. one sample pre-treated and stored refrigerated in case of further analysis being required.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test item was directly weighed into a flask and dissolved with appropriate (10 L) volume test water, to obtain nominal concentrations of 0 (control) and 100 mg/L, forming a saturated solution of test item (limit test). The solution was transferred into a flask and then the suspension was stirred for 2 hours then settled for 20 hours. To avoid insoluble test item inclusion, the middle 5 L layer of test solution was withdrawn and utilised for test exposure. Semi-static exposure procedure was utilise, and the test solution was renewed every 24 hours.
- Eluate: Not applicable.
- Differential loading: Not applicable.
- Controls: A negative/blank control without test item or reference item was also included. A previously conducted sensitivity test with potassium dichromate (positive control/reference item) was included. Full information provided in the full study report.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Not applicable.
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Not applicable.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): In the definitive test there was no evidence of undissolved test item.

Test organisms (species):

other: Gobiocypris rarus

Details on test organisms:

TEST ORGANISM
- Common name: Rare minnow (Gobiocypris rarus)
- Strain: Not reported. Batch generation number C20200815
- Source: Recognised supplier (recorded in full study report) located in China.
- Age at study initiation (mean and range, SD): Not reported.
- Length at study initiation (length definition, mean, range and SD): The length of fish (randomly selected for measurement at test start from all groups) was in the range of 2.0 - 4.0 cm at test initiation : actual 2.7 to 3.1 cm (mean = 2.8 cm and SD = 0.16 cm) ; Body weight (wet weight) 287 to 334 mg (mean = 309 mg and SD = 14 mg). In the treated/control groups the loading was ca. 0.43 g/L (i.e. < 1.0 g fish/litre) based on the above information.
- Method of breeding: Not reported.
- Feeding during test: No.
- Food type: Feeding was conducted during acclimation (daily) until 24-hours prior to test initiation.
- Amount: No feeding during exposure. Not applicable.
- Frequency: No feeding during exposure. Not applicable.

ACCLIMATION
- Acclimation period: 7 days (i.e. > 48 hours)
- Acclimation conditions (same as test or not): Yes. Same water quality, temperature 21 to 25°C and not more than ± 2°C and photoperiod as used during the test (12 hours light; 12 hours dark). Oxygen concentration was in the range of the exposure duration (> 80% air saturation).
- Type and amount of food: Not reported.
- Feeding frequency: Daily; until 24 hours before the start of the test.
- Health during acclimation (any mortality observed): None reported (0% during 7 days pre-test).

FEEDING DURING TEST
- Food type: Not applicable.
- Amount: Not applicable.
- Frequency: Not applicable.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

In accordance with the OECD TG 203 guideline.

Hardness:

160 mg/L expressed as CaCO3 at test start and maintained at 10 - 250 mgCaCO3/L during the test; Test water (dechlorinated water)

Test temperature:

Temperature 22.8 - 23.4 °C during test period, the test was performed in a temperature controlled environment with continuous monitoring and was maintained at 23 ± 2°C.

pH:

Test water (dechlorinated water): pH 6.0 - 8.5 as specified in China Guidelines for the testing of Chemicals 203 test.
The pH was in the range of 7.96 - 8.28 during the study.

Dissolved oxygen:

The test solutions were not aerated during the exposure. The dissolved oxygen concentration in the test solutions during the test was kept at not less than 60 % of the air saturation value. Measured range: 80.5 to 98.2% ASV during the definitive test.
(Note: minimal ASV loss occurred prior to renewal of test solutions ; minimuum measured at any time prior to renewal ASV = 80.6%).

Nominal and measured concentrations:

- Preliminary range-finding test performed on semi-static test system:
0 (control), 1.0 and 5.0 mg/L nominal concentrations.
- Definitive (semi-static test system): 0 (control) and 100 mg/L nominal (saturated solution of the test item) (limit test)
with equivalent geometric mean measured concentrations of : 0 ( control) and 0.73mg/L
The mean measured concentrations of test item in the old solutions were in the range of 45%-71% of those in the fresh solutions at renewal. Therefore, the effect concentration is based on geometric mean measured concentration(s).

Details on test conditions:

TEST SYSTEM
- Test vessel: 5 L glass
- Type (delete if not applicable): glass flask (closed)
- Material, size, headspace, fill volume: glass. ca. 5000 mL fill volume (minimum headspace)
- Aeration: Not continuously aerated although DOC > 60% ASV during exposure.
- Type of flow-through (e.g. peristaltic or proportional diluter): Not reported.
- Renewal rate of test solution (frequency/flow rate): Every 24 hours.
- No. of organisms per vessel: Seven (7) per vessel
- No. of vessels per concentration (replicates): None.
- No. of vessels per control (replicates): One (1)
- No. of vessels per vehicle control (replicates): Not applicable.
- Biomass loading rate: < 1.0 g/L (Actual: ca. 0.43 based on information in the study)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water used in the test (indicated in the full study report).
- Conductivity: Typically, would be: Water: 500±100μs/cm) as specified in China Water quality standard for fisheries in GB-11607-89.
- Culture medium different from test medium: No.
- Intervals of water quality measurement: Every 24 hour intervals; before and/or after renewal as applicable.

OTHER TEST CONDITIONS
- Adjustment of pH: None.
- Photoperiod: 12 hours photoperiod daily
- Light intensity: Not reported.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortalities and abnormalities; measured at 24h, 48h, 72h and 96h as applicable.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Not applicable. Limit test.
- Justification for using less concentrations than requested by guideline: Not applicable. Limit test.
- Range finding study: 0 (control), 100 mg/L nominal concentration (or saturated solution) in semi-static system. 0% mortality was seen and no abnormal/sublethal effects were observed.
- Test concentrations: Definitive Test: 0 (control) and 100 mg/L nominal (saturated solution of the test item) (limit test) in a semi-static system
with equivalent geometric mean measured concentrations of : 0 ( control) and 0.73mg/L
The mean measured concentrations of test item in the old solutions were in the range of 45%-71% of those in the fresh solutions at renewal. Therefore, the effect concentration is based on geometric mean measured concentration(s).
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

yes

Remarks:

Potassium Dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.73 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% C.I.: - mg/L ; based on geometric mean measured concentrations ; > 100 mg/L nominal concentration

Remarks:

i.e. LC50 is above the solubility limit ; no mortality (and/or abnormal observations) below solubility limit

Details on results:

- Behavioural abnormalities: There were no abnormal responses of test fish in the blank control. There were no observed abnormalities in test group at 100 mg/L nominal concentration (saturated solution).
- Observations on body length and weight: Not reported.
- Mortality of control: None.
- Other adverse effects control: None reported.
- Abnormal responses: There were no abnormal responses of test fish in the blank control. There were no observed abnormalities in test group at 100 mg/L nominal concentration (saturated solution).
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Not applicable.
- Effect concentrations exceeding solubility of substance in test medium: Yes. No mortality or other adverse effects were observed in any treatment group at up to the limit of solubility or within the control group.

Results with reference substance (positive control):

- Results with reference substance valid? Yes (previously conducted sensitivity check - documented in the full study report)
- 96h LC50: 164 (C.I. 137 - 197) mg/L ; The 96h-LC50 was within the range of 135.73-416.93 mg/L (referenced in: Zhang et al., Acute toxicity of potassium bichromate and 3,4-dichloroaniline in Chinese rare minnow (Gobiocypris rarus), Acta Laboratorium Animalis Scientia Sinica, (2014), Vol.22, No.2).

Reported statistics and error estimates:

The LC50 values and the 95% confidence limits (LC50) at 72h and 96 h after the start of the test are calculated by Probit Analysis software (US EPA: Probit Analysis Program Version 1.5), as applicable.
However, at the end of exposure, there was no mortality and abnormal signs in the blank control group and/or treatment group at 100 mg/L nominal (saturated solution). Therefore no LC50 needed to be calculated. The LC50 is above the solubility limit ; no mortality (and/or abnormal observations) below solubility limit

Validity criteria fulfilled:

yes

Conclusions:

The 96 hour LC50 for the test item to Rare minnow (Gobiocypris rarus) was determined to be > 0.73 mg/L based on geometric mean measured concentrations and/or > 100 mg/L nominal (saturated solution). No mortality and no adverse effects were observed in the saturated solution of test item (i.e. the 96h-LC50 was found to be greater than the limit of solubility of the test item).

Executive summary:

The acute toxicity of the test item to Rare minnow (Gobiocypris rarus) was determined in a 96 hour semi-static test according to OECD TG 203 and the China CRC MEP guidelines, effects on Biotic Systems, 203 Fish Acute toxicity test (2013) under GLP. Based on the results of preliminary range finding test, the definitive test was conducted as a limit test at: 0 mg/L (control) and 100 mg/L nominal concentration (i.e. a test item saturated solution) and utilising a semi-static system for exposure to seven fish consisting of a single replicate at each test item concentration. One control containing no test item was also performed. The equivalent geometric mean measured concentrations of : 0 (control) and 0.73 mg/L, respectively. The test solution was renewed every 24 hours over a 96 hour period by semi-static renewal exposure. The test was performed under 12 hour photoperiod at 22.8 - 23.4°C (23°C ; constant to within 2°C) and pH 7.96 - 8.28. Dissolved oxygen was no less than 60% of ASV (actual: 80.5 to 98.2%). No feeding was conducted during the exposure. Concentrations of test item were determined at the start (t=0h), 24h, 48h, 72h renewals and at end (t=96h) by GC-FID analysis. Behavioural abnormalities and biological effects were reported during the course of the study, where applicable. At the end of exposure, there was no mortality and abnormal symptoms in the blank control group and treatment group. The mean measured concentrations of test item in the old solutions were in the range of 45%-71% of those in the fresh solutions at renewal. Therefore, the effect concentration is based on geometric mean measured concentration(s). Under the conditions of this study, the 96 hour LC50 was determined to be > 0.73 mg/L based on geometric mean measured concentrations and/or > 100 mg/L nominal (saturated solution). No mortality and no adverse effects were observed in the saturated solution of test item. The 96h-LC50 was found to be greater than the limit of solubility of the test item.

Description of key information

LC50 (fish) = > 0.73 mg/L based on geometric mean measured concentrations or > 100 mg/L based on nominal loading concentration, the 96h-LC50 was found to be greater than the limit of solubility of the test item, 96-hour, freshwater, OECD TG 203, 2021

Additional information

Key study : OECD TG 203, 2021 : The acute toxicity of the test item to Rare minnow (Gobiocypris rarus) was determined in a 96 hour semi-static test according to OECD TG 203 and the China CRC MEP guidelines, effects on Biotic Systems, 203 Fish Acute toxicity test (2013) under GLP. Based on the results of preliminary range finding test, the definitive test was conducted as a limit test at: 0 mg/L (control) and 100 mg/L nominal concentration (i.e. a test item saturated solution) and utilising a semi-static system for exposure to seven fish consisting of a single replicate at each test item concentration. One control containing no test item was also performed. The equivalent geometric mean measured concentrations of : 0 (control) and 0.73 mg/L, respectively. The test solution was renewed every 24 hours over a 96 hour period by semi-static renewal exposure. The test was performed under 12 hour photoperiod at 22.8 - 23.4°C (23°C ; constant to within 2°C) and pH 7.96 - 8.28. Dissolved oxygen was no less than 60% of ASV (actual: 80.5 to 98.2%). No feeding was conducted during the exposure. Concentrations of test item were determined at the start (t=0h), 24h, 48h, 72h renewals and at end (t=96h) by GC-FID analysis. Behavioural abnormalities and biological effects were reported during the course of the study, where applicable. At the end of exposure, there was no mortality and abnormal symptoms in the blank control group and treatment group. The mean measured concentrations of test item in the old solutions were in the range of 45%-71% of those in the fresh solutions at renewal. Therefore, the effect concentration is based on geometric mean measured concentration(s). Under the conditions of this study, the 96 hour LC50 was determined to be > 0.73 mg/L based on geometric mean measured concentrations and/or > 100 mg/L nominal (saturated solution). No mortality and no adverse effects were observed in the saturated solution of test item. The 96h-LC50 was found to be greater than the limit of solubility of the test item.