4''-Butoxy-4-ethyl-2',2'',3''-trifluoro-[1,1':4',1'']-terphenyl

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:

Mar 03, 2014 - Oct 08, 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Principles of method if other than guideline:

none

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Dechlorinated drinking water (Shanghai Shinan Drinking Water Ltd.) sterilized by UV lamp is used in the test. Waters with total hardness of 145 mg CaCO3 per liter and of a pH between 6 and 8 were used.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The test organism, Danio rerio which was bred in our laboratory. Aclimatisation was perfomerd for more than 14 days under test conditions. During holding and acclimatization until one day before the start of the test the fish were fed with a commercial fish diet (Brine Shrimp Aquarium Flake Food). During holding and acclimatization no fish died in the test fish batch and all fish were healthy.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

about 145 mg CaCO3

Test temperature:

22.2 - 23.9 °C

pH:

6.77 to 7.09

Dissolved oxygen:

69.5 - 89 %

Nominal and measured concentrations:

loading rate of 100 mg/L (mean measured concentration < LOD2, LOD2=20.4 ng/L)

Details on test conditions:

none

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 20.4 ng/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

A limit test was performed in accordance with the result of the preliminary test to demonstrate that the test substance at the loading rate of 100mg/L has no acute toxicity effect on the test Brachydanio rerio.

In the controls and the treatments at the loading rate of 100mg/L (mean measured concentration <20.4 ng/L) no fish death was determined during the limit test period of 96 hours. Therefore, the 96h-NOEC and the 96h-LC50 of the test substance to zebra fish were determined to be the loading rate of 100 mg/L (mean measured concentration <20.4 ng/L). The 96h-LOEC, the 96h-LC50 and 96h-LC100 were clearly higher than the loading rate of 100 mg/L (mean measured concentration <20.4 ng/L).

The pH values in the treatments and the controls ranged from 6.77 to 7.09, and water temperature was maintained at abut 23 °C. During the period of the test, the dissolved oxygen concentration was between 69 and 89% , which fulfilled the criteria for a valid test.

Results with reference substance (positive control):

The sensitivity of the Brachydanio rerio and conformity with the procedure were supported by the result of the reference substance, potassium dichromate. The 24h-LC50 of the potassium dichromate was calculated as 348 mg/L which fulfilled the criteria for a valid test that the 24h-LC50 of the potassium dichromate should range 200 mg/L to 400 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

Based on these results and the acute toxicity grading criteria in the Guidelines for the Hazard Evaluation of New Chemical Substances (HJ/T 154-2004), the test substance has no acute toxicity effect on zebra fish under the present conditions of the test.

Executive summary:

 

The acute toxicity effect of the test substance to zebra fish (Brachydanio rerio) was determined in a 96-hour static test with a daily test medium renewal. A limit test was performed in accordance with the result of the preliminary test to demonstrate that the test substance at a loading rate of 100 mg/L has no acute toxicity effect on the test organisms. Thus, only the treatments at a loading rate of 100 mg/L and the controls were tested.

 

Due to the low water solubility of the test substance and shortage of appropriate auxiliary solvents or dispersants, a supersaturated dispersion of the test substance with a loading rate of 100 mg/L was homogenized by continuously stirred over 4 hours prior to each test medium preparation. Then the dispersion was filtered with the 0.45 µm membrane filter. Only the undiluted filtrate with the maximum concentration of dissolved test substance was used as the test medium.

 

The analytically measured test substance concentrations in the analyzed test medium samples were <0.06 mg/L at both the beginning and the end of the test respectively. The biological results are related to the treatments of 100 mg/L and to the mean measured test substance concentration of <0.06 mg/L (calculated as the average of the test concentration).

 

In the controls and the treatments at the loading rate of 100 mg/L (mean measured concentration <0.06 mg/L) no fish death was determined during the limit test period of 96 hours. Therefore, the 96h-NOEC and the 96h-LC₅₀of the test substance to zebra fish were determined to be the loading rate of 100 mg/L (mean measured concentration <20.4 ng/L). The 96h-LOEC, the 96h-LC50 and 96h-LCroo were clearly higher than the loading rate of 100 mg/L (mean measured concentration <20.4 ng/L).

 

In conclusion, the test substance had no acute toxic effects on zebra fish under the present conditions of the test.

Description of key information

NOEC (96 h) =100 mg/L (nominal)

LC50 (96 h) > 100 mg/L (nominal)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

100 mg/L