4-Butoxy-2,3-difluor-4'-methyl-1,1'-biphenyl

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:

Feb. 27, 2013 - Jun. 17,2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1085 (Fish Acute Toxicity Test mitigated by humic acid)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

samples taken in duplicate from each concentration during limit test at 0, 24, 48, 72 and 96 h

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test item directly added into dilution water, ultrasonicated for 30 min. For the limit test WAF solutions with a nominal concentration of 100 mg/L was prepared. Aqueous test substance mixture was stirred for 24 h at 23-25°C.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Source: Guangzhou Hongfa Aquatic Animals Culture Company, China
- Batch No. F20121215
- Length at study initiation: mean 2.66 cm
- Weight at study initiation: mean 0.273 g

ACCLIMATION
- Acclimation period: Feeding fry were held for 13 days in holding tanks supplied with a continuous flow of aerated water before being used for testing. Fish to be used in the test was held for 7 days in water of the quality and temperature to be used in the test.
- Acclimation conditions (same as test or not): yes
- Type and amount of food during acclimation: crude protein >36.0%, crude fat >2.0%, crude fibre <3.0%, crude ash <12%, moisture <10.0%

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

123 +/- 1.49 mg/L CaCO3

Test temperature:

22.9 - 23.2°C

pH:

6.94-7.03

Dissolved oxygen:

81 - 87% of saturation

Nominal and measured concentrations:

Nominal concentration 100 mg/L (WAF), the concentration was within 80% of initial concentration

Details on test conditions:

TEST SYSTEM
- Aeration: no
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.7 - 0.8 g fish/L

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

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/8 h dark
- Light intensity: 1000 - 1500 lux

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

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1.0, 10.0, 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 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.:

> 0.19 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: 269 mg/L (potassium dichromate)

Sublethal observations / clinical signs:

Study design

The test item was tested in a GLP study according to OECD GL 203. A range-finding test and then a Limit Test were performed respectively. Nominal concentrations of 1 - 100 mg/L were used in the range-finding test, while the nominal concentrations of 100 mg/L water accomodated fraction (WAF) was used in the Limit Test. In the range-finding test, 5 fishes per treatment and no replicates were used and 7 fishes per group were used in the Limit Test. The test fishes were exposed for 96 hours to the test solution.

Results

During the test period, the pH values of the control media and test media were between 6.94 - 7.05, the dissolved oxygen values varied from 81 – 87 % of the air saturation at the test temperature, and the total hardness was in the range of 120 – 123 mg CaCO3/L. During the test, the temperature of the test media were maintained in the range of 22.9 - 23.2°C and all fishes in the control group were normal. With the same conditions, K2Cr2O7 was used as the positive control substance, and the resulting 24 h-LC50 was 269 mg/L. So the study met the acceptability criteria prescribed by the test protocol and the test was considered as valid. During the test period, all fish in the control group and treated group were alive and appeared normal. The results show that under valid static test conditions, the 96 h-LC50 of the test item is greater than the nominal concentration of 100 mg/L WAFs (measured concentration 0.19 mg/L), while the maximum concentration causing no mortality (96 h-LC0) is equal to the nominal concentration of 100 mg/L WAFs (measured concentration 0.19 mg/L).

Conclusion

In this study no toxic effects were observed within 96 h. Therefore, the LC50 is determined to be >100 mg/L (WAF) and > 0.19 mg/L (measured concentration).

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test item to Zebra fish (Brachydanio rerio) was determined in a study according to OECD GL 203. For the limit test a WAF (water accomodated fraction) of 100 mg/L was prepared, the measured concentration was 0.19 mg/L. No toxic effects were observed within 96 h. Therefore, the LC50 is determined to be >100 mg/L (WAF) and > 0.19 mg/L (measured concentration).

Description of key information

The acute toxicity of the test item to Zebra fish (Brachydanio rerio) was determined in a study according to OECD GL 203. For the limit test a WAF (water accomodated fraction) of 100 mg/L was prepared, the measured concentration was 0.19 mg/L. No toxic effects were observed within 96 h. Therefore, the LC50 is determined to be >100 mg/L (WAF) and > 0.19 mg/L (measured concentration).