Benzoic acid, 3-(trifluoromethyl)-, methyl ester

Long-term toxicity to fish

Administrative data

Endpoint:

fish, juvenile growth test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 215 (Fish, Juvenile Growth Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

457-830-5

EC Name:

-

Cas Number:

2557-13-3

Molecular formula:

Hill formula: C9 H7 F3 O2

IUPAC Name:

Methyl, 3-Trifluoromethylbenzoate

Constituent 2

Reference substance name:

607-745-6

EC Number:

607-745-6

IUPAC Name:

607-745-6

Details on test material:

- Name of test material : Methyl, 3-trifluoromethyl benzoate
- Physical state: liquid
- Analytical purity: 99.77%
- Lot/batch No.: 250037A
- Expiration date of the lot/batch: March 10, 2009
- Stability under test conditions: stable
- Storage condition of test material: room temperature in the dark

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain: Oncorhynchus mykiss
- Age at study initiation (mean and range, SD): juveniles
- Weight at study initiation (mean and range, SD): 0.85 +/- 0.05 g
- Method of breeding: all fish are obtained and held in the laboratory for at least 12 days before the start of the test.They must be held in water of the quality to be used in the test for at least 7 days immediately before testing under the following conditions:
Light 12-16 hours photoperiod daily
Temperature 12-14 °C +/- 2°C
Oxygen conc. at least 80% of the air saturation value
Feeding three times /week or daily until 24 h before the test is started


FEEDING DURING TEST
- Food type: fish food
- Amount and Frequency: 17 mg/fish/day (= 2% of the initial individual body weight)

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

28 d

Test conditions

Hardness:

250 mg/l as CaCO3

Test temperature:

12-14 °C

pH:

7.5-8.0

Dissolved oxygen:

79-110 % of the air saturation value

Details on test conditions:

- Test vessel: 25 litre glass aquaria with 20 litre test medium
- No. of replicates: 1
- Temperature: 12-14°C
- Fish per replicate: 10
- Loading rate: Mean at the beginning: 0.42 g fish/L
Max after 28 days: 0.89 g fish/L
- Light Regime: 16 h light : 8 h dark;
30 min dawn/dusk period was provided
- Light Intensity:430 - 1160 lux
- Aeration of the Test Water: The test media were slightly aerated during the test.

Reference substance (positive control):

yes

Remarks:

reconstituted water

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Basis for effect:

other: growth rate, lenght and weight

Effect concentrations 2

Duration:

28 d

Dose descriptor:

other: LLC

Effect conc.:

4.5 mg/L

Nominal / measured:

nominal

Effect concentrations 3

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

4.5 mg/L

Nominal / measured:

nominal

Basis for effect:

other: growth rate, length and weight

Results with reference substance (positive control):

No mortality or symptoms of inoxication were observed during the test in the control.

Any other information on results incl. tables

At test start dark coloration occurred in all treatment groups (0.4 -10.0 mg/L) and additionally tumbling swimming at 4.5 mg/L. However after one day of exposure no behaviour abnormalities occurred from 0.4 to 2.1 mg/L. At 4.5 mg/L sub-lethal effects like distended abdomen, fish lying on side or back or food refusal occurred from day 12 onwards. Additionally at this treatment group the fish were mainly swimming at the water surface. At 10 mg/L dark coloration, tumbling during swimming, and fish lying on side or back occurred at experimental start. In the following days distended abdomen, convulsions, strong ventilation and exophthalmus came along. After 2 days one fish was found dead at this treatment group. Additional mortality occurred at day 6, 7, 8, 10, 17 and 19 so that all fish in this treatment group were dead on day 19 of the experiment (for details compare table 5). At the next lower concentration of 4.5 mg test item/L one fish died on day 23. In the following days until the end of the test a total number of 4 fish had died in this test concentration. Fish in this exposure group showed sub-lethal effects, like swimming at the surface, dark colouration, convulsions and apathy.

The mortality at 10 mg/L was statistically significant (Fisher´s Exact binominal Test, α = 0.05).

The decrease in body weight and length was statistically different from the control in the 4.5 mg test item/L treatment group (weight: Student t-test with Bonferroni adjustment, α = 0.05; length: Welch t-test with Bonferroni adjustment, α = 0.05).

The pseudo specific growth rate was calculated as follows:

W₁= mean wet weight at test start
W₂= wet weight at test end
t₁= time (days) at test start
t₂= time (days) at the second assessment time

 

A statistical difference in growth rate was evaluated at 4.5 mg test item/L (Dunnett’s multiple t-test, α = 0.05).

Analytical results

In the freshly prepared test media collected at day 0, 9, 19 and 21 just before introduction of the fish 85% of the nominal test concentrations were found. In the aged test media collected at day 2, 12, 21 and 23 (after 48 and 72 hours of exposure) 37% of the nominal values were determined. Thus, during the test period the fish were exposed to a geometric mean value of 56% of nominal. All reported results are related to geometric mean concentrations of the test item.

Applicant's summary and conclusion

Conclusions:

Based on the test results the 28 days no observed effect concentration (NOEC) of Methyl, 3-trifluoromethyl benzoate for Rainbow Trout (Oncorhynchus mykiss) was determined to be nominal 2.1 mg test item/L (1.2 mg test item/L mean measured). The 28 days lowest effect concentration (LOEC) was determined to be nominal 4.5 mg test item/L (2.1 mg test item/L mean measured), both values based on growth rate length and weight. The lowest lethal concentration was determined to be nominal 4.5 mg test item/L (2.1 mg test item/L; mean measured, based on sub-lethal effects).