4-bromo-2,2-diphenylbutanenitrile

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:

2016-09-30 to 2016-10-26

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

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, December 14, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: I16AB0081
- Expiration date of the lot/batch: 2018-01-11 (retest date)
- Purity test date: 2016-02-18 (certificate of analysis release date)
- Purity: 99.3% (chromatographic purity by GC)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions: not indicated
- Solubility and stability of the test substance in the solvent/vehicle: <0.01 g/L in water

Analytical monitoring:

yes

Details on sampling:

- Sampling method: singular samples for possible analysis were taken from the limit concentration and the control at t=0, t=48h and t=96h. Volume was 2.0 ml.
- Sample storage conditions before analysis: the samples were stored in a freezer. Additionally, reserve samples of 2.0 mL were taken for possible analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with a loading rate of 100 mg/L applying a three-day period of magnetic stirring to ensure maximum dissolution of the test item in test medium. The resulting aqueous mixture was filtered through a 0.45 µm membrane filter (Whatman; RC55) to remove the undissolved fraction of the test item. The filter was pre-conditioned with a small volume of test solution that was discarded. The obtained Saturated Solution (SS) was used as the highest test concentration. The lower test concentrations were prepared by subsequent dilutions of the SS in test medium.
- Controls: yes
- Evidence of undissolved material (e.g. precipitate, surface film, etc): All final test solutions were clear and colourless

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp
- Source: Zodiac, proefacc, "De Haar Vissen", Wageningen University and Research Centre, The Netherlands
- Length at study initiation (length definition, mean, range and SD): range-finding test: 3.9 ± 0.4 cm, limit test: 3.5 ± 0.3 cm
- Weight at study initiation (mean and range, SD): range-finding test: 0.84 ± 0.29 g, limit test 0.64 ± 0.16 g
- Feeding during test: no

ACCLIMATION
- Acclimation period: at least 12 days after delivery
- Acclimation conditions (same as test or not): yes
- Type and amount of food: pelleted fish food
- Feeding frequency: daily
- Health during acclimation (any mortality observed): mortality less than 5% seven days before test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

not reported

Test temperature:

20.6-21.1°C

pH:

7.7-8.2

Dissolved oxygen:

3.6--9.2
In the limit test, the dissolved oxygen concentration was below 5 mg/L after 24 hours of exposure in the limit concentration. Evaluation: Fish coloration and behaviour returned to normal with increased oxygen supply and no mortality was observed indicating that this had no impact on the condition of the fish.

Salinity:

not relevant

Nominal and measured concentrations:

Range-finder:
Nominal concentrations: 100% of a SS prepared at 100 mg/L
Measured concentrations at t=0h: 0.822 mg/L
Measured concentrations at t=24h: 0.477 mg/L
Measured concentrations at t=96h: 0.288 mg/L

Final test:
Nominal concentrations: 100% of a SS prepared at 100 mg/L
Measured concentrations at t=0h: n.d., 0.892 mg/L
Measured concentrations at t=24h: n.d., 0.414 mg/L
Measured concentrations at t=96h: n.d., 0.297 mg/L
Geometric mean measured concentration: 0.48 mg/L
n.d. = not detected

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Material, size, headspace, fill volume: 6.5L, all-glass filled with 5L test solution
- Aeration: Aeration was introduced after 24 hours of exposure.
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): not reported
- No. of vessels per control (replicates): not reported
- Biomass loading rate: 0.90 g fish/L

OTHER TEST CONDITIONS
- Photoperiod: 16h light daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Fish were considered to be dead when no reaction was observed after touching the caudal peduncle and visible breathing movements were absent.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none (limit test)
- Range finding study: yes
- Test concentrations:1.0, 10 and 100% SS prepared at 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

pentachlorophenol

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 100% v/v saturated solution, equivalent to a loading rate of 100 mg/L

Details on results:

- Mortality of control: none
- Other adverse effects control: no
- Abnormal responses: none
- No mortality was observed during the test at the limit loading rate of 100 mg/L.
- The geometric mean measured concentration during the test was 0.48 mg/L.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50/LC50: 96-h LC50 = 0.24 mg/L.

Reported statistics and error estimates:

No LC50 could be calculated because the test item proved to be non-toxic (LC50 > maximum soluble concentration tested).

Validity criteria fulfilled:

yes

Remarks:

Dissolved oxygen concentration was < 5 mg/L after 24h of exposure in the limit concentration. Evaluation: Fish coloration and behaviour returned to normal with increased oxygen supply

Conclusions:

The acute toxicity of T000625 to carp was determined in a 96-hour static limit test according to the OECD guideline 203. Under the conditions of the present study, the 96h-LC50 was beyond the maximal loading rate tested, i.e. the LL50 was > 100 mg/L. No mortality was observed in the study. The geometric mean measured concentration at this loading rate was 0.48 mg/L (i.e. the maximum soluble fraction in a saturated solution prepared at a loading rate of 100 mg/L). The results of the test can be considered reliable without restriction.

Description of key information

The study of Migchielsen (2017), investigating the acute toxicity of T000625 in carp according to OECD guideline 203, was considered as the key study for endpoint coverage. No mortality was observed at the limit loading rate of 100 mg/L, i.e. the LL50 was > 100 mg/L. The geometric mean measured concentration at this loading rate was 0.48 mg/L (i.e. the maximum soluble fraction in a saturated solution prepared at a loading rate of 100 mg/L). Based on the results it can be concluded that T000625 is not harmful to fish.