Benzonitrile, 4-[(1,6-dihydro-4-hydroxy-6-oxo-2-pyrimidinyl)amino]-

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:

2015-07-31 to 2015-09-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The lenght of fish was between 1.9 and 2.7 cm instead of 2.0 and 4.0 cm. The deviation was minimal. Moreover, smaller fish provide a worst-case-scenario.

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

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: I15CB0987
- Expiration date of the lot/batch: 2016-07-29 (retest date)
- Purity test date:2015-08-17

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: solubility in water: <0.01 g/L

Analytical monitoring:

yes

Details on sampling:

- Sampling method: singular samples for possible analysis were taken form all test concentrations with surviving fish and the control at t=0 and t=96h. Volume was 3.6 ml.
- Sample storage conditions before analysis: the samples were stored in a freezer. Additionally, reserve samples of 3.6 mL were taken for possible analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to the expected low water solubility of the test item, saturated solutions of the test item were prepared. The preparation of tests solutions started with a loading rate of 100 mg/L applying a two-day period of magnetic stirring at room temperature, mostly in the dark. The obtained mixture was filtrered through a 0.45 µm membrane (RC55, Whatman) to remove the undissolved fraction. The filter was pre-conditioned with a small volume of test solution that was discarded. The obtained undiluted filtrate was used as the highest test concentration. The lower test concentrations were prepared by subsequent dilutions of this undiluted filtrate in test medium. The final test solutions were all clear and colourless.
- Controls: yes
- Evidence of undissolved material (e.g. precipitate, surface film, etc): 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: 2.2 ± 0.1 cm, limit test: 2.3 ± 0.4 cm
- Weight at study initiation (mean and range, SD): range-finding test: 0.23 ± 0.06 g, limit test 0.40 ± 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:

21.0-22 °C

pH:

7.2-7.7

Dissolved oxygen:

5.8-8.8

Salinity:

not relevant

Nominal and measured concentrations:

Nominal concentrations: 100 mg/L
Measured concentrations at t=0h: 44.8 mg/L
Measured concentrations at t=24h: 44.4 mg/L
Measured concentrations at t=96h: 44.3 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Material, size, headspace, fill volume: 6.5L, all-glass filled with 6L test solution
- Aeration: not during the test
- 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: 0.47 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 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:

LC50

Effect conc.:

> 39 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: v/v % saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: none
- Other adverse effects control: no
- Abnormal responses: none

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50/LC50: 96-h LC50 = 0.32 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).

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of T002326 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 measured 96-h LC50 was >39 mg/L obtained at a loading rate of 100 mg/L, i.e. 100 % v/v saturated solution. In conclusion, the test item T002326 clearly had no toxic effect in Carp up to a measured concentration of 39 mg/L.The results of the test can be considered reliable without restriction.

Description of key information

A key study (Tobor-Kaplon, 2016) on the acute toxicity to Carp is available. The study revealed no toxic effects up to the limit of solubility in the test media. The 96 -h LC50 was > 39 mg/L (measured), corresponding to > 100 mg/L (loading rate). The test substance is considered not acutely harmful to fish. The results of this acute toxicity study to fish are used to derive the classification. Nevertheless, since in all test concentrations the overall survival was higher compared to the control, no effects were observed in the 100% SS and all validity criteria were met, there is no reason to perform a long-term toxicity study on fish. It can be assumed that a chronic study would not provide additional information that could improve the risk assessment.