1H-Pyrazolo[3,4-c]pyridine-3-carboxylic acid, 4,5,6,7-tetrahydro-1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxo-1-piperidinyl)phenyl]-, ethyl ester

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:

16 September 2016 - 10 October 2016

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)

Version / remarks:

2008

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

Version / remarks:

2000

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Solubility in water: 0.0115 g/L

Analytical monitoring:

yes

Details on sampling:

Samples were taken from all test concentrations and the control according to the schedule below.
Frequency: at t=0, t= 96 h
Volume: 2.4 mL
Storage: Samples were stored in a freezer until analysis.

Additionally, single reserve samples of 2.4 mL were taken from all test solutions for possible analysis. If not already used, these samples were stored in a freezer for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
- Method: the test material was not completely soluble in test medium at the initial concentration prepared. No correction was made for the purity/composition of the test item. Weighing and preparation were as much as possible performed in the dark or under dimmed light conditions. The glass ware used for test solution formulation was wrapped in aluminum foil. Preparation of test solutions started with a loading rate of 100 mg/L applying 2 days of magnetic stirring to ensure maximum dissolution of the test item in the test medium. The resulting dispersion was filtered through a 0.45 μm membrane filter to remove the fraction of undissolved test item. This resulted in a clear and colourless Saturated Solution (SS) that was used as highest test concentration. The lower test concentrations for the range-finding test were prepared by subsequent dilutions of the SS in test medium. All final test solutions were clear and colourless.
- Controls: test medium without test item or other additives (blank-control)

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 (final test): 2.4 +/- 0.2 cm
- Weight at study initiation (final test): 0.16 +/- 0.06 g
- Feeding during the test: no feeding from 24 hours prior to the test and during the total test period.

ACCLIMATION
- Acclimation period: at least 12 days after delivery
- Acclimation conditions: same as test conditions
- Type and amount of food during acclimation: daily with pelleted fish food (Essence (300-500 um), Coppens International bv, Helmond, The Netherlands)

BREEDING:
- Method of breeding: F1 from a single parent-pair bred in UV-treated water.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

180 mg CaCO3/L

Test temperature:

21.0 - 21.9 °C

pH:

7.7 - 8.1

Dissolved oxygen:

6.8 - 8.8 mg O2/L

Nominal and measured concentrations:

Nominal test concentrations: 100% of a SS prepared at a loading rate of 100 mg/L
Measured concentrations after 96 hours: 11.1 mg/L
Analysis of the samples taken from the SS at the start of the limit test showed a measured concentration of 11.2 mg/L. The concentration measured at the study end was 11.0 mg/L (99% relative to initial). Hence, the average exposure concentration was 11.1 mg/L, being the maximum solubility in test medium.

Details on test conditions:

TEST SYSTEM
- Test vessel: 8 litres, open, all-glass test vessels, fill volume: 6 litres
- 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: 0.19 g fish/Litre

TEST MEDIUM / WATER PARAMETERS
- Standard medium used: yes, adjusted ISO medium
- Source of dilution water: tap water form reversed osmosis
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours daily, dimmed conditions (10 lux)

EFFECT PARAMETERS MEASURED: mortality and sublethal observations were made at 3¾, 24, 48, 72 and 96 hours. In addition, every afternoon from day 0 observations were made for any dead or severly distressed fish.

- Measurements for water quality parameters (pH, dissolved oxygen and temperature) were made daily in all vessels with surviving fish.

RANGE-FINDING TEST:
- Test concentrations: 1.0, 10 and 100% of a SS prepared at a loading rate of 100 mg/L
- Results used to determine the conditions for the definitive study: yes, no mortality was observed at any of the tested concentrations.

Reference substance (positive control):

yes

Remarks:

pentachlorophenol (January 2016)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 11.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- No mortality or clinical effects were observed.
- No 96-h LC50 could be calculated because the test item proved to be non-toxic (LC50 > maximum soluble concentration).

- The measured concentrations deviated by more than 20% from nominal, therefore results were based on the average exposure concentration. The measured concentration at t=96 was 99% of the initial measured concentration at t=0.
- Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout the duration of the study.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Mortality: 20% at 0.22 mg/L, 100% at 0.46 mg/L
- LC50: 0.24 mg/L
- Other: results fell within the historical range, therefore the sensitivity of the carp originating from the batch used in this study is acceptable.

Validity criteria fulfilled:

yes

Remarks:

For details on validity criteria see 'overall remarks' section.

Conclusions:

The 96h-LC50 exceeded 11.1 mg/L, being the average measured concentration in a saturated solution prepared at a loading rate of 100 mg/L. This concentration was considered the maximum soluble concentration in test medium.

Description of key information

The 96h-LC50 exceeded 11.1 mg/L, being the average measured concentration in a saturated solution prepared at a loading rate of 100 mg/L. This concentration was considered the maximum soluble concentration in test medium.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

11.1 mg/L