3,4-dihydroxybenzonitrile

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:

2017

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:

yes

Remarks:

Range-finding test: The difference in pH of the culture and the 100 mg/L concentration exceeded 0.5 unit. Evaluation: No effects on the fish were observed directly after initiation of the test thus this was assumed not to have an impact on the results.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule below.
Frequency at t=0 h and t=96 h
Volume 3.6 mL
Storage Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility. Storage stability of samples under these conditions was demonstrated in project 515444.

Additionally, reserve samples of 3.6 mL were taken from all test solutions for possible analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The batch of CH02906 tested was a white to brownish powder with a purity of 99.9% and completely soluble in test medium at the concentrations tested. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with a concentration of 100 mg/L applying a stirring period of approximately 10 minutes to accelerate dissolution of the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the 100 mg/L concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.

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.
- Age at study initiation (mean and range, SD): /
- Length at study initiation (length definition, mean, range and SD):
Range-finding test: 3.1 ± 0.1 cm
Final test: 2.2 ± 0.2 cm
- Weight at study initiation (mean and range, SD):
Range-finding test: 0.45 ± 0.03 g
Final test: 0.12 ± 0.05 g
- Method of breeding: F1 from a single parent-pair bred in UV-treated water.

ACCLIMATION
- Acclimation period: At least 12 days after delivery
- Acclimation conditions (same as test or not): Adjusted ISO medium, formulated using RO-water (tap-water purified by reverse osmosis; GEON Waterbehandeling, Berkel- Enschot, The Netherlands) with the following composition:
CaCl2.2H2O 211.5 mg/L
MgSO4.7H2O 88.8 mg/L
NaHCO3 46.7 mg/L
KCl 4.2 mg/L
- Type and amount of food during acclimation: Daily with pelleted fish food (Essence (300-500 um), Coppens International bv, Helmond, The Netherlands)
- Health during acclimation (any mortality observed): In the batch of fish used for the test, mortality during the seven days prior to the start of the test was less than 5%.

FEEDING DURING TEST
No feeding from 24 hours prior to the test and during the total test period

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

T: 20-24°C, constant within 2°C

pH:

6.0-8.5, constant within 1 unit

Dissolved oxygen:

oxygen > 60% of air saturation

Nominal and measured concentrations:

nominal: 10, 18, 32, 56 and 100 mg/L
Measured concentrations were in agreement with nominal at the start of the test (99-106%) and remained stable during the exposure period (93-100% of nominal).

Details on test conditions:

TEST SYSTEM
3.5 litres, all-glass, containing 3 litres of test solution
- Aeration: Aeration was introduced after two days of exposure and maintained until the end of the test. Note that aeration was introduced after 2 days of exposure, as the oxygen concentration tended to drop below the optimum level for testing with carp, i.e. below 5 mg/L.
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.28 g fish/Litre, i.e. 7 fish per 3 litres of test medium


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Test concentrations: 6 (0, 10, 18, 32, 56 and 100 mg/L )

Reference substance (positive control):

yes

Remarks:

Reference test with pentachlorophenol (PCP) in February 2017

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

All fish exposed to 100 mg/L died within 24 hours of exposure. No mortality or clinical effects were observed at or below 56 mg/L during the test period. Since no mortality was observed in the control this test was considered valid.

Results with reference substance (positive control):

The 96h-LC50 for carp exposed to PCP was 0.32 mg/L (95 % confidence interval between 0.22 and 0.46 mg/L). This effect was already reached within 24 hours of exposure.

Reported statistics and error estimates:

Effect parameters based on analytically confirmed nominal concentrations:
24h LC50 (95% confidence interval) = 75 (56 - 100) mg/L
48h LC50 (95% confidence interval) = 75 (56 - 100) mg/L
72h LC50 (95% confidence interval) = 75 (56 - 100) mg/L
96h LC50 (95% confidence interval) = 75 (56 - 100) mg/L

Validity criteria fulfilled:

yes

Conclusions:

The 96h-LC50 was 75 mg/L (95% confidence interval between 56 and 100 mg/L) based on analytically confirmed nominal exposure concentrations and was already reached after 24 hours of exposure.

Executive summary:

The objective of the study was to evaluate CH02906 for its ability to generate acute toxic effects in Cyprinus carpio during an exposure period of 96 hours and, if possible, to determine the LC₅₀at all observation times.

The study procedure described in this report was based onthe OECD guideline No. 203 (1992).

The batch of CH02906 tested was a white to brownish powder with a purity of 99.9% and completely soluble in test medium at the concentrations tested.

A final test was performed based on the results of a preceding range-finding test. Seven fishper group were exposed to a control and to nominal CH02906 concentrations of 10, 18, 32, 56 and 100 mg/L. The total exposure period was 96 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test or upon complete mortality in a test group.

Measured concentrations were in agreement with nominal at the start of the test (99-106%) and remained stable during the exposure period (93-100% of nominal. Therefore, the LC₅₀values were based on the nominal test concentrations.

The study met the acceptability criteria prescribed by the study plan and was considered valid.

The 96h-LC₅₀was 75 mg/L (95% confidence interval between 56 and 100 mg/L) based on analytically confirmed nominal exposure concentrations and was already reached after 24 hours of exposure.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

75 mg/L