4-methylpyrazole

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-methylpyrazole

EC Number:

231-445-0

EC Name:

4-methylpyrazole

Cas Number:

7554-65-6

Molecular formula:

C4H6N2

IUPAC Name:

4-methyl-1H-pyrazole

Details on test material:

- Name of test material (as cited in study report): 4-Methylpyrazol
- Physical state: liquid, clear, yellow
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

To each sample of a volume of 2 mL, 5 mL internal standard solution were added.

Test solutions

Vehicle:

no

Details on test solutions:

Separately for each concentration 0.4637, 1.00, 2.15, 4.64 and 10.00 g test substance were added to the test water using an ultra-turrax stirrer.
From the beginning of preparing the test solutions until termination of placing the fish into the aquaria 20 minutes were needed.

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra fish (Brachydanio rerio)
- Strain: HAM. and BUCH.
- Source: Charles River Aquatics, Someren, Netherlands
- Age at study initiation: about 3 months
- Length at study initiation: 3.32 (2.5 - 4.2) cm
- Weight at study initiation: 0.203 (0.10 - 0.39) g
- Food type: "TETRA MIN" standard feed for aquarium fish, TETRA - WERKE, MELLE, FRG, ad libitum; and on workdays generally additionally live artemia

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

250 mg/L (CaCO3)

Test temperature:

22 °C

pH:

8.0 - 8.6

Dissolved oxygen:

6.9-9.1 mg/L

Nominal and measured concentrations:

46.4, 100, 215, 464, 1000 mg/L (nominal)
98.3-105.1% recovered in analysis

Details on test conditions:

TEST SYSTEM
- Test vessel: All-glass aquaria (30 x 22 x 24 cm); one aquarium for each test group
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: 10 liters (water depth about 17 cm)
- Aeration: with oil-free air
- Type of flow-through (e.g. peristaltic or proportional diluter): non-chlorinated tap water, passed through a charcoal filter
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.2 g/L

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

ca. 215 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 468 - 1 010 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

Determination or calculation of the median lethal concentration (LC50), the NOEC and the symptoms of the nominal concentrations after 1, 4, 24, 48, 72 and 96 hours, the analytical concentrations after 1, 96 and 1+96 hours and, if possible, the LC5 and the LC95 for the calculations using the probit analysis.

Any other information on results incl. tables

Sublethal observations / clinical signs:

Measured concentration (mg/L)	Number of fish start	Number of fish dead after 96h
45.6	10	0
100	10	0
215	10	0
468	10	0
1010	10	10

Applicant's summary and conclusion

Validity criteria fulfilled:

yes