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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Acceptable, well documented publication/ study report which meets basic scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Liver Cell Necrosis in Rats After Prolonged Ethanol Ingestion Under the Influence of an Alcohol- Dehydrogenase Inhibitor
Author:
Lelbach W.K.
Year:
1969
Bibliographic source:
Experientia 25/8, 816-18

Materials and methods

Principles of method if other than guideline:
The LD50 was determined after a 24-hour fast with free access to tap-water.
GLP compliance:
not specified
Test type:
standard acute method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Pyrazole, easily soluble in water and alcohol (purchased from Messrs. D. Schuchardt, Munich), was used as 1% and 5% w/v aqueous solutions.

Test animals

Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 205-220 g
- Housing: each housed in individual cages
- Diet: commercial standard solid diet (Altromin-R) ad libitum
- Water: ad libitum

Administration / exposure

Route of administration:
oral: unspecified
Doses:
840-1214 mg/kg
No. of animals per sex per dose:
2 groups of 40 rats each
Control animals:
not specified
Details on study design:
The LD50 was determined after a 24-hour fast with free access to tap-water.

Results and discussion

Effect levels
Sex:
not specified
Dose descriptor:
LD50
Effect level:
1 010 mg/kg bw

Any other information on results incl. tables

The minimal lethal dose was 850 mg/kg. After single doses larger than 1000 mg/kg leading to a comatose state with death occurring within 12 -36 h, no liver cell alterations were seen microscopically; livers of rats dying 6 -11 days after 850 -1000 mg/kg showed extensive centrolobular necrosis with inflammatory reactions and appearance of fat ill surviving liver cells.

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
LD50 (rat): 1010 mg/kg
Executive summary:

The oral LD50 of the test substance was determined after a 24-hour fast with free access to tap-water. The minimal lethal dose was 850 mg/kg. Single doses larger than 1000 mg/kg lead to a comatose state with death occurring within 12 -36 hours with no liver cell alterations observed microscopically. Liver effects were observed in rats dying 6 -11 days after 850 -1000 mg/kg. The LD50 was 1010 mg/kg.