2,4-dihydro-5-methyl-3H-pyrazol-3-one

Acute Toxicity: other routes

Administrative data

Endpoint:

acute toxicity: other routes

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: scientifically acceptable study report, no relevant route of exposure

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Principles of method if other than guideline:

according to BASF-internal standard

GLP compliance:

no

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,4-dihydro-5-methyl-3H-pyrazol-3-one

EC Number:

203-565-3

EC Name:

2,4-dihydro-5-methyl-3H-pyrazol-3-one

Cas Number:

108-26-9

Molecular formula:

C4H6N2O

IUPAC Name:

2,4-dihydro-5-methyl-3H-pyrazol-3-one

Details on test material:

Name of the test substance used in the study report: Methylpyrazolon feucht ber. 100%

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Young adult animals with a comparable weight were used (age at study start: about 12 weeks).
Acclimatization period: at least one week
Five animals per cage (type: stainless steel wire mesh cages, DK-III).
The animals were identified via cage cards.
Room temperature: 20 - 26°C
Relative humidity: 45 - 75%
Day/night rhythm: 12 h light and 12 h darkness
The animals were offered a standardized animal laboratory diet as well as tap water ad libitum. Food depreviation 16 hours before substance administration (water was available ad libitum).

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

water

Details on exposure:

0.5% aqueous CMC; the aqueous suspension corresponds to the physiological medium.
Concentration used: 21.5% (G/V)
Application volume: 10 ml/kg

Doses:

2150 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Observation period: 18 days
Recording of signs and symptoms: < 15 min, 15 min, 30 min, 1 h, 2 h, 4 h and 5 h after administration, then once on working days. Check for moribund or dead animals twice each working days and once on public holidays.
16 hours before sacrifice food depreviation; then necropsy with macroscopic-pathological examination. Necropsy of animals that died as soon as possible.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 150 mg/kg bw

Mortality:

None

Clinical signs:

Dyspnea, apathy, staggering, trembling, urine light-orange coloured, ruffled fur, poor general state

Body weight:

Mean body weight male animals: 180 g at study start, 275 g after 13 days
Mean body weight female animals: 170 g at study start, 215 g after 13 days

Gross pathology:

Sacrificed animals: nothing abnormal detected.