Pyrazole

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pyrazole

EC Number:

206-017-1

EC Name:

Pyrazole

Cas Number:

288-13-1

Molecular formula:

C3H4N2

IUPAC Name:

1H-pyrazole

Details on test material:

Name of test substance: Pyrazol
Batch No.: Pyrazol 27/90
Purity: 100%
Date of manufacture: April 20, 1989
Physical state/appearance: solid (melt)/white-colourless
Storage conditions: was stored at room temperature
Stability: Stability was ensured for at least the study period.
Homogeneity: was guaranteed by purity

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

strain: SPF Wistar/Chbb : THOM ; breeding facility: Dr. K . Thomae GmbH, D-7950 Biberach, FRG)
Mean body weight at the beginning of the study: male animals 285 +- 4.0 g, female animals 188 +- 2 .1 g.
Age at the beginning of the study: approx . 8- 9 weeks
The animals were identified by color marking on the tail.
The animals were offered KLIBA rat/mouse laboratory diet 24-343-4 10 mm pellets, Klingentalmuhle AG, CH-4303 Kaiseraugst, Switzerland, and drinking water ad libitum during the post-exposure observation period.
The animals were kept in fully air-conditioned rooms in which a temperature in the range 20-24°C and relative humidity in the range 30-70% were regulated by means of a central air-conditioning system.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

0.37 mg/l

No. of animals per sex per dose:

5

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.37 mg/L air

Any other information on results incl. tables

Cumulated lethality on day	male	female
0	0/5	0/5
1	0/5	0/5
2	0/5	0/5
7	0/5	0/5
14	0/5	0/5
Total at end of the study	0/5	0/5

Time after beginning of exposure	< ¼ h	¼ h	½ h	1 h	2 h	3 h	4 h
Animals without findings					10	10	10
Wiping of snouts		10
Restlessness		10	10	10
Attempts to escape	10

 

The body weight gain of male rats was not affected. The body weight gain of the female rats was retarded in the second week of the observation period.

Necropsy findings: Sacrificed animals: No pathologic findings noted.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Regarding the results of the study, the LC50 of the test substance Pyrazole exceeds the maximum concentration that could be technically achieved (0.37 mg/L air).