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

Remarks on result:

other: maximum concentration achievable

Mortality:

No mortality was observed during the study.

Clinical signs:

other: Clinical signs included wiping of snouts, restlessness, and attempts to escape. All animals were clear of findings by 2 hours after the beginning of exposure.

Body weight:

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.

Gross pathology:

No pathologic findings noted.

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

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

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

Executive summary:

The acute inhalation toxicity potential of the test substance was studied in accordance with OECD Guideline 403. Five male and five female rats were exposed to the test substance for 4 hours at a concentration of 0.37 mg/L (maximum attainable concentration). No mortality or gross pathologic findings were noted was observed.