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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1987-08-06 - 1988-01-14
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study parameters are not described in detail (size of test chamber, concentration of test substance in the test chamber).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
not specified
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
3-methylpyrazole
EC Number:
215-925-7
EC Name:
3-methylpyrazole
Cas Number:
1453-58-3
Molecular formula:
C4H6N2
IUPAC Name:
3-methyl-1H-pyrazole
Test material form:
other: liquid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
Male Wistar rats of a departmental breeding strain with a minimum age of 60 days were used for the study. Before the start of the experiment, the animals lived in an area of 1270 cm3 with 10 individuals each and received food and water (communal tap network) ad libitum.
The ambient temperature was adjustable in the range of 20± 3°C, the humidity was averagely 80 %. The ambient noise level was in the range of 65 -80 dB. The experimental animals had lived under natural light conditions since birth.

The animals used had a mean body mass of 257 ± 19,8 g .

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
not specified
Vehicle:
air
Details on inhalation exposure:
The experimental set-up for inhalation tests with one component consists of the following components: compressed air bottle, pressure reducing valve and 2 needle valves from Zimmermann, vaporiser (capillary, frit) with thermostated liquid holder, thermostat, glass transition piece and distributor for the exposure chamber. The vapour-air mixture of the investigated substance was produced by compressed air flow at a total air flow rate of 200 l/h. The inhalation time was 4 hours.

Analytical verification of test atmosphere concentrations:
no
Duration of exposure:
4 h
Concentrations:
2065, 3380, 4180, 7930, 18750, 28110 mg/m3
No. of animals per sex per dose:
5
Control animals:
no

Results and discussion

Effect levels
Key result
Sex:
female
Dose descriptor:
LC50
Effect level:
> 28 000 mg/m³ air
Based on:
test mat.
Exp. duration:
4 h
Mortality:
No mortality was observed.
Clinical signs:
other: No abnormal clinical signs were observed.
Gross pathology:
No macroscopic organ alterations were observed.

Applicant's summary and conclusion

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute inhalation LC50 for 3-Methylpyrazole is greater than 28000 mg/m3 (highest technically achievable concentration).
Executive summary:

The acute inhalation LC50 for 3-Methylpyrazole is greater than 28000 mg/m3 (highest technically achievable concentration).