1H-Pyrazole

  • 1,2-Diazole
Formula
C3H4N2
Structure
Description
Colorless crystals.
Uses
Chelating agent.

Registry Numbers and Inventories.
CAS
288-13-1
EC (EINECS/ELINCS)
206-017-1
EC Class
harmful, irritant
R 22 36/37/38
S 26 36/37/39
RTECS
UQ4900000
RTECS class
Reproductive Effector
Merck
12,8144
Beilstein/Gmelin
103775
Beilstein Reference
5-23-04-00122
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C3H4N2
Formula mass
68.08
Melting point, °C
66 - 68
Boiling point, °C
186
Vapor pressure, mmHg
0.89 (25 C)
Density
1.026 - 0.952 g/cm3 (70 - 155 C)
Solubility in water
Very soluble
Surface tension
31.48 g/s2 (80.5 C)
Refractive index
1.4203 (20 C)
pKa/pKb
11.53 (pKb)
Partition coefficient, pKow
0.32
Heat of fusion
14.41 kJ/mol
Heat of vaporization
40.6 kJ/mol
Heat of combustion
-1858 kJ/mol

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
Handling
Wash thoroughly after handling. Use with adequate ventilation. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Provide ventilation.
Disposal code
3
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents, acids.
Decomposition
Nitrogen oxides, carbon monoxide, carbon dioxide, nitrogen.

Fire.
Flash Point,°C
88
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Extinguishing media: Use agent most appropriate to extinguish fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Hazards
During a fire, irritating and highly toxic gasesmay be generated by thermal decomposition or combustion.

Health.
Exposure effects
May cause reproductive and fetal effects.
   Ingestion
May be harmful if swallowed.
   Inhalation
Inhalation of dust may cause respiratory tract irritation.
   Skin
May cause skin irritation.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
HS Code
2933 19 90