Chemistry informtion about Cis-2,3-Epoxybutane (CAS NO.1758-33-4) is:
IUPAC Name: (2S,3R)-2,3-dimethyloxirane
Synonyms: (2s,3r)-2,3-Dimethyl-Oxirane ; 2,3-Dimethyl-Oxirane (Z) ; 3-Dimethyl-Cis-Oxiran ; 3-Epoxy-Cis-Butan ; Butane, 2,3-Epoxy-, Cis- ; Cis-2,3-Dimethyloxirane ; Cis-2-Butene Epoxide ; Cis-2-Butene Oxide
Product Categories: Organics
MF: C₄H₈O
MW: 72.11 
Density: 0.855 g/cm³
Melting Point: −84-−83 °C(lit.)
Flash Point: −7 °F
Boiling Point: 56.5 °C at 760 mmHg
Vapour Pressure: 239 mmHg at 25°C 
Enthalpy of Vaporization: 28.69 kJ/mol
Refractive Index: n20/D 1.383(lit.)
Storage temp.: Flammables area
Sensitive: Moisture Sensitive
BRN: 79770
Following is the molecular structure of Cis-2,3-Epoxybutane (CAS NO.1758-33-4) is:

Mutation data reported. When heated to decomposition it emits acrid smoke and irritating vapors.
Hazard Codes:
F
Xi
Xn
Risk Statements:
R11:Highly flammable. 
R36/37/38:Irritating to eyes, respiratory system and skin. 
R20/21/22:Harmful by inhalation, in contact with skin and if swallowed.
Safety Statements:
S16:Keep away from sources of ignition. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection.
RIDADR: UN 3271 3/PG 2
WGK Germany: 3
RTECS: EK3855020
F:
F 21: Sensitive to humidity.
HazardClass: 3
PackingGroup: II

Cis-2,3-Epoxybutane (CAS NO.1758-33-4) is a clear colourless liquid.
First Aid Measures:
Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.
Skin: Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes.
Ingestion: Get medical aid. Wash mouth out with water.
Inhalation: Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
Notes to Physician: Treat symptomatically and supportively. 
Handling and Storage
Handling: Use spark-proof tools and explosion proof equipment. Avoid breathing dust, vapor, mist, or gas. Avoid contact with skin and eyes. Avoid ingestion and inhalation. Use only in a chemical fume hood.
Storage: Keep away from sources of ignition. Store in a cool, dry place. Keep container closed when not in use. Flammables-area. Store under an inert atmosphere. May form explosive peroxides on prolonged storage.