Calcium oxide

Structure of Calcium oxide (CAS NO.1305-78-8):

Empirical Formula: CaO
Molecular Weight: 56.0774g/mol
IUPAC Name: oxocalcium 
EINECS: 215-138-9 
Density: 3.3 g/mL at 25 °C(lit.)
Melting Point: 2570 °C
Boiling Point: 2850 °C(lit.)
Flash Point: 2850°C
Sensitive Air & Moisture Sensitive 
Stability: Stability Stable, but absorbs carbon dioxide from the air. Incompatible with water, moisture, fluorine, strong acids. 
Product Categories: Inorganics 
Canonical SMILES: O=[Ca]
InChI: InChI=1S/Ca.O
InChIKey: ODINCKMPIJJUCX-UHFFFAOYSA-N

 Calcium oxide (CAS NO.1305-78-8) is used in water and sewage treatment to reduce acidity, to harden, as a flocculant and a coagulant, and in bleaching; in agriculture to improve acidic soils; and in pollution control, in gas scrubbers to desulfurize waste gases and to treat many liquid effluents. It is also used in the metallurgical industry as a flux in the manufacture of steel.

 Calcium oxide (CAS NO.1305-78-8) is usually made by the thermal decomposition of materials such as limestone, that contain calcium carbonate  in a lime kiln.
                                 CaCO₃ → CaO + CO₂

Hazard Codes : C,Xi
Risk Statements : 34-41:  
34:  Causes burns 
41:  Risk of serious damage to eyes
Safety Statements : 26-36/37/39-45-25-39
26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice 
36/37/39:  Wear suitable protective clothing, gloves and eye/face protection 
45:  In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) 
25:  Avoid contact with eyes 
39:  Wear eye/face protection
RIDADR : 1910
WGK Germany : 1
F : 10-21-34:  Keep under argon.Sensitive to humidity.Sensitive to CO2.
HazardClass : 8
PackingGroup : III

OSHA PEL: TWA 5 mg/m³
ACGIH TLV: TWA 2 mg/m³
DFG MAK: 5 mg/m³
DOT Classification:  8; Label: Corrosive

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  Calcium oxide , its cas register number is 1305-78-8. It also can be called Airlock Bell CML(E) ; Bell CML(P) ; Burnt lime ; CALX ; CCRIS 7496 ; CML 21 ; CML 31 ; CML 35 ; Calcia ; Calcia (CaO) ; Calcium monoxide ; Calcium oxide ;
 Calcium oxide (CaO) ; Caloxal CPA ; Caloxol CP2 ; Caloxol W3 ; Calx usta ; Calxyl ; Caswell No. 147A ; Chaux vive ;
 Desical P ; EPA Pesticide Chemical Code 075604 ; Gebrannter kalk ; HSDB 1615 ; Lime ; Lime, burned ; Oxyde de calcium ; QC-X ; Quick lime ; Quicklime ; Rhenosorb C ; Rhenosorb F ; UNII-C7X2M0VVNH ; Unslaked lime ; Vesta PP ; Wapniowy tlenek . Calcium oxide (CAS NO.1305-78-8) is commonly known as burnt lime, lime or quicklime, which is a widely used chemical compound. It is a white, caustic and alkaline crystalline solid at room temperature. As a commercial product, lime often also contains magnesium oxide, silicon oxide and smaller amounts of aluminium oxide and iron oxide. The name lime (native lime) refers to a very rare mineral of the CaO composition.