Molecule structure of Propionyl peroxide (CAS NO.3248-28-0) :

IUPAC Name: propanoyl propaneperoxoate 
Molecular Weight: 146.1412 g/mol
Molecular Formula: C₆H₁₀O₄ 
Density: 1.086 g/cm³ 
Boiling Point: 168.7 °C at 760 mmHg 
Flash Point: 59.3 °C
Index of Refraction: 1.41
Molar Refractivity: 33.39 cm³
Molar Volume: 134.5 cm³
Polarizability: 13.23*10^-24 cm³
Surface Tension: 32.1 dyne/cm 
Enthalpy of Vaporization: 40.52 kJ/mol
Vapour Pressure: 1.6 mmHg at 25 °C 
log P (octanol-water): 1.500 
Water Solubility: 1.59E+04 mg/L 
Atmospheric OH Rate Constant: 9.14E-13 cm³/molecule-sec
XLogP3-AA: 1.1
H-Bond Acceptor: 4
Rotatable Bond Count: 5
Exact Mass: 146.057909
MonoIsotopic Mass: 146.057909
Topological Polar Surface Area: 52.6
Heavy Atom Count: 10
Complexity: 114
Canonical SMILES: CCC(=O)OOC(=O)CC
InChI: InChI=1S/C6H10O4/c1-3-5(7)9-10-6(8)4-2/h3-4H2,1-2H3
InChIKey: KOPQZJAYZFAPBC-UHFFFAOYSA-N
EINECS: 221-828-0

 Propionyl peroxide (CAS NO.3248-28-0) is used as an initiator in polymerization reactions.

Moderately toxic by inhalation. The pure material explodes at room temperature. When heated to decomposition it emits acrid smoke and fumes. See also PEROXIDES, INORGANIC; PEROXIDES, ORGANIC.
RIDADR: 3117
HazardClass: 5.2
PackingGroup: II

DOT Classification:  Forbidden

 Propionyl peroxide (CAS NO.3248-28-0) is also called 4-02-00-00723 (Beilstein Handbook Reference) ; BRN 1766068 ; Dipropionyl peroxide ; Peroxide, bis(1-oxopropyl) ; Peroxide, bis(1-oxopropyl) . Propionyl peroxide (CAS NO.3248-28-0) is available only as a 25% solution. Pure material poses a severe explosion hazard.  It is highly flammable. It may ignite spontaneously if exposed to air. Propionyl peroxide (in solution,content≤27%) is a good oxidizing agent. May cause ignition of organic compounds on contact . Reacts violently with strongly reduced material such as sulfides, nitrides, and hydrides. Many produce explosions or generate gases (toxic and nontoxic). Generally, dilute solutions (<70%) are safe, but the presence of a catalyst (often a transition metal such as cobalt, iron, manganese, nickel, or vanadium) as an impurity may even then cause rapid decomposition, a buildup of heat, and even an explosion. May become explosive when evaporated to dryness or near-dryness. May explode from heat, contamination or loss of temperature control.