Benzoyl Peroxide

CAS #:  94-36-0

Synonyms: Dibenzoyl peroxide; benzoperoxide; benzoyl superoxide; BPO; Benzoic Acid, Peroxide;

Uses: Bleaching agent for flour, fats,oils, and waxes; polymerization catalyst; drying agent for unsaturated oils; pharmaceutial and cosmetic purposes; rubber vulcanization without sulfur; burnout agent for acetate yarns; production of cheese; embossing vinyl flooring (proprietary).

Hazard:   CONTACT WITH EYES OR SKIN: irritates eyes. Prolonged contact may irritate skin.  BENZOYL PEROXIDE is a white, odorless powder, moderately toxic. It is most dangerous when it contains less then 1% water. A moisture content of 3% allowed slow burning only, and at 5% ignition did not occur. Mixed with a large surplus of water (30% or more), it is relatively safe. In dry form, it is a very dangerous material. It will explode spontaneously when heated above melting point (103° C). An explosion which occurred when a screw-capped bottle of the peroxide was opened has been attributed to friction, which initiated a mixture of peroxide and organic dust in the cap threads. A violent explosion occurred during purification of the peroxide by Soxhlet extraction with hot chloroform. It is a powerful oxidizer, which ignites readily and burns rapidly. In contact with reducing agents, it may ignite by spontaneous chemical reaction. It must be kept in a cool place, in isolation and out of the sunlight or sources of heat. Also, avoid shock or friction. It reacts violently with inorganic or organic acids, alcohols, amines, metallic naphthenates and polymerization accelerators (e.g., N,N-dimethylaniline). Explosive or violent reaction upon contact with dimethyl sulfide, lithium aluminum hydride or aniline [Bretherick, 5th ed., 1995, p. 1140]. Mixture with carbon tetrachloride and ethylene explodes when exposed to heat. Ignition occurred upon contact with methyl methacrylate, polymerization of vinyl acetate in ethyl acetate accelerated out of control leading to ignition and explosion. At 50° C a mixture of dibenzoyl peroxide and charcoal reacts violently producing dense white smoke of benzoic acid, benzene, phenyls and carbon dioxide.