Benzoyl peroxide

Benzoyl peroxide (CAS 94-36-0), also known as BPO and approved as E928 in food applications, is an organic peroxide used across industries as a free-radical initiator, bleaching agent, and curing catalyst. Its ability to generate reactive radicals on decomposition makes it a core processing chemical in polymer manufacturing, food treatment, and topical pharmaceutical formulations. In plastics and rubber, BPO initiates free-radical polymerization.

It facilitates the cross-linking of resins, silicones, and elastomers, directly influencing cure speed and final material properties. Food producers use it as a flour bleaching agent to accelerate the natural whitening of wheat flour. This process improves dough handling characteristics. In pharmaceutical manufacturing, it is the active ingredient in topical acne treatment formulations, where its antimicrobial oxidizing action targets acne-causing bacteria.

Personal care formulators also incorporate BPO into medicated creams and gels at controlled concentrations for the same antimicrobial function. Benzoyl peroxide is supplied as a white powder or granules. It is typically wetted or diluted with water or plasticizers to reduce explosion risk during handling and transport. Standard commercial grades include 70–75% active content (water-wetted) and 50% dispersions.

Pharmaceutical-grade material is available to USP and Ph.Eur. specifications for use in regulated drug product manufacturing. These standards ensure the highest purity for sensitive medical applications.