Benzoyl peroxide (BPO), with the chemical formula ​​C₁₄H₁₀O₄​​ and ​​CAS number 94-36-0​​, is a vital organic peroxide widely used in industrial and chemical processes. This white crystalline powder, characterized by a faint almond-like odor, serves as a powerful oxidizing agent, initiator, and crosslinking agent across diverse sectors.

🔬 ​​Chemical and Physical Properties​​

​​Molecular Weight​​: 242.23 g/mol

​​Melting Point​​: 105°C (decomposes explosively above this point)

​​Density​​: 1.334 g/cm³

​​Solubility​​:

Highly soluble in acetone, chloroform, and benzene

Slightly soluble in ethanol and methanol

Negligible solubility in water

​​Reactivity​​: Extremely unstable when dry. Sensitive to heat, friction, impact, and contaminants. Reacts violently with strong acids, bases, reducing agents, and metals.

​​Safety Note​​: Commercial BPO is stabilized with 25–30% water to mitigate explosion risks during storage and transport.

⚙️ ​​Key Industrial Applications​​

1. ​​Polymerization Initiator​​

BPO is the primary free-radical initiator for synthesizing polymers like:

​​PVC​​, ​​polyacrylonitrile​​, and ​​acrylate resins​​

​​Unsaturated polyesters​​ and organic glass adhesives

Its decomposition into reactive radicals (around 70–90°C) drives chain-growth polymerization.

2. ​​Crosslinking Agent​​

​​Rubber Vulcanization​​: Accelerates curing in silicone and fluorocarbon rubbers, enhancing elasticity and durability.

​​Polyethylene Modification​​: Improves thermal stability and mechanical strength.

3. ​​Bleaching and Oxidation​​

Historically used to bleach ​​flours​​, ​​oils​​, and ​​waxes​​. Banned in food (e.g., EU, China since 2011) due to toxicity concerns.

​​Non-Food Uses​​: Cosmetic formulations, textile whitening, and organic wastewater treatment.

4. ​​Pharmaceutical and Chemical Synthesis​​

Intermediate in manufacturing ​​antibiotics​​ (e.g., penicillin) and dermatological treatments (acne gels).

Catalyst for dye synthesis and high-performance coatings.

⚠️ ​​Safety and Handling Protocols​​

​​Hazards​​:

Classified as ​​UN 3108​​ (5.2 Organic Peroxide).

Acute toxicity (Rat oral LD₅₀: 7,710 mg/kg).

Skin/eye irritant; may cause sensitization.

​​Storage​​: Keep at 2–25°C in ventilated, non-reactive containers. Avoid light, heat, and contamination.

​​Fire Response​​: Use water spray, foam, or CO₂. ​​Never use sand​​ (explosion risk).

♻️ ​​Environmental and Regulatory Status​​

​​Ecotoxicity​​: Moderate aerobic/anaerobic biodegradability. Potential bioaccumulation (BCF: 250).

​​Regulations​​:

Listed in WHO IARC Group 3 (not carcinogenic to humans).

Banned in food additives globally; restricted under REACH for consumer products.

🔮 ​​Future Outlook​​

Research focuses on:

​​Safer Alternatives​​: Encapsulated BPO for controlled-release applications.

​​Environmental Remediation​​: Advanced oxidation processes for pollutant degradation.

​​Benzoyl peroxide (CAS 94-36-0)​​ remains indispensable in polymer science and specialty chemistry, though its use demands rigorous safety protocols. As industries prioritize sustainability, innovations in BPO delivery systems and eco-friendly applications will shape its future role.