Hydroquinone

Hydroquinone (CAS 123-31-9), commonly abbreviated as HQ, is an aromatic diol used industrially as a polymerization inhibitor, antioxidant, and chemical intermediate.

Where is Hydroquinone used?

• Photographic and printing chemistry: developing agent that reduces silver halide to metallic silver, controlling image density and contrast
• Rubber and polymer manufacturing: added to acrylic and vinyl monomers during production and transport to suppress unwanted polymerization
• Pharmaceutical intermediate: supports synthesis of active compounds
• Personal care: depigmentation products where it inhibits melanin synthesis, subject to regional regulatory limits
• It prevents premature crosslinking in reactive monomers and protects unstable materials during storage.

Good to know: Personal care use is subject to regional regulatory limits. USP and BP grades meet compendial requirements for pharmaceutical and cosmetic applications.

Commercial specifications

• Technical grade typically packaged in fiber drums or multi-wall bags