Zinc oxide

Zinc oxide (CAS 1314-13-2), abbreviated ZnO, is an inorganic mineral compound used in rubber, coatings, and personal care manufacturing.

Where is Zinc oxide used?

• Rubber and elastomer manufacturing: vulcanization activator
• Coatings and paint: white pigment and mildew-resistant additive for exterior architectural and marine coatings
• Personal care: UV-blocking and skin-protective agent in sunscreens, barrier creams, and mineral foundations
• Textile and leather processing: antimicrobial surface treatment that imparts preservation properties.
• Ceramics and glass: reduces cracking and improves opacity.
• Catalyst in organic syntheses such as methanol production.
• UV absorber in plastics and flame retardant.
• Desulfurizing gases.
• Chemical industry: raw material for manufacturing zinc-based products.

Good to know: Indirect process (French process) grades are typically preferred for rubber and higher-purity applications; direct process (American process) grades are also commercially available.

Formulation notes

• Contains approximately 78% zinc.
• Incompatible with magnesium and strong acids.

Typical specification

• Standard production from zinc vapour yields microparticles typically a few micrometres in size.
• Produced by direct and indirect processes; the direct process uses zinc-containing ores and yields less pure zinc oxide than the indirect process, which uses zinc metal of 92–99.995% purity.
• Nanoparticles are particles between one and one hundred nanometres in at least one dimension.

Regulatory status

• No sprayable sunscreen composed of zinc oxide nanoparticles should be available for sale in Europe.
• Not subject to restriction under EU REACH.
• Not identified as a substance of very high concern (SVHC) in the EU.

Storage, packaging and handling

• Should be stored in cool, dry, and well-ventilated areas.
• Must be protected from moisture.

Frequently asked questions about Zinc oxide

What purity can be achieved with the indirect process?

The indirect process uses very pure primary metallic zinc (SHG) as feed material to achieve the highest possible zinc oxide purity.

What are the regulatory requirements for zinc oxide in food contact plastics in the EU?

Regulation (EU) No 10/2011 states that plastic materials and articles intended to come into contact with foodstuffs must not release more than 25 mg Zn per kg of foodstuff. Zinc oxide, zinc sulfide, and zinc hydroxide are authorized as additives or polymer production aids but are prohibited as monomers or starting substances in food contact plastics.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.