Zinc Oxide

酸化亜鉛

What It Does

A mineral UV filter that provides broad spectrum protection by reflecting UV rays. Gentle on sensitive skin.

Zinc oxide is a mineral (inorganic) UV filter that provides broad-spectrum protection against both UVA and UVB rays. It sits on the skin surface and physically blocks, reflects, and scatters UV radiation. Zinc oxide is considered one of the safest and most effective sunscreen ingredients, approved for use even on babies and sensitive skin.

Traditional zinc oxide left a white cast on skin due to large particle sizes. Modern formulations use micronized or nano zinc oxide for improved cosmetic elegance, though some white cast may remain depending on particle size and concentration. Nano zinc oxide does not penetrate healthy skin and is considered safe, though there is ongoing research on potential environmental impacts.

Japanese sunscreens often combine zinc oxide with other UV filters (both mineral and chemical) to achieve high SPF and PA ratings while maintaining lightweight textures. Brands like Anessa, Allie, and Biore use sophisticated formulations to minimize white cast while maximizing protection.

How It Works

Mineral particles sit on skin surface and physically block, reflect, and scatter UV radiation. Provides immediate protection upon application.

The Japanese Context

Widely used in Japanese sunscreens, often combined with chemical filters. Japanese formulations minimize white cast through particle size optimization.