Zinc Oxide: The Original Broad-Spectrum Filter
The mineral workhorse, fully explained.
Zinc oxide and titanium dioxide are the only two UV filters the FDA proposed as GRASE (generally recognized as safe and effective), and zinc oxide alone covers both UVA and UVB.
Dermatologists describe zinc oxide as the original broad-spectrum filter: it's photostable, gentle enough for reactive skin, and the trade-off is the white cast that comes from scattering visible light.
Questions we get a lot
Why is zinc oxide considered broad-spectrum on its own?
Zinc oxide absorbs and scatters across both the UVA and UVB range, so a single ingredient can protect against burning UVB and deeper, aging UVA. That's unusual — most organic filters cover only part of the spectrum — which is why zinc oxide is often called the original broad-spectrum filter.
Why does zinc oxide leave a white cast?
Zinc oxide scatters visible light, not just UV, leaving a whitish film — and the effect is stronger at higher concentrations and on deeper skin tones. Finely milled or 'micronized' zinc, and tinted formulas with iron oxides, reduce the cast while keeping the broad-spectrum protection.
Is zinc oxide a safe and approved sunscreen filter?
Yes. Zinc oxide is one of only two UV filters (with titanium dioxide) the FDA proposed as GRASE — generally recognized as safe and effective. It's photostable and widely used in Europe and Asia too, where it appears on regulatory UV-filter lists, and it's a common choice for sensitive and pediatric skin.
r/AsianBeauty: 'Why does my zinc oxide sunscreen leave such a strong white cast?'