Zinc Oxide

Zinc oxide is the most complete mineral UV filter: it covers the entire UVB range and, uniquely among common filters, stretches across UVA-II and deep into UVA-I up to ~400 nm — true broad-spectrum protection from a single ingredient. It sits mainly on the skin surface, reflects and scatters light (plus some absorption), is photostable, and is the least sensitising filter available, making it the standard for children, rosacea, and post-procedure skin. Modern micronised and coated grades avoid the chalky white cast of the past. At 15–25% it anchors most mineral sunscreens. Slight dryness is its main drawback — moisturise underneath.