Glossary
White cast
The pale film some sunscreens leave. A comfort problem, and a real reason people stop wearing SPF.
White cast is the pale or grey film a sunscreen can leave on skin. It comes from mineral filters — zinc oxide and titanium dioxide — which work by sitting on the surface, and it shows far more on deeper skin tones.
It is not a safety issue. It is a comfort issue, and comfort decides whether sunscreen gets worn, which makes it the most practically important thing about a formula for many people here.
How to avoid it:
- Tinted mineral sunscreens add iron oxides that cancel the cast, and the tint has a second benefit: iron oxides give some protection against visible light, which matters for melasma. - Chemical filters absorb rather than sit on top and leave no cast at all. Modern Korean, Japanese and European filters are light and comfortable. - Hybrid formulas use both.
If a sunscreen leaves a cast you dislike, change the sunscreen rather than using less of it. Applying a thin layer to avoid the cast gives you a fraction of the stated protection, which is the worst of both outcomes.
See also
This article is general information, not medical advice. Skincare products are not medicines. Speak to a dermatologist about persistent or worsening skin conditions.