Why Zinc Oxide Still Sets the Standard for Safe Broad-Spectrum Sun Protection
When people ask what is the best mineral sunscreen ingredient, zinc oxide is always the answer.
At Burnd, this is something we have believed for decades. In the early 1990s, burnd’s cofounder, Dr. Mark Mitchnick, developed and patented a form of transparent zinc oxide that could go on transparent while still delivering strong sun protection. He and two coauthors later published that work in a peer-reviewed paper in the Journal of the American Academy of Dermatology, showing that microfine zinc oxide provided broad-spectrum sunscreen protection, including long-wave UVA protection in the UVA I range, while also remaining a photostable sunscreen ingredient and nonreactive in sunscreen formulas.
That matters because sunscreen should do more than help prevent sunburn. Daily UV exposure includes UVA, and UVA is partially responsible for photoaging and other long-term skin damage. In our view, that is why broad-spectrum protection matters so much and why zinc oxide continues to play such an important role in mineral sunscreen.
What the research found
In Dr. Mitchnick’s paper, they looked at the qualities that really matter in a sunscreen ingredient: how well it protects across the UV spectrum, whether it contributes to SPF, whether it stays stable in sunlight, and whether it reacts with other sunscreen actives.The results were clear. Microfine zinc oxide provided protection across both UVA and UVB, including the long-wave UVA I range. It also stayed stable under UV exposure and did not speed up the breakdown of the organic sunscreens in the tested formulas, reinforcing its value in zinc oxide sunscreen formulations.
Why zinc oxide stands apart
Not all mineral sunscreen ingredients perform the same way. The paper showed that zinc oxide and titanium dioxide should not be treated as interchangeable.Microfine titanium dioxide can work well in UVB and part of UVA, but zinc oxide performed better in the longer UVA I wavelengths above 340 nm. It was also noted that zinc oxide was easier to use in transparent products, because it could appear much less white in thin films when the particle size was small enough.
Why this still matters today
For us at Burnd, this research helped shape how we think about sunscreen from the beginning. The goal is not just to check a regulatory box or put a trendy ingredient on a label. The goal is to use ingredients that provide real-world broad-spectrum protection, remain stable in use, and have a strong history of safe topical application.That is why zinc oxide still the OG. It is not just a familiar mineral sunscreen ingredient. It remains one of the most important tools for building sunscreens that protect skin from both immediate and long-term UV damage.
