What zinc oxide actually is.
A mineral that's been in topical skincare for a hundred and fifty years. Particle size matters more than people realise.
Zinc oxide is a white mineral powder. It's produced when zinc metal burns in air — the result is a fine, chalky compound called ZnO. The first commercial use in topical skincare dates to the late 1800s, which means it's been studied for almost a hundred and fifty years. There aren't many ingredients in your bathroom cabinet with that kind of research record.
Particle size matters more than people realise. When formulators talk about 'nano' vs 'non-nano' zinc oxide, they're describing particle size. Nano means smaller than 100 nanometres — small enough that the particles could theoretically pass through gaps in skin. Non-nano means larger than 100 nm — too big to penetrate intact skin.
Research has been consistent for two decades: non-nano zinc stays at the surface of the stratum corneum, where it does its job. It doesn't enter the bloodstream. It doesn't accumulate in tissue.
We use a non-nano grade. We tested for particle size in every supplier sample before we picked one. The supplier we work with is USP pharmaceutical grade — the same purity tier that's used in topical drug products — and the zinc gets tested per batch for heavy-metal content, microbial content, and particle-size distribution. None of that is unusual for the industry; what's unusual is that most consumer brands don't talk about it.
Zinc oxide is a well-documented mineral with a long history in topical skin preparations going back over a century. It's the active ingredient in zinc-oxide diaper-rash creams that have been on pharmacy shelves since the 1890s. It's used in calamine lotion, in topical antiseptics, in barrier creams for skin conditions. Inclusion as a mineral skin-care ingredient predates a lot of the marketing categories that exist today.
Sunnbalm is called Sunnbalm because we like the name and the brand world is built around it. The connection between zinc oxide and outdoor skincare is well known. We don't make any claims about Sunnbalm's UV-protective performance — we make Sunnbalm, with zinc oxide, and trust customers to draw their own informed conclusions. We are a cosmetic skin balm.
A balm doesn't have to do everything for everyone. Most products in the market try to. Zinc has been in body care for a century — we kept it there.