How do you solve a problem like zinc oxide?
This white mineral gently protects you from the entire UV spectrum but its thick, greasy texture feels SO uncomfortable on the skin. And don’t get me started on the white cast it leaves behind!
Zinc oxide is so annoying, it makes you want to cheat. You know nothing else comes even close to it but at least you don’t have to go around looking like Caspar all day.
Ditto for titanium dioxide, zinc oxide’s cousin. There must be a way to make them work.
What The Heck Is Nanotechnology?
To cut a long story short, nanotechnology takes one large particle, like zinc oxide, and makes it super small.
(Nano is short for nanometre. That’s one billionth of a metre or, in lay terms, about one thousandth of the thickness of hair).
Micronized zinc oxide and titanium dioxide behave differently. They’re as gentle and effective at fighting UV rays as ever but their new size makes them invisible to the naked eye. You know what that means? No more white cast! Yay!
Plus, their textures aren’t greasy anymore. You can pile on the layers without feeling like your skin is being suffocated.
What’s The Problem With Nanotechnology?
Sounds awesome, right?
Not according to its critics. Here’s the deal: we know that normal-sized zinc oxide and titanium dioxide are too big to penetrate the skin. They just sit on its surface, where they can’t cause any serious (think like cancer) side effects.
But, these much smaller sizes? Are they as harmless?
Well, some studies have found something worrying: these nanoparticles can produce free radicals, the molecules that damage DNA cells. Scary, right?
But, there’s a catch. They do this only when they penetrate past the outer dead layers of the skin and into the living cells.
This would also make them useless as sunscreens. UV filters must stay on top of the skin to work. How else could they stop those pesky UV rays from getting in and damaging your skin?
Can Nanoparticles Penetrate Skin?
Short answer: nope.
Current research is clear: nanoparticles remain on the surface and can’t reach the living cells.
But, if you’re really worried about free radicals, just use your sunscreen together with an antioxidant serum. That’ll destroy those free radicals before they can do any real harm.
The Real Problem With Nanoparticles
Topical application is safe. Inhalation is another matter entirely.
Studies done on rats show that, when inhaled, nanoparticles can damage animal lungs. I couldn’t find any studies on humans but, just to be on the safe side, don’t breathe this stuff in.
To recap: nano cream sunscreens = yay! nano spray sunscreens = no way!
The Bottom Line
Nanoparticles in sunscreens are safe. Just avoid the spray kind.
Have you ever used sunscreens with nanoparticles?