nano zinc oxide particles in sunscreen

Remember the good old days when you could immediately tell if someone was using sunscreen? That white nose gave the hunky lifeguard away before you could even see his bright red pants.

Those days are over.

Now we have the technology to make zinc oxide and its BFF titanium dioxide – the rascals responsible for the white cast and chalky texture – so small, you won’t be able to see them sitting on your face.

Intrigued? Read on:

Why Should You Use Zinc Oxide?

Zinc oxide is one of the most effective UV filters out there. Here’s what makes it special:

  1. It provides broad spectrum protection ON ITS OWN: No more need to use four or five ingredients to be fully protected, yay!
  2. It’s very gentle on the skin: It’s one of the very few UV filters that won’t irritate even sensitive skin or cause allergies. Double yay!

But, the white cast and thick consistency are serious downers. It’s not unusual to get all excited about the gentleness of zinc oxide only to give it up for life when you realise how user-unfriendly it can be. Bummer!

Enter nanoparticles (aka microparticles), the new technology I was talking about…

Related: Why Zinc Oxide Is The Best UV Filter Ever


Is your sunscreen up to the job? Download your FREE “Sunscreen Audit” cheatsheet to find out if your sunscreen is both effective AND safe:


What Are Nanoparticles?

Nanoparticles are tiny particles. Duh!

Nanotechnology drastically shrinks the size of a substance so that it’s much, much smaller than its non-micronized original.

Of course, when something becomes that tiny, it also starts to behave differently. Micronized zinc oxide:

  • Doesn’t leave a white cast behind (those tiny molecules are practically invisible to the naked eye!).
  • Has a lightweight texture that makes it so easy to apply and comfortable to wear.

So easy and comfortable, the first time I used a sunscreen with zinc oxide nanoparticles, I almost didn’t believe it really had zinc oxide. It felt exactly like one of those lightweight Asian sunscreens we all love so much minus the potentially irritating synthetic UV filters and alcohol that give them their weightless textures.

The best of both worlds… Or not?

Are Zinc Nanoparticles Safe?

Here’s the deal: the smaller something is, the easier it can penetrate skin.

Zinc oxide is a pretty big molecule. But when you shrink it down to an invisible size, there’s a chance it can penetrate your skin, get into your bloodstream, and cause all sorts of problems.

IF it gets in there. But, does it?

Nope. Like all UV filters, zinc oxide needs to stay on the surface of the skin to protect it from the sun. If it penetrated your skin, then UV rays would get through too and cause all sorts of havoc. In other words, an UV filter that penetrates skin is useless.

That’s why cosmetic chemists often coat zinc oxide nanoparticles with silicones and other occlusive agents. This way, these nanoparticles stay where they should and are needed – on the surface of your skin.

The Real Danger: Nanoparticles in Spray Sunscreen

Nanoparticles can’t get in through your skin. Phew!

But, they can get in through your nose. When you apply spray suncreen, you’ll likely breathe some of those nanoparticles in. They end up in your lungs and may damage them.

So, stay away from spray sunscreens with nanoparticles.

And while you’re at it, stay away from all spray sunscreens, period. I know they’re very convenient to use, but it’s so hard to tell if you’ve missed a spot. Until that spot gets a bad sunburn. Ouch!

Related: Why I Don’t Use Spray Sunscreen (And You Shouldn’t Either)

The Bottom Line

If you’ve always wanted to jump on the zinc oxide bandwagon but were put off by the white cast and greasy texture, nanoparticles are the way to go. They’re safe. Just don’t get your dose from a spray sunscreen.