Should you stay away from nanoparticles in sunscreen?
Critics say that zinc oxide nanoparticles are so small, they’ll penetrate your skin and give you all kinds of nasty diseases – like cancer.
The panic got so out of hand, the few brands that had started using this technology quickly backtracked. Now you’ll more easily find a needle in a haystack than a nano-based sunscreen at Sephora.
It’s a shame because science says they’re not as bad as they’re made out to be. Plus, they have a few properties that make these sunscreens more pleasant to use.
Here’s the truth about nanoparticles in sunscreen:
What Are Nanoparticles??
Nanoparticles are very, very, very tiny (less than 1000 nanometers thick) particles of a substance. Nano is short for nanometre. That’s one billionth of a metre or, in lay terms, about one thousandth of the thickness of hair. That’s how small these particles are.
While nanoparticles can occur naturally (think minuscule droplets of sea spray), those in your sunscreens are man-made. To cut a long story short, nanotechnology takes zinc oxide and titanium dioxide, two large particles, and makes them super small.
No wonder people are scared these molecules can get through the skin, infiltrate the blood stream, and make you sick!
Zinc oxide and Titanium dioxide nanoparticles first became available in sunscreens in the 1980s, became popular in the 90s, got a bad reputation in the 00s and are just now starting to make their way back into your skincare products.
How do you know if your sunscreens contain nanoparticles? Look for the words “nano” or “micronised” on the bottle.
Benefits Of Nanoparticles In Sunscreen
Ever wondered why so many sunscreens are so thick and greasy?
Blame it on Titanium Dioxide and Zinc Oxide. These white minerals protect you from both UVA and UVB rays without irritating your skin.
But their unpleasant texture leave a greasy sheen all over your skin…. and a white cast that makes you look like Caspar The Ghost. Ugh.
Enter nanotechnology.
By making Titanium Dioxide and Zinc Oxide much smaller, they literally become invisible. 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.
Related: Is Zinc Oxide The Best UV Filter Ever?
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Are Nanoparticles In Sunscreen Dangerous?
Nanoparticles in sunscreen sound 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?
(Before you get too scared, even metabolic processes like breathing create free radicals – and you can’t stop breathing. The goal isn’t to get rid of free radicals completely. The goal is to reduce their negative impact as much as possible).
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 of the skin 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.
FYI, you should use your sunscreen with an antioxidant serum anyway. I always apply my Vitamin C serum before sunscreen. Why?
The truth is, even SPF 100 lets 1% of UV rays get through the skin – and that 1% generates free radicals. By using an antioxidant serums you’re counteracting that damage. Smart.
Don’t take just my work for it. A study published in the Nanotechnology, Science and Applications Journal has found that “Given the growing commercial and scientific interest in the use of nanosized TiO2 and ZnO in sunscreens, this paper highlights the effectiveness and safety of NP sunscreen formulations.”
Related: What Are The Best Antioxidant Serums?
The Real Problem With Nanoparticles In Sunscreen
Topical application of nonaparticles 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.
I’m already avoiding spray sunscreens for another reason. You don’t see it, so it’s much harder to create an even layer of protection on your skin.
To recap: nano cream sunscreens = yay! Nano spray sunscreens = no way!
The Bottom Line
Nanoparticles in sunscreens are safe. If you’re concerned about nanoparticles, just avoid spray sunscreens or opt for other formulas with synthetic filters that don’t leave you look like Caspar The Ghost.
I went to a seminar during my first year in grad school and a guy gave a speech about nanoparticles and fishes. Apparently, some fishes get tumors when exposed to man-made nanoparticles in the water. The sunscreen I use still has a white cast and it’s a lifesaver to me since chemical sunscreens give me big breakouts.
Even if antioxidants are added to reverse the oxidizing properties of sunscreen, wouldn’t the exposure to sunlight immediately break down any antioxidants, assuming that they are stable in the first place?
Danielle, totally an great question! They do break down. They do, however help to offset the damage. At least they don’t break down as fast as they would if you didn’t have sunscreen. This is one reason why you should wear an antioxidant serum underneath your sunscreen. To put it in a nutshell; antioxidant in sunscreen simply aren’t enough!
My flippant reaction is that nanotechnology sounds awesome and reminds me of nanites from Stargate. Of course, the nanites were actually pretty bad.
If they can create free radicals, it seems a wee bit daft to me, considering that the sun is one of the primary causes of free radicals and thus one of the reasons why we use sunscreen.
Personally, I wouldn’t mind having a white cast. I’m already milk-colour, I welcome pale.
nano techonology is so popular in the far east here. everything with nano suddently seems to be better. personally, i am very wary about it. i’d rather have a white cast instead.
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gio this is so enlightening. all the while i thought everything with nano technology has to be better in terms of penetrating deeper into skin and repair or protect. in tht case i agree with jojoba, i wouldn’t mind a white cast on my face then.
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Dao: I read a study about that too. Apparently fishes exposed to nanoparticles developed brain tumors. I don’t think it was Titanium Dioxide or Zinc Oxide, though. So far, these have been proved to be safe when applied topically on healthy skin, but ingestion and inhalation is dangerous. But like you, I prefer physical sunscreens and don’t really care about the white cast, my skin is white (litterally) anyway.
Danielle: that’s a good point. Antioxidants degrade when exposed to sunlight, not sure if that happens immediately but very rapidly, yes. Since sunscreens are supposed to be reapplied frequently anyway I wouldn’t worry too much about it. Nanoparticles can’t penetrate the skin so even if antioxidants weren’t added I doubt they would generate free radicals.
Anastasia: lol, I had to google that, I’m not a Stargate fan unlike my mom. She has never missed an episode. But they sound pretty nasty.
I know, it sounds silly to me but since nanoparticles can’t penetrate skin, I don’t think that would be a problem. I’m more concerned about chemical sunscreens that are said to generate free radicals too and that’s why I tend to avoid them. I stick to Zinc Oxide and Titanium Dioxide as they are the best sunscreen ingredients available at the moment and I don’t mind the white cast either. Kinda matches my skin anyway.
Jojoba: I agree with you. Although topical application is supposed to be safe, and is definitely safer that not wearing sunscreen or using one that doesn’t offer broad spectrum protection, these particles haven’t been studied much and some concern about their safety (esp regarding inhalation) remain. Based on current research, I wouldn’t avoid sunscreens with nanoparticles, but I’d still I’d rather stick to physical sunscreen that don’t contain them as they are a better option.
prettybeautiful: that is a very common misconception. But actually these particles can’t penetrate skin (most ingredients used in beauty products can’t, doesn’t matter what marketing says) and in any case, you wouldn’t want them too. In order to protect the skin from the sun rays, these ingredients have to remain on the surface. I don’t mind the white cast either, being properly protected is more important.