Nano vs Non-Nano Zinc Sunscreen: What That Label Really Certifies
Turn over a mineral sunscreen and there’s a decent chance you’ll find it printed near the SPF number: non-nano. It looks like a grade somebody awarded in a lab. So here’s a strange fact. The bodies that actually wrote down what “nano” means in a cosmetic, the European Commission, Australia’s TGA and the US FDA, were all answering a different question than that badge implies, and two of them published rulings on whether these particles get into your skin at all. Their answer doesn’t hand the win to either side. To find out what a non-nano zinc sunscreen really certifies, read what the regulators wrote, in the order they wrote it.
TL;DR: “Nano” is defined in EU law as roughly 1 to 100 nm [1], while the FDA says it has never set one [4]. EU law makes brands declare nano ingredients as [nano] in the ingredient list, and never defines or checks the opposite claim. On skin the rulings are awkward for the badge: the EU’s science committee found no indication that zinc oxide nanoparticles penetrate skin, and said in the same opinion that non-nano zinc isn’t of any additional safety concern compared with the nano form [2]. What does split the rulings is route of exposure, since both EU opinions carve out sprays [2], and the titanium dioxide one adds loose powders [5]. Read the format and the ingredient list, not the front.
Where “non-nano” on a sunscreen label came from
The word didn’t start as a marketing idea. It started as a disclosure rule pointing the other way.
The EU’s Cosmetics Regulation, the law any brand follows to sell a sunscreen in Europe, Korean brands included, has a very specific sentence about labelling: “All ingredients present in the form of nanomaterials shall be clearly indicated in the list of ingredients. The names of such ingredients shall be followed by the word ‘nano’ in brackets” [1]. That’s why you sometimes see Zinc Oxide [nano] in an ingredient list where everything else is plain text. It isn’t the brand being chatty, it’s a legal requirement.
The same law adds a paperwork step for nanomaterials in general, requiring notification to the Commission “six months prior to being placed on the market” [1]. Sunscreen filters fall outside that article, though: the same provision says it does not apply to nanomaterials used as colorants, UV filters or preservatives, which are handled under a separate route [1]. Nano zinc oxide and titanium dioxide get their clearance through the annex of approved filters instead, which is what the science opinions below are for.
Now notice what the rule does not do. It creates an obligation to declare nano. It never defines a “non-nano” claim, never sets a threshold you’d have to prove to make one, and never asks anyone to check it. The badge fills the space the law left empty, which is why it can be printed in a big friendly font while [nano] shows up in the small print of the ingredient list. One of those two words was written by a regulator, and it’s the small one.
So how small is nano? The numbers that are actually written down
Three regulators, three documents, and the answer is less unified than you’d hope.
The EU’s version is binding law. A nanomaterial is “an insoluble or biopersistant and intentionally manufactured material with one or more external dimensions, or an internal structure, on the scale from 1 to 100 nm” [1]. Note how much is packed in there besides size. It has to be insoluble or biopersistent, meaning it does not dissolve or break down once it’s there, and it has to be made that way on purpose. Australia’s TGA used the same window for its review of mineral sunscreens: “the definition of TiO2 and ZnO NPs includes materials within the nanosize range of 1 to 100 nm” [3]. Two agencies, one number, so far so tidy.
Then there’s the FDA, which is refreshingly blunt: “FDA has not established regulatory definitions of ‘nanotechnology,’ ‘nanomaterial,’ ‘nanoscale,’ or other related terms” [4]. Its 2014 guidance gives industry two questions instead. The first asks whether a material is engineered to have a dimension “in the nanoscale range (approximately 1 nm to 100 nm).” The second stretches much wider, covering size-dependent behaviour “even if these dimensions fall outside the nanoscale range, up to one micrometer (1,000 nm)” [4]. A micrometre is ten times the EU cutoff, so the same jar can fall inside one framework and outside the other.
And the number describes a powder, not the cream
Here’s the part that quietly undoes any single figure on a front label. What these minerals do inside a finished sunscreen isn’t a cloud of separate spheres. The TGA review says nanosized zinc oxide and titanium dioxide “exist in three separate states: primary particles (5-20 nm), aggregates (30-150 nm) and agglomerates (1-100 microns),” and adds the detail that matters: “Primary particles cluster together to form aggregates and are the smallest units present in a final sunscreen formulation” [3].
Read that twice. The smallest thing in the tube is the aggregate, and aggregates run from 30 to 150 nm, straddling the legal line in both directions. Even the EU’s science committee describes a safe grade as a spread rather than a point, clearing zinc oxide with “a median diameter (D50: 50% of the number below this diameter) of the particle number size distribution between 30 nm and 55 nm” [2]. In plain terms, half the particles are smaller than that and half are bigger. Particle size in a real formula is a distribution, and a one-word badge can’t carry one. It’s the same flattening we took apart in organic versus inorganic sunscreen.
What the agencies found when they went looking for skin penetration
This is the question the badge is implicitly answering, so the rulings are worth quoting rather than summarising.
The TGA reviewed the literature through August 2016 and published its conclusion in January 2017: “the current weight of evidence suggests that TiO2 and ZnO NPs do not reach viable skin cells (even in compromised skin) or the general circulation, but rather remain on the skin surface and in the outer layer of the stratum corneum, a surface layer of non-viable, keratinized cells.” Its verdict was that “neither TiO2 nor ZnO NPs are likely to cause harm when used as ingredients in sunscreens and when sunscreens are used as directed” [3].
The EU’s Scientific Committee on Consumer Safety got to the same place from a different direction. In its opinion on zinc oxide in nano form it wrote: “From the available information, there is no indication for penetration of ZnO nanoparticles through the skin.” Its clearance allows nano zinc oxide “at a concentration up to 25% as a UV-filter in sunscreens” and says it “can be considered not to pose a risk of adverse effects in humans after dermal application” [2].
Now the sentence that makes the badge awkward. The same opinion was also asked about ordinary, larger zinc oxide, and it put the two side by side: “Experimental evidence shows that both nano and non-nano particulate forms of ZnO are not absorbed through the skin.” The committee concluded that non-nano zinc oxide up to 25% “is safe and is not of any additional safety concern compared to the nano-forms assessed in this Opinion” [2].
That’s a tie, not a win. Both forms cleared, and neither was flagged as the safer one for skin. Picking non-nano to upgrade your protection against absorption buys you something the regulator already granted to both.
The variable the committee actually worried about wasn’t particle size at all. It flagged that a review “may be needed in the case of use of other specific coatings or specific absorption enhancers in the formulation, which can promote the dermal penetration of ZnO particles (nano or non-nano)” [2]. Note the bracket at the end. What surrounds the particle can matter more than how wide it is, and no front-of-pack claim covers that. The headlines about filters turning up in blood samples involved different chemistry entirely, which we covered in what the sunscreen absorption studies measured.
Sprays and loose powders, where the rulings really do split
Here’s the place the agencies genuinely drew a line, and it has nothing to do with the word on the front. Every clearance above was written for skin, and both EU opinions then set a second route aside. On zinc, the SCCS wrote that its conclusion “does not apply to other applications that might lead to inhalation exposure to ZnO nanoparticles (such as sprayable products),” and separately that “the use of ZnO nanoparticles in spray products cannot be considered safe” [2]. The parallel opinion on titanium dioxide says the committee “does not recommend the use of nano TiO2 in applications that would lead to any significant inhalation exposure (e.g. powder or sprayable products)” [5].
Read that as a boundary on where a clearance applies, not as a finding that your sunscreen is dangerous. Skin is one route into the body, lungs are another, and a committee that assessed the first didn’t extend its sign-off to the second. The TGA makes the mirror-image point, cautioning that many of the alarming animal results came “through exposure routes that are not relevant in the context of sunscreen use” [3]. Those studies fed, injected or piped the particles into animals at high doses, which is not what putting a cream on your face does. So format tells you more here than the size claim does:
| Format | What the EU opinions cover | What that means for you |
|---|---|---|
| Cream, lotion, stick, serum | Cleared for dermal use, nano and non-nano alike [2] | The size badge isn’t deciding anything here |
| Aerosol or pump spray | Outside the clearance [2] | Follow the FDA and AAD spray instructions: onto your hands first, never at your face |
| Loose or brush-on mineral powder | Named alongside sprays for titanium dioxide [5] | Tap it on with the same care, keeping it away from your face |
So what should you read on a non-nano zinc sunscreen label?
Three things, in descending order of how much they’re worth.
- The ingredient list, looking for [nano]. In any product made to EU rules that bracket is mandatory when it applies [1]. It’s the one piece of this subject a regulator forced onto the packaging.
- The format. Cream, stick and serum are what the EU opinions signed off on for skin; sprays are what both set aside [2], and loose powders are named in the titanium dioxide opinion [5]. You can see that difference from across the store.
- The front-of-pack claim, last. “Non-nano” isn’t tied to a definition you can check, the FDA hasn’t written one at all [4], and even where a number exists it describes the raw powder rather than the clusters in the finished cream [3].
None of this makes non-nano a con. Those grades give a heavier, more visible mineral finish, and picking one for that is a perfectly good reason. It just isn’t a safety upgrade, since the regulators put both forms on the same line. The badge does what the ocean-friendly wording does in our reef-safe sunscreen piece: a real technical idea, printed as reassurance, with nobody checking it.
The last word belongs to the agency that read the most papers on this. The TGA concluded that “the minor risks potentially associated with NPs in sunscreens are vastly outweighed by the benefits that NP-containing sunscreens afford against skin damage and, importantly, skin cancer” [3]. The American Academy of Dermatology puts the practical version in one line: “The best type of sunscreen is the one you will use again and again” [6]. Pick the mineral texture you’ll actually wear, and our complete Korean sunscreen guide has the wider tour of how the filters differ.
FAQ
Is non-nano zinc sunscreen safer than nano?
Not according to the regulator that assessed both. The EU’s Scientific Committee on Consumer Safety stated that experimental evidence shows both nano and non-nano particulate forms of zinc oxide are not absorbed through the skin, and concluded that non-nano zinc oxide up to 25% is not of any additional safety concern compared with the nano forms it assessed. Australia’s TGA agreed, finding these particles stay on the skin surface and in the outer layer of the stratum corneum rather than reaching living cells.
What size counts as nano in a sunscreen?
Under EU cosmetics law a nanomaterial is an insoluble or biopersistent, intentionally manufactured material with a dimension on the scale from 1 to 100 nm, and Australia’s TGA uses the same 1 to 100 nm window. The FDA has not established regulatory definitions of these terms at all, and its guidance also asks about size-dependent behaviour up to one micrometre, which is ten times wider than the EU line.
Is the term non-nano regulated on a sunscreen label?
No. EU law works in the other direction: it requires ingredients present as nanomaterials to be listed with the word nano in brackets, so you may see Zinc Oxide [nano] in an ingredient list. Nothing in that rule defines a non-nano claim or requires anyone to verify one, which is why the bracket in the ingredient list is worth more than the badge on the front.
Are mineral sunscreen sprays and loose powders a different question?
Yes, and this is the one place the rulings split. The EU opinions cleared these minerals for use on skin but excluded applications that could lead to inhalation exposure, naming sprayable products for zinc oxide and powder or sprayable products for titanium dioxide. That is a limit on where the clearance applies rather than a finding of harm, so the practical response follows the agencies’ own spray instructions, which we set out in our sun spray guide: onto your hands first, never aimed at your face.
Sources
The law (EU, read 2026-07-25):
[1] Regulation (EC) No 1223/2009 on cosmetic products, European Commission (Article 2(1)(k) definition of nanomaterial, “insoluble or biopersistant and intentionally manufactured material… on the scale from 1 to 100 nm”; Article 19(1)(g) “The names of such ingredients shall be followed by the word ‘nano’ in brackets”; Article 16(3) notification “six months prior to being placed on the market”; Article 16(2) carve-out: the article’s provisions “do not apply to nanomaterials used as colorants, UV-filters or preservatives regulated under Article 14”): link
The rulings (EU scientific committee opinions, full PDFs read 2026-07-25):
[2] SCCS/1489/12, Opinion on Zinc oxide (nano form), revision of 11 December 2012 (“no indication for penetration of ZnO nanoparticles through the skin”; cleared up to 25% as a UV-filter, “can be considered not to pose a risk of adverse effects in humans after dermal application”; “both nano and non-nano particulate forms of ZnO are not absorbed through the skin”; non-nano “not of any additional safety concern”; D50 between 30 nm and 55 nm; coatings and absorption enhancers may need re-evaluation; “the use of ZnO nanoparticles in spray products cannot be considered safe”): link
[5] SCCS/1516/13, Opinion on Titanium Dioxide (nano form), revision of 22 April 2014 (“the SCCS does not recommend the use of nano TiO2 in applications that would lead to any significant inhalation exposure (e.g. powder or sprayable products)”): link
The reviews (Australia and the US, read 2026-07-25):
[3] Literature review on the safety of titanium dioxide and zinc oxide nanoparticles in sunscreens, Therapeutic Goods Administration, published 11 January 2017 (nanosize range of 1 to 100 nm; primary particles 5-20 nm, aggregates 30-150 nm, agglomerates 1-100 microns, aggregates “the smallest units present in a final sunscreen formulation”; particles “do not reach viable skin cells… but rather remain on the skin surface and in the outer layer of the stratum corneum”; “neither TiO2 nor ZnO NPs are likely to cause harm when used as ingredients in sunscreens”; risks “vastly outweighed by the benefits”): link
[4] Considering Whether an FDA-Regulated Product Involves the Application of Nanotechnology, US Food and Drug Administration guidance, June 2014, docket FDA-2010-D-0530 (“FDA has not established regulatory definitions of ‘nanotechnology,’ ‘nanomaterial,’ ‘nanoscale,’ or other related terms”; Point 1, “the nanoscale range (approximately 1 nm to 100 nm)”; Point 2, dimension-dependent properties “up to one micrometer (1,000 nm)”): link
Dermatology guidance:
[6] Sunscreen FAQs, American Academy of Dermatology (“Sunscreen use can help prevent skin cancer by protecting you from the sun’s harmful ultraviolet (UV) rays”; “The best type of sunscreen is the one you will use again and again”): link
