Mineral or Chemical? The Honest Version
The FDA classified most chemical filters as not GRASE. What that means, what it does not mean, and why the wrong conclusion is worse than either filter.
If you have spent any time reading about sunscreen lately, you have probably emerged more anxious than informed.
One camp tells you chemical filters end up in your bloodstream and the FDA will not vouch for them. The other tells you the entire panic was manufactured to sell zinc oxide. Both are quoting real facts, which is why the argument never resolves.
Here is what happened, what it means, and what to do on a Tuesday morning.
What the FDA did
In 2019 and 2020, the agency ran studies measuring how much sunscreen ends up in the bloodstream after normal use. Six common chemical filters, among them oxybenzone, homosalate, octisalate, octocrylene, avobenzone and octinoxate, were detected in blood above the agency's screening threshold of 0.5 nanograms per millilitre.
Of the sixteen active ingredients the FDA reviewed, it proposed that only two be classified GRASE, meaning generally recognised as safe and effective: zinc oxide and titanium dioxide, both mineral, at up to twenty-five percent. Two others, PABA and trolamine salicylate, were proposed as not GRASE on safety grounds. The remaining twelve, including all the common chemical filters, were proposed as not GRASE because additional data is needed.
The headlines wrote themselves, and an entire category of marketing has been built on top of them.
One structural detail almost never survives the retelling. This sits in a proposed order, issued in 2021 under the CARES Act, which has still not been finalised. The proposed changes remain under review, and every one of those ingredients remains legally on sale in the meantime.
What that classification means
Considerably less than it sounds, and this is the part that rarely survives the headline.
The 0.5 figure marks the level at which the FDA decides an ingredient warrants further study, rather than a danger threshold. Detection above it triggers research rather than a warning.
Not GRASE does not mean unsafe. The FDA's own fact sheet is explicit that for these ingredients it has identified additional data which, if provided, might establish that sunscreens containing them are GRASE. The agency never recommended anyone stop using them, and the filters remain on the market while manufacturers supply what has been requested.
Absorption and harm are different things, and conflating them is arguably the single largest misunderstanding driving the anxiety. Chemical filters have been in use for decades without clear evidence of systemic harm, and millions of people apply them daily. What we lack is comprehensive long-term data on daily use across many years, which is precisely the gap the FDA identified.
Where the concerns are real
Two ingredients attract more scrutiny than the rest.
Oxybenzone shows the highest absorption of the approved filters and appears in urine samples. A 2023 review of 254 studies found mounting evidence of endocrine-disrupting properties at doses typical of sunscreen use, with reproductive effects flagged as the principal concern. It has also been banned in Hawaii and Key West over coral reef damage.
In 2024, the European Commission stated it could not determine the safety of current octinoxate use levels, citing endocrine disruption and genotoxicity.
The caveat that belongs with both: much of this evidence comes from laboratory and animal work. Human studies confirming meaningful harm remain limited. These findings were robust enough to trigger regulatory review, which is a different thing from establishing that anyone has been hurt.
The case for mineral
From a regulatory standpoint, mineral filters hold the strongest position available.
Zinc oxide and titanium dioxide are the only two of sixteen evaluated active ingredients proposed for GRASE status. They work at the surface without meaningfully entering the bloodstream, they are well tolerated by sensitive skin, they are considered appropriate in pregnancy and for young children, and they are more photostable than most chemical filters, breaking down less in sunlight.
For some women, mineral is genuinely the better default: during pregnancy or breastfeeding, on reactive or sensitised skin, with rosacea, and on skin recovering from a procedure.
The drawbacks are equally real. White cast remains the commonest complaint. Mineral formulations tend to feel heavier and blend less willingly, though formulations have improved substantially and many modern zinc products leave almost no residue.
The case against panicking
Here is the sentence that ought to settle most of this.
If you will not wear a mineral sunscreen because of how it looks or feels, and you therefore wear nothing at all, you are materially worse off than a woman using a well-formulated chemical product every single day.
That framing comes from a dermatologist and it is the correct one. The risk of ultraviolet damage is established, measured and enormous. The risk from absorption is theoretical and unquantified. Trading a certain benefit for an uncertain worry is a poor exchange.
The best sunscreen remains the one you will put on.
What to look for
Broad-spectrum, or the UVA logo. SPF measures protection against burning, which is UVB. UVA is what drives visible ageing, and it passes through window glass. In Europe, look for the UVA logo inside a circle, indicating UVA protection of at least a third of the SPF figure.
SPF 30 or above, applied properly. Most people apply a quarter to a half of the quantity used in testing, which means an SPF 50 applied thinly performs closer to an SPF 15. Quantity matters more than the number on the bottle.
A texture you will tolerate daily, which is a genuine selection criterion rather than a compromise, because adherence is the variable that determines the outcome.
And if you want to avoid the flagged ingredients specifically, oxybenzone and octinoxate are the two under most scrutiny. Skipping those while using other filters is a perfectly reasonable middle position.
Where this belongs
Under Renew, and it is the highest-return item in the entire framework.
Most visible ageing on exposed skin traces back to ultraviolet exposure, and most of a lifetime dose arrives incidentally rather than on holidays: through the car window, at a desk, walking between buildings, on grey days. It never registers as sun exposure, which is exactly why it accumulates unchallenged.
Which makes sunscreen the one item on this list where consistency beats optimisation by an enormous margin. A mediocre sunscreen worn every day outperforms an excellent one worn on holiday, and the gap is not close.
Which is why the mineral versus chemical debate, however diverting, is a second-order question. The first-order question is whether you put anything on this morning.
FAQ
Did the FDA say chemical sunscreens are unsafe?
No. It said most filters are not yet classified as generally recognised as safe and effective, which reflects missing data rather than demonstrated harm.
Is mineral sunscreen better?
Mineral is the sensible default during pregnancy or breastfeeding and on reactive skin. Speak to your doctor about any specific concern in pregnancy.
What is the wrong conclusion to draw?
Wearing less sunscreen. Ultraviolet exposure is the best established driver of visible facial ageing, so any filter you will use daily beats the one you avoid.
References
- FDA fact sheet on the proposed sunscreen order, listing which ingredients are proposed GRASE, which are not, and on what grounds.
- Sunscreen Drug Products for Over-the-Counter Human Use, FDA, the underlying rulemaking document.
- FDA Voices: the 2021 proposed sunscreen order has not yet been finalized. Confirms the proposed changes remain under review.
- The trouble with ingredients in sunscreen, Environmental Working Group. An advocacy organisation whose position is more cautious than the regulatory consensus; included so readers can see both sides.