Every sunscreen sold in the US has to meet the FDA's bar for safety and effectiveness. But not every active ingredient has cleared that bar the same way — and the difference between mineral and chemical filters is bigger than most people realize. Here's what the actual research says, with sources, so you can make up your own mind.
What the FDA has and hasn't confirmed
In its 2019 proposed sunscreen rule, the FDA classified only two active ingredients as GRASE (Generally Recognized As Safe and Effective) without conditions: zinc oxide and titanium dioxide, the two mineral filters, at concentrations up to 25%. For the 12 most common chemical filters — including oxybenzone, avobenzone, octocrylene, homosalate, octisalate, and octinoxate — the FDA said it needed more safety data before it could make the same determination. That's not the same as saying they're dangerous. It means the data the FDA has on hand isn't yet enough to confirm they meet the same safety standard mineral filters already meet.
What the JAMA studies found
Two studies published in JAMA (2019 and 2020, led by Dr. Murali Matta at the FDA) tested how much of a chemical sunscreen's active ingredients end up in the bloodstream under normal, maximal-use conditions — the way people are actually told to apply sunscreen.
- 2019 study: avobenzone, oxybenzone, octocrylene, and ecamsule were all absorbed into the bloodstream at levels exceeding the FDA's own safety threshold of 0.5 ng/mL — after just a single application.
- 2020 follow-up study: tested six chemical filters (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, octinoxate) over four days of use. All six stayed above the 0.5 ng/mL threshold, and measurable levels were still detectable in participants' blood for days after they stopped applying it.
To be clear about what this does and doesn't mean: absorption into the bloodstream is not the same as proof of harm. The FDA's own Dr. Janet Woodcock has said as much publicly, and the study authors were explicit that their findings are not a reason to stop wearing sunscreen. What the studies do establish is that these ingredients get into your system at levels the FDA itself says should trigger further safety testing — testing that, as of the FDA's most recent guidance, still hasn't been completed for most chemical filters.
Why zinc oxide is different
Mineral filters work by an entirely different mechanism, which is why this entire category of question doesn't apply to them the same way. Zinc oxide sits on the surface of your skin and reflects and absorbs UV light there — it doesn't need to be absorbed into the body to work. That's also why dermatologists reach for it first for sensitive skin, reactive skin, rosacea, and post-procedure care, and why it's the standard first sunscreen recommended for infants and young children.
It's also photostable (it doesn't break down in sunlight the way avobenzone can) and it's the reef-safe standard, unlike oxybenzone and octinoxate, which are restricted in Hawaii and Key West over coral reef damage.
What this means for how we formulate
We built our Mineral Sunscreen SPF 50 PA+++ around 20% zinc oxide plus 5% titanium dioxide — both already FDA GRASE at those levels, with no chemical UV filters and nothing riding on data the FDA is still waiting for. A few things that come directly out of that choice:
- No systemic absorption question to answer. Zinc oxide and titanium dioxide stay on the skin's surface.
- Fragrance-free. Fragrance is one of the most common causes of sunscreen-related irritation, chemical filters aside — we left it out entirely.
- No white cast, including on deeper skin tones. The knock on mineral sunscreen used to be a chalky finish. Micronized zinc oxide in a lightweight, non-greasy base (squalane, hyaluronic acid, aloe) fixes that — see our full breakdown of how.
- Reef-safe by default. No oxybenzone, no octinoxate.
The honest bottom line
Dermatologists and the FDA agree on one thing without qualification: wearing sunscreen, of any FDA-approved kind, beats not wearing sunscreen when it comes to skin cancer and photoaging risk. Nobody credible is telling people to stop using chemical sunscreen. What the research does give you is a legitimate, well-documented reason to prefer mineral filters if you'd rather not have UV-filtering chemicals in your bloodstream at levels the FDA hasn't finished evaluating — which is exactly why we only formulate with zinc oxide and titanium dioxide.
Frequently asked questions
Does this mean chemical sunscreens are unsafe?
No credible health authority has concluded that. The studies show absorption above a regulatory threshold that triggers more testing — not confirmed harm. It's a legitimate open question, not a settled danger.
Is mineral sunscreen automatically better?
It sidesteps the systemic absorption question entirely, and it's gentler for sensitive and reactive skin. Whether that matters more to you than a chemical formula's lighter feel is a personal call — we just think you should get to make it with the actual data in front of you.
Where can I read the original studies?
Search "Matta sunscreen JAMA 2019" and "Matta sunscreen JAMA 2020" for the peer-reviewed papers, or the FDA's 2019 proposed sunscreen order for the GRASE determinations directly.