Yvonne BurkartPhD · toxicologist and low-tox consumer advocate
Use non-nano zinc oxide only, and avoid avobenzone, oxybenzone, octocrylene, homosalate, octisalate and octinoxate.
What it rests onPrecautionary reading of an absorption finding plus the regulatory gap: in her words, 'more data are needed to confirm the safety of these sunscreen chemicals yet they're still being sold to us'. She does not claim the trial demonstrated harm.
Source: dryvonneburkart.com ↗
Michelle WongPhD · chemist and science communicator
Absorption at these levels is not evidence of harm, and avoiding the filters has a cost of its own.
What it rests onDose reasoning plus a mechanism correction she makes elsewhere: only a fraction of a percent of most of these filters is absorbed, and receptor binding on its own 'doesn't tell us much about the risk of bad health effects', because compounds binding the same receptor can have opposite effects or none.
Source: labmuffin.com ↗
Burkart writes for families and repeatedly singles out children and pregnant women, the groups where an absorption finding carries the most weight and where the least outcome data exists. Wong is answering for a general adult using sunscreen daily. Neither is speaking about people at high skin-cancer risk, which is the population where the cost of using less sunscreen is highest and where reading only one of them would be a mistake.
Both agree the FDA studies found real absorption, both agree zinc oxide is safe and effective, and neither tells anyone to stop using sunscreen. Burkart pairs her advice with shade, hats and clothing; Wong's objection is to the inference from absorption to harm, not to mineral sunscreen.
Human outcome data on the absorbed filters at realistic use levels, or a toxicokinetic study establishing what those plasma concentrations mean rather than that they exist. Burkart's own framing points at this: she says more data are needed, so data is what would move her.
You do, and your call is dated, kept, and yours to change. Follow the people you already trust and what they publish turns into a short daily practice.
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