New Research on Chemical Sunscreen Filters — Why We Formulate With Mineral Zinc Oxide

A new study out this month has put a spotlight on two of the most common chemical UV filters used in sunscreen, homosalate and oxybenzone, and the findings are worth talking about, especially if you're slathering sunscreen on kids every day (as you should be).

What the study found

German researchers, publishing through the American Chemical Society, tested urine samples from roughly 18,700 people collected over more than a decade, the vast majority from Queensland. The results were striking: almost all of the children in the study showed elevated levels of homosalate, with 80% exceeding the threshold Germany's own health authorities use to flag a risk of adverse effects, and just over half exceeding the threshold for requiring active intervention.

Homosalate and oxybenzone are both classified as potential endocrine disruptors, meaning they may interfere with the body's hormone systems. Australia's Therapeutic Goods Administration flagged concerns about both ingredients last year, recommending manufacturers using them add extra safeguards, though the TGA has stopped short of confirming a direct causal link in humans. The European Union has taken a firmer stance, capping homosalate at less than half the concentration still permitted in Australia, the US and Canada.

Kids are particularly exposed. Researchers pointed to lip products, hand-to-mouth contact, and eating with sunscreen-covered hands as extra pathways for these chemicals to end up somewhere they're not meant to be.

Why this matters for how we formulate

This is exactly the reasoning behind our decision to build MOTHER SPF around mineral filters — zinc oxide — rather than chemical UV filters like homosalate or oxybenzone. Mineral filters work by sitting on the surface of the skin and physically reflecting UV radiation, rather than being absorbed into the bloodstream, which is the mechanism behind the concerns this study raises.

We're not going to tell you every mineral sunscreen on the market is automatically the safer choice, formulation quality varies brand to brand so you need to do your own research. But when we sat down to build MOTHER SPF, avoiding homosalate and oxybenzone entirely was a non-negotiable starting point, that we have always maintained.

What you can do today

• Check the active ingredients list on your family's current sunscreen, homosalate and oxybenzone will be listed by name.
• Look for zinc oxide as the active ingredient if you'd rather avoid chemical UV filters altogether.
• Reapply regardless of formula, filter type doesn't change the two-hourly reapplication rule.

If you want to make the switch, shop our Face & Body SPF 50, formulated with mineral filters from day one.

This article references a study published via ACS Publications and reporting on TGA guidance current as of September 2026. It is general information, not medical advice — speak to your GP or pharmacist about any specific health concerns.