Some people are trading chemical sunscreens in favour of mineral versions because of fears over toxicity, pollution and effectiveness. Is there actually any difference? Mineral sunscreen is having a moment. Amid concerns that so-called "chemical" sunscreens may be bad for our bodies, brains, and even coral reefs, mineral-based formulations have become the fastest-growing share of the global sunscreen market. But debates over "chemical" versus "mineral" sunscreens are riddled with misconceptions. Many commonly repeated claims – such as mineral sunscreens not containing chemicals; that chemical sunscreens have been proven harmful; or that chemical sunscreens absorb UV, while mineral ones only reflect it – are misleading, even false. The confusion begins with terminology. "Everything is a chemical," points out Brian Diffey, emeritus professor of photobiology in dermatological sciences at the UK's University of Newcastle and inventor of sunscreen's UVA star rating. What people call "chemical" filters are more accurately termed organic, since they contain carbon-hydrogen bonds, says Diffey. Inorganic filters (often called mineral), primarily titanium dioxide and zinc oxide, lack those bonds. All are chemicals.