The global sunscreen market is seeing a surge in mineral-based formulations as consumers move away from chemical sunscreens over concerns about toxicity, environmental impact, and efficacy. But experts warn that many common beliefs about the differences between the two types are riddled with misconceptions.
Professor Brian Diffey, emeritus professor of photobiology at the University of Newcastle, points out that the terminology itself is misleading. “Everything is a chemical,” he says. So-called chemical sunscreens are more accurately termed organic, as they contain carbon-hydrogen bonds, while mineral (or inorganic) filters such as titanium dioxide and zinc oxide lack those bonds.
One persistent myth is that mineral sunscreens work by reflecting UV rays, while chemical ones absorb them. However, a 2015 peer-reviewed study found that modern titanium dioxide and zinc oxide reflect or scatter only 4-5% of UV radiation, absorbing the remaining 95%. Professor Antony Young of King’s College London confirms that “people say mineral or inorganic sunscreens reflect ultraviolet radiation—and that’s not true.”
The history of sun protection dates back millennia, from ancient Mesopotamian umbrellas to ochre-based pastes used in Africa. Commercial sunscreens emerged in the 19th century after scientists discovered that ingredients like quinine sulphate could absorb UVR. Today’s organic filters, including avobenzone and oxybenzone, are often lab-synthesised, as are the titanium dioxide and zinc oxide used in mineral versions.
Despite marketing claims, neither type is completely natural, and both function primarily by absorbing UV radiation. Consumers should base their choice on skin sensitivity, ingredient preferences, and environmental considerations rather than on the misleading “physical” versus “chemical” labels.
