Years ago, mineral sunscreens were very white and chalky – and therefore less appealing for people to want to use everyday. To create sunscreens that are both usable and effective, manufacturers often use nano size versions of these minerals – materials measured in nanometers (nm), or billionths of a metre – to increase clarity and SPF. 

The use of nano-zinc oxide is sometimes controversial in SPF beauty products, with some believing nano particles can penetrate the skin and get into the bloodstream. Our position on nano-zinc is based on advice from a global international authority on sun protection and the Environmental Working Group’s (EWG) recommendations and research.

  • Sunscreens made with the minerals zinc oxide and titanium dioxide score well in the EWG’s ratings, because they provide strong sun protection with few health concerns and don’t break down in the sun.
  • While a number of companies sell products advertised as containing non-nano titanium dioxide and zinc oxide, these claims are generally misleading. Although zinc oxide particle sizes do vary among manufacturers, nearly all would be considered nanomaterials under a broad definition of the term. Any particle smaller than 100nm is classified as nano. In simple terms, any mineral sunscreen that doesn’t leave a heavy white film would be nano.
  • Nanoparticles in sunscreen don’t penetrate the skin. Some studies indicate that nanoparticles in large doses can harm living cells and organs. But a large number of studies have produced no evidence that zinc oxide nanoparticles can cross the skin in significant amounts (SCCS 2012). A real-world study tested the penetration of zinc oxide particles of 19 and 110 nanometers on human volunteers who applied sunscreens twice daily for five days (Gulson 2010). Researchers found that less than 0.01 percent of either form of zinc entered the bloodstream. Furthermore, the study could not determine whether the zinc in the bloodstream was insoluble nanoparticles, so the European regulators concluded it was most likely zinc ions, which would not pose any health risk (SCCS 2012). A study by Italian researchers focused on the potential for nanoparticles to cross damaged skin and found no evidence this actually happens (Crosera 2015).

Some brands do advertise their products as having non-nano zinc oxide and titanium dioxide. Here they often get a bit innovative – when several nano-zinc particles stick together, the "cluster" is bigger than 100nm. Still, the single particle will be smaller and nano-sized. We could claim this for our brand and argue that we are non-nano, but we believe it is misleading to do so.