Day Defence SPF25 contains Zinc Oxide micronized down to a very small level and is counted as a nanoparticle. We use it because even at this very small size is not water soluble and does not pass through the skin barrier. We were really careful before including a nano particle in a Skin Shop product. We reviewed all the evidence and especially The European Commission’s Scientific Committee on Consumer Safety published in April 2014 which states that zinc oxide nanoparticles “pose no or limited risk”.
We also love Zinc Oxide as an ingredient for its range of benefits other than as a sunscreen. We actually include non nano Zinc Oxide as a ingredient in other products for its effects other than being a sunscreen.