Zinc Oxide sunscreen forms a protective layer over the skin when applied, absorbing the suns UV rays and reflecing the suns visible light, providing full spectrum protection. When Zinc Oxide absorbs the suns rays they are converted into heat, which is comparatively harmless provided the wearer is responsible with their time in the sun. This makes Zinc Oxide the most effective sunscreen as it is effective unlike some other forms of sunblock, and also harmless towards people, as non-nano Zinc Oxide does not get absorbed into the bloodstream, making it completely safe.