Do you avoid chemical sunscreens? Many consumers understandably choose to use titanium dioxide and zinc oxide as their preference for sunscreen filters.
Titanium dioxide or zinc oxide have been used for many years in combination with chemical sunscreens to enhance protection levels in the longer UVA range (370 nm). Unlike chemical sunscreens, titanium dioxide and zinc oxide work by reflecting and diffusing UVR. Titanium dioxide and zinc oxide are hard to disperse and also leave the skin looking white on the skin, which is very undesirable. As a consequence of this the minerals were ground into a finer particle size and micronized.
Micronized Zinc Oxide and Titanium dioxide is the type used when the sunscreen does not leave the skin white and it is almost transparent. Micronized zinc and titanium undergo a chemical surface treatment to stop them clumping. What is not well known however is that the process of micronization leads to changes in the sun protective properties of titanium dioxide. The smallest particle shifts its protection from the longer UVA towards the UVB range.
Often when companies are citing Zinc Oxide gives full spectrum coverage they are referring to studies on the normal grade of titanium and zinc oxide, and this does not apply to micronized as the level of sun protection has been altered. This is primarily the reason chemical sunscreens exist. In Australia you need both. We have very high levels of UV exposure.
UVA is also being found to be more highly linked to melanoma. Protecting yourself from burning is not enough. You need full coverage protection from the sun.
