[stormchaser]

chemicalmatt said:

Simply put: uncoated zinc oxide SPF products will report lower SPF upon aging than coated ZnO used. TiO2 behaves similarly but not as much delta-SPF.  Neither will react with/affect other ingredients as their chemical catalytic activity is smaller than, say, platinum. This is the conundrum we face: the organics are more stable (when formulated correctly), easier to work with, more ubiquitous, have better sensorial properties and more supply sources; yet FDA and the coral reef watchers make using them a difficult decision.

Thanks for the explanation, with coated zinc oxide, what kind of coating are they using? Are these coatings good for the environment?