Tue, 29 Jan 2008 06:57:56 -0500 support@imminst.org (ImmInst Forums) IP.Blog 60
It is not enough to protect sun-exposed skin with a sunscreen and believing that you are doing the right thing though:( Not all sunscreens protect fully from harmful UVA-rays (320-400nm)!

The best are the ones that have min SPF30 and contain either the photo stable Mexoryl XS+XL (patented filters by L`Oreal, protection up to 387nm, partially up to 400nm) or Tinosorb M+S (protection up to 378nm, partially 395nm). None of these combinations are available in the US though :(


We have of course the good old particle filters like TiO2 and ZnO which can give just the right UVA protection if they are formulated correctly. It is a must that TiO2 (if micronized -protection up to 360nm-, particle size >100) is combined with ZnO. Min, content of active ingredients should be 20%! Under this the UVA protection wont be adequate. If ZnO used alone (not nano form which is prohibited in EU, allowed in the US and AU, particle size >35, protection 360nm)than the concentration should be between 20-25% (protection up to 520 nm, hence the white residue . The general rule is that particle filters should leave a white-cast on the skin to be fully able to protect against the Sun`s harmful UVA rays (protection over 400nm!)

]]> Mon, 28 Jan 2008 10:43:34 -0500