'Part of the problem is that only within the last 10 years have scientists come to understand the biomechanics of UVA damage. "Up until 1995 the thinking was that UVA was not as important as we now know," Dr. Rigel said.
So far the Food and Drug Administration has approved only three ingredients protective against UVA: zinc oxide, titanium dioxide and avobenzone (trade name Parsol 1789).
But Mexoryl seems more effective than any of these at protecting against UVA light. In 2000, Canadian and French researchers slathered six brands of sunscreen and sunblock on the backs of volunteers and exposed their skin to a UV sunlamp for 15 minutes. The product containing Mexoryl (along with avobenzone, titanium dioxide and other ingredients) was more than twice as effective in protecting against UVA light as any of the others. The study was published in the Journal of the American Academy of Dermatology.
Mexoryl's secret is its chemical structure, Dr. Rigel said. "You can achieve much more efficient and powerful and effective protection with this one ingredient, or you can add it to another ingredient and get an incredibly high SPF protection level, all the way up to SPF 90," as well as UVA protection, he said.'
My friend in South Africa uses spf 100 sunscreen.
zinc oxide........that's the white butt medicine for babies' diaper rash. We use it for our horses who burn easily. 'Course, the horses sneeze and snort, they just DON'T like the smell.