Originally Posted by Adagio Corse
Avoid the nano-version of certain lotions, because they appear to be toxic due to their ability to enter the skin and into the tissues.
The BEST solution has always been to wear a large sunhat or use an umbrella. Zipp needs to make an aero sunhat for us summer bikers. I find that the helmets with the visors shade my nose and face quite well during periods of intense sunlight (11am-2pm).
Nano particles are virtually impossible to unclump. Because they are so small, the inter-particle forces over comes the body forces and they always end up turning into big clumps of non-nano balls. It's the big problem with nano-particles, you can make em but they bunch right back up again...its all just marketing (especially in sun block)