Here is something I just found about "micro" vs "nano" at
http://bubbleandbee.blogspot.com/200...1_archive.html. It's on the Internet, so it must be true, right?? (LOL). Anyway, it gives thumbs up for Badger Balm and Mexitan and claims that these products' "micronized" TTO is not absorbed into the skin.
"In their natural, non-nano form, titanium dioxide and zinc oxide are my safer sunblock agents of choice. The most difficult thing is that companies don't usually disclose if they're using nanoparticles. So, it could be listed as zinc oxide and we don't know if it's "regular," "micronized," or "nano." Micronized is smaller than natural and larger than nano. Most companies claim that micronized particles are not absorbed into the skin.
The Safer Choice: Non-Nano Titanium Dioxide and Zinc Oxide. Zinc Oxide especially is a great sunblock agent. It gives you both UVA and UVB protection. This is the old-fashioned zinc oxide you see in old surfing movies---the white pasty stuff. Yes, it's not as convenient, and it's not as fashionable, but it's the safest and gives you the best protection. One thing to consider when using a zinc oxide sunblock is to apply it frequently. Zinc oxide is a powerful anti-inflammatory, so it's going to soothe your skin. So much, in fact, that you could be sunburned and not know it. After your day in the sun, you go in and rinse off the zinc oxide and you could be deeply burned. This is why I always recommend to apply it every hour to make sure you've got adequate protection, even if you feel like you're not getting burnt.
Update:
Badger Balm and Mexitan use micronized particles instead of nanoparticles. They claim that the particles are not absorbed into the skin. So far, these two products are the safest that I've seen."