I remember reading that the soles of the feet absorb the most of what they touch. I always think of this when choosing shoes.
I’ve been searching for safe soles ever since. I’ve learned about all of the extremely harmful chemicals in leather and learned that the traditional and natural method of tanning leather is to use the animal’s brain (“brain-tanned” leather). Obviously, these shoes are impossible to find!
The footbeds I wear include natural and toxin-free rubber (flip-flops), cork, toxin-free wood, vegetable-tanned (chrome-free) leather, toxin-free jute, organic cotton and earth (barefoot).