PDF details:
Skin physiology educational materials
The Skin as a Barrier. In: Loden, M and Maibach, HI, editors. Dry Skin and Moisturizers: Chemistry and Function. Boca Raton: CRC Press, 2000. p.27-37.
http://www.lni.wa.gov/Safety/Research/Dermatitis/files/skin_phys.pdf
