How porous is human skin compared to various rocks and man-made materials and fabrics?

Human skin is a living organ, not upholstery. It is a complicated system designed mainly to keep things out (like bacteria, water, dirt). It is also necessary for temperture regulation, sensation, excretion of salt and water, and vitamin D synthesis.





Here's a diagram of skin. See how it's just full of stuff:


http://www.essentialdayspa.com/images/em...

How porous is human skin compared to various rocks and man-made materials and fabrics?
Human skin is porous but from inside out. If it where the other way (outside-in), we would drown when taking a bath or swimming. The porous condition allows our body to regulate internal heat, expressed in swet glands. Now, some skin products do actually penetrate the skin onto the blood stream, but this is after prolonged processess.