The skin is the outermost layer of the body. It is just natural that it has its own primary defense system to counteract imbalance in its composition and also bacterial and chemical invasion. This is the most important role of the skin. Free radicals, on the other hand, are products of a lot of chemical [...]

Because of the skin’s status of being the body’s primary defense against bacterial or chemical invasion, it has one of the most complex systems of first and secondary reactions to foreign intrusion.

 
 
Reactive oxygen species are abundant from the sun’s rays. These species pass through the skin and leave trails of free radicals along the way. [...]