Possible pathways for chemicals to penetrate the skin

  The skin has many functions.  It serves as a barrier to prevent pathogens and bacteria from entering the body. Skin also contains a variety of nerve endings that react to heat, cold, touch, vibration, and injury.  Other functions are to control evaporation, to regulate fluid loss, and to keep the skin surface relatively dry. However, the most important and potentially dangerous function that affects the use of skin products is absorption.  Dermal absorption depends on numerous factors including the concentration of the substance on the skin, the duration of contact, and the location of the substance on the body.  Some areas of the body's skin absorb more rapidly than other areas.



This picture shows the routes of penetration a chemical might be absorbed into the skin through.
(1) across the intact epidermis layer
(2) through the hair follicles with the associated sebaceous glands
(3) via the sweat glands

       After the substance is absorbed,  it travels throughout the body, including into the internal organs.  When absorbed, the chemicals are stored in the fat layers of the skin and soak into the body and its organs.  Chemicals absorbed through the skin have been linked to genetic alterations, tumors, and birth defects.  These possible effects may not show themselves until years after the exposure or contact.