Natural Products Against the Skin - Does it really matter?

Does what we put against our skin really matter?  This is a difficult one to compare those who have been exposed versus those who have not been exposed to chemicals on the skin.  Nearly everyone will have some exposure - even if only by accident, so we cannot form two groups to compare.  Also, it is not ethical to intentionally exposure humans to known harmful substances in the name of research.  Given this, we must use logic to anticipate the result.  

We DO know the skin can effectively conduct certain chemicals into the body.  This is demonstrated by the pharmaceutical companies who have created topical products such as anesthetics.  This is also a route of administration for some medications with transdermal patches (birth control patches, motion sickness patches, stop-smoking patches).    While these are in larger controlled amounts, it does demonstrate it is possible for substances to enter our bodies this way.  Things entering the body through the skin bypass the immediate journey to the liver which things consumed orally take because of a special detour in our circulation known as the hepatic portal circulation.  This means they will spend more time in the body and be carried to various locations before the liver is able to process and detoxify them.  Maybe we should be thinking more about what comes into contact through our skin through sources like laundry detergents and chemicals used for dry cleaning or treating certain fabrics.    While me may not know the true result of this exposure for years, why take unnecessary chances?