Parabens can be found in shampoos, commercial moisturizers, shaving gels, cleansing gels, personal lubricants, topical pharmaceuticals and toothpaste. They are also used as food additives in some products. Chemically, parabens are esters of p-hydroxybenzoic acid. The most common parabens used in cosmetic products are methylparaben, propylparaben, and butylparaben. Typically, more than one paraben is used in a product, and they are often used in combination with other types of preservatives to provide preservation of product quality.
There are rising concerns of potential health hazard associated with long term exposure to Parabens. Parabens can mimic the hormone estrogen, which is known to play a role in the development of breast cancers. A study published in 2004 (Darbre, in the Journal of Applied Toxicology) detected parabens in breast tumors. The study also discussed this information in the context of the weak estrogen-like properties of parabens and the influence of estrogen on breast cancer.
In the July 2002 issue of the Archives of Toxicology, Dr. S. Oishi of the Department of Toxicology, Tokyo Metropolitan Research Laboratory of Public Health reported that exposure of newborn male mammals to butylparaben “adversely affects the secretion of testosterone and the function of the male reproductive system.”
Both Sodium Lauryl Sulfate (SLS) and its close relative Sodium Laureth Sulfate (SLES) are commonly used in many soaps, shampoos, detergents, toothpastes and other products that we expect to "foam up". Both chemicals are very effective foaming agents, chemically known as surfactants.
SLS and SLES are esters of Sulphuric acid - SLS is also known as "Sulfuric acid monododecyl ester sodium salt“. In fact, SLES is commonly contaminated with dioxane, a known carcinogen. Although SLES is somewhat less irritating than Sodium Lauryl Sulfate, it cannot be metabolised by the liver and its effects are therefore much longer-lasting.
The sodium lauryl sulfate found in our soaps is exactly the same as you would find in a car wash or even a garage, where it is used to degrease car engines.
In the same way as it dissolves the grease on car engines, sodium lauryl sulfate also dissolves the oils on your skin, which can cause a drying effect. It is also well documented that it denatures skin proteins, which causes not only irritation, but also allows environmental contaminants easier access to the lower, sensitive layers of the skin.
Perhaps most worryingly, SLS is also absorbed into the body from skin application. Once it has been absorbed, one of the main effects of sodium lauryl sulfate is to mimic the activity of the hormone Oestrogen. This may be responsible for a variety of health problems from PMS and Menopausal symptoms to dropping male fertility and increasing female cancers such as breast cancer, where oestrogen levels are known to be involved.