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SUMMARY POINTS
What’s Important?
Parabens are more likely to cause contact dermatitis on skin with a compromised barrier such as tape-stripped skin.
Preservatives in paraben-free products currently on the market are more likely to cause an allergic rection than parabens.
Only intact skin should come in touch with products containing parabens to prevent irritant reactions.
What’s New?
Experts have concluded that current scientific knowledge is insufficient to demonstrate a clear cancer risk due to the topical application of cosmetics that contain parabens on normal intact skin.
What’s Coming?
New preservatives will be developed that have no estrogenic activity and decreased allergic potential.
Organic skincare product choices without preservatives are becoming more efficacious.
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Preservatives are integral ingredients in various food, pharmaceutical, cosmetic, and skincare formulations. As water is included in most such products, preservatives are added to prevent the growth of microorganisms and the resultant rapid deterioration or decomposition of the formulation. Indeed, without preservatives, which are biocidal chemicals, these items important to daily life would exhibit little to no shelf life and become quickly invaded and permeated by numerous bacteria, fungi, and molds. As such, preservatives are intended to maintain the integrity of the product and protect the user from infection.1 While antimicrobial preservatives are essential components in the majority of cosmetics and skincare products, these ingredients have been cited frequently as causes of allergic contact dermatitis.1–3 Such occurrences are most often associated with topical application on damaged or broken skin. Of greater concern in recent years has been the reports linking the use of some skincare products with cancer incidence. This chapter will focus on the most frequently used class of preservatives, recent data regarding the estrogenic potential of these compounds, and the controversy regarding possible associations between the chronic use of chemical preservatives that make contact with the skin and cancer.
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Parabens, alkyl esters of p-hydroxybenzoic acid (PHBA), were commonly found in skin, hair, and body care products until the last 15 years when consumers became afraid of them. Parabens are found naturally in raspberries, blackberries, carrots, and cucumbers and are common ingredients in food and pharmaceuticals. Parabens were the most widely used preservatives in cosmetics and included in the vast majority of skincare formulations.4,5 In fact, in the early to mid-1980s, it was estimated that at least 90% of personal care products, including deodorants, toothpastes, shampoos, body creams, shower gels, moisturizers, etc., contained one or more parabens as a preservative.6 For decades, parabens had a strong record of efficacy, safety, and stability and were well tolerated except for occasional allergic reactions.7 Now paraben-free products prevail.
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Allergic Reactions to Parabens
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For years parabens had been thought to cause allergic reactions in susceptible individuals. The penetration ability of parabens is influenced by the inclusion in cosmetic preparations of penetration enhancers, which facilitate the ...