Products
Parabens are found in numerous pharmaceuticals, cosmetics, and foods, among other products, as excipients or food additives.
Structure and properties
Parabens are ester derivatives of 4-hydroxybenzoic acid (= para-hydroxybenzoic acid). They exist as white, odorless and tasteless powders and are sparingly soluble in water. Water solubility decreases with the length of the side chain. Common parabens are alkyl derivatives such as:
- Methyl 4-hydroxybenzoate (methylparaben).
- Ethyl 4-hydroxybenzoate (ethylparaben)
- Propyl 4-hydroxybenzoate (propylparaben)
Parabens are produced synthetically, but also occur in nature. Due to the poor solubility in water, salts are also used.
Effects
Parabens have preservative properties with a broad antimicrobial spectrum against bacteria and fungi. They have been used since the 1930s as preservatives to inhibit germ growth and extend product life. Mixtures of different parabens are also frequently used.
Areas of application
As a preservative for pharmaceuticals, foods and cosmetics.
Adverse effects
Parabens are approved by regulatory agencies and are generally considered safe and non-hazardous (GRAS). However, they are controversial substances that are evaluated differently in the scientific literature and have a bad reputation among consumers. Parabens are acutely atoxic but can potentially cause longer-term side effects. The two main critical issues are:
- Parabens are weak allergens and may cause allergic reactions such as allergic contact dermatitis in a small number of individuals. Pre-damaged skin is considered a risk factor.
- The agents have weak estrogenic effects and thus can potentially be effective as endocrine disruptors.
Because of these concerns, paraben-free products have been developed for some time and marketed accordingly (“without parabens”). Traditionally paraben-free are, for example, genuine natural cosmetics and organic products.