Ethylparaben is a ethyl ester of hydroxybenzoic acid. Hydroxybenzoic acid compounds are more commonly known as parabens, which are used as preservatives in cosmetics, pharmaceuticals, and as a food additive to inhibit fungal growth. Parabens have also been found in breast cancer tumors. Though considered safe in the very low concentrations of 0.04% to 0.08% generally used in products, several studies suggest a link between parabens and breast cancer.
The Food and Drug administration (FDA) in the United States has found that parabens have the capability to mimic the female hormone estrogen in the human body. Evidence suggests, however, that this effect is negligible and does not increase natural estrogen levels. Despite such positive scientific findings as to the safety and tolerance of ethylparaben at the concentration levels currently used, it is one of many synthetic preservatives of which manufacturers are trying to reduce the use. Many cosmetics products are now being marketed as paraben-free in order to avoid any possible dangers the chemicals pose.
Several compounds related to ethylparaben are also used as fungicide-based preservatives. Methylparaben is a related chemical preservative that is often used to inhibit the growth of Drosophila larva, commonly known as fruit flies, in foods. Propylparaben is another paraben-related compound used as a fungicide, with the unique characteristic that is a naturally occurring chemical found in many plants and some species of insect. Butylparaben is often used in medicines as another derivative of the paraben family of compounds.
Controversy over the safety of products containing ethylparaben may continue for some time since studies of its adverse effects are small and limited in scope. A 2004 study published in the Journal of Applied Toxicology found that 60% of breast tumors were centered in a small area near the underarm, where deodorant is most often applied. Out of the 20 cases of malignant breast tumors studied, 18 had high concentrations of parabens in tumor cells.
Attempts to replace ethylparaben in the industries that rely upon it has resulted in the development of phenoxyethanol, which serves as both a preservative and ingredient in fragrances. Paradoxically, phenoxyethanol appears to have broader risks than ethylparaben and the other parabens it is designed to replace. Warnings have been issued about creams that contain phenoxyethanol for its potential toxicity to the immune system and non-reproductive organs. Restrictions on the use and labeling of products containing phenoxyethanol exist in Japan and the European Union. Studies in Canada for its tendency at bioaccumulation in the human body, however, have shown no risk.