What are parabens? Parabens are a class of chemicals widely used as preservatives by cosmetic and pharmaceutical industries. Parabens are effective preservatives in many types of formulas. These compounds, and their salts, are used primarily for their bactericidal and fungicidal properties. They can be found in shampoos, commercial moisturizers, shaving gels, personal lubricants, topical/parenteral pharmaceuticals, spray tanning solution, makeup, and toothpaste. They are also used as food additives.
Their efficacy as preservatives, in combination with their low cost, the long history of their use, and the inefficacy of some natural alternatives like grapefruit seed extract (GSE), probably explains why parabens are so commonplace. They are becoming increasingly controversial, however, because they have been found in breast cancer tumors (an average of 20 nanograms/g of tissue). Parabens have also displayed the ability to slightly mimic estrogen (a hormone known to play a role in the development of breast cancer). No effective direct links between parabens and cancer have been established, however. Another concern is that the estrogen-mimic aspect of parabens may be a factor in the increasing prevalence of early puberty in girls.
Are parabens dangerous? A 2008 opinion on parabens from the European Commission's Scientific Committee on Consumer Products states that "methyl paraben and ethyl paraben are not subjects of concern," but that "the safety assessment of propyl and butyl paraben cannot be finalized yet." Rebecca Sutton, a scientist at the Environmental Working Group, a nonprofit advocacy organization, says her group is most concerned about propyl and butyl paraben too. But even though she says that parabens may disrupt hormones or mimic estrogen (which is thought to promote breast cancer in some women), "You certainly don't want parabens to be pulled out and a more dangerous preservative to be put in," such as one that releases formaldehyde. "Sometimes cosmetic companies might jump on the paraben-free bandwagon without really doing a proper assessment of … the safer preservatives that they ought to be adding."
In fact, she says, "It's difficult to declare a preservative 'safe.' … We have limited data to evaluate. We've been unable to create a list of safer preservatives at this time based on existing publicly available scientific literature."