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.
AVOID THIS SHIT IF POSSIBLE! :)