Parabens are antimicrobials; preservatives used to give products an extended shelf life and to prevent them going bad.

Parabens are everywhere; they are not only used as a preservative in cosmetic products, but also in food. A 1995 study showed that they were present in 99% of leave on cosmetic products, and 77% of rinse off products (Rastogi et al., 1995 cited in Darbre et al 2004). Parabens are easily absorbed through the skin.

There are several different types of paraben preservative which are used depending upon the ingredients needing to be preserved. These include methylparaben, ethylparaben, propylparaben, butylparaben and isobutylparaben, benzylparaben. There may be multiple parabens used within a particular product.

The main area of concern surrounding parabens that most people are now aware of is regarding risk of breast cancer. This stems from a study by Dr Phillipa Darbre at Reading University in 2003, in which traces of parabens were found in the breast cancer tumours.

Studies have shown parabens to be endocrine disruptors, in other words that they are able to affect hormone levels. Because "oestrogen is known to influence the incidence of breast cancer" (Lipworth, 1995 cited in Darbre et al 2004) it was suggested that parabens might affect the occurrence and treatment of breast cancer.

Darbre's study did find parabens in the breast cancer tissue that was analysed but this does not mean that the parabens were what caused the cancer. However it does it mean parabens are able to get into body tissues and stay there without breaking down, which is a worrying thought since no one knows if and what harm they may cause.

Further research is needed to determine the full implications of parabens on human health and cancer risk, but there is no need to expose oneself to unnecessary risks.