What are Parabens?
Parabens are alkyl esters of the chemical compound, para-hydroxybenzoic acid. The five most commonly used parabens in consumer products are methylparaben, ethylparaben, n-propylparaben, n-butylparaben and isobutylparaben. Isopropylparaben and benzylparaben are used less frequently.
Parabens are used in a wide range of products for their bactericidal and fungicidal properties. They can be found in personal care products such as cosmetics, shampoos and body lotions and also in foods and pharmaceuticals.
Why should we be concerned?
Parabens are widespread in our environment (1) and are now measureable in house dust and indoor air (2), and have also been measured in human urine (3).
All the commonly used parabens possess the ability to mimic the action of the female hormone oestrogen (4). They are therefore, endocrine disrupting chemicals.
All parabens have been shown to bind to human oestrogen receptors and increase expression of oestrogen-responsive genes in human cells. For human cells which rely on oestrogen for their growth, parabens will also increase the growth of the cells (4).
How are parabens linked to breast cancer?
Parabens can mimic oestrogen action and have been measured in human breast tissue (5,6) at concentrations which are functionally capable of mimicking oestrogen action in a way which could lead to increased growth of oestrogen-responsive human breast cancer cells (7).
Breast Cancer UK position
- Breast Cancer UK supports the phase out of all parabens from all cosmetics and products designed to be applied to the skin.
- Breast Cancer UK supports an extension of EU Article 60 (3) of the REACH Regulation, to ensure EDCs (including parabens) are, by default, classed as Substances of Very High Concern (SVHC), for which no safe thresholds can be determined.
- Breast Cancer UK supports the inclusion of such chemicals to the REACH list of most harmful chemicals (Article 57 on SVHC), and support bans of these chemicals where safer alternatives and no predominant socio-economic need exists (Article 60.3).
- Bledzka D, Gromadzinska J, Wasowicz W. (2014). Parabens. From environmental studies to human health. Environ. Int. 67: 27-42
- Weschler CJ, Nazaroff WW. (2014). Dermal uptake of organic vapors commonly found in indoor air. Environ. Sci. Technol. 48: 1230-1237.
- Darbre PD, Harvey PW. (2014). Parabens can enable hallmarks and characteristics of cancer in human breast epithelial cells: a review of the literature with reference to new exposure data and regulatory status. J. Appl. Toxicol. (in press).
- Darbre PD, Harvey PW. (2008). Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks. J. Appl. Toxicol. 28: 561-578.
- Darbre PD, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope GS. (2004). Concentrations of parabens in human breast tumours. J. Appl. Toxicol. 24: 5-13.
- Barr L, Metaxas G, Harbach CAJ, Savoy LA, Darbre PD. (2012). Measurement of paraben concentrations in human breast tissue at serial locations across the breast from axilla to sternum. J. Appl. Toxicol. 32:219-232.
- Charles AK, Darbre PD. (2013). Combinations of parabens at concentrations measured in human breast tissue can increase proliferation of MCF-7 human breast cancer cells. J. Appl. Toxicol. 33: 390-398.
For more information and a full list of reference download our Background briefing on Parabens.
We would like to thank Dr Philippa Darbre, Associate Professor at the School of Biological Sciences, University of Reading, for her input and assistance in putting together this information.