Phthalates, cancer and fertility: should we be concerned about what's in our skincare?

Dr Hannah Sweilam and Dr Haran Sivapalan

Phthalates (pronounced THA-lates) are in our cosmetics and are linked to fertility issues, birth defects, cancer, and a raft of other health disorders. But how concerned should we be? 

It seems phthalates are almost everywhere. These chemicals are found in a huge array of products, from skin care products, cosmetics and fragrance, to plastic food packaging and PVC (vinyl) flooring and they’ve got people worried. The health scare around phthalates concerns their ability to disrupt hormones, and formally they are referred to as ‘endocrine-disrupting chemicals’.

Growth, puberty, reproduction, and the control of nutrients in the body are all regulated by hormones, which explains why the potential effects of phthalates are so far-reaching and varied with links to declining fertility rates and certain types of cancer, including breast cancer.

So where are they?

Phthalates act as a binding agent, making mixtures more sticky and plastics more flexible. For example, dibutyl phthalate (DBP) is used in nail polish to make the product less brittle, and dimethyl phthalate (DMP) is added to hair spray to prevent the hair from becoming stiff. The phthalate most commonly found in cosmetics is diethyl phthalate (DEP), which is used in perfumes to make the scent last longer.


Phthalates are absorbed through our skin. They are also ingested (swallowed) when they leach into food from plastic packaging and children’s toys placed in the mouth are thought to be another source. And, they’re are inhaled when breathing in indoor air and dust. These phthalates come from plastic building materials and furnishings.


What’s the harm?

Studies show they could have an effect on:

  • Fertility (male and female)

The most thoroughly researched health effect of phthalates is that concerning their impact on male fertility.  There is a strong association between high levels of phthalates and reduced sperm quality.  There is evidence that phthalates impair male fertility by reducing production of testosterone, a hormone that is essential for the creation of healthy sperm.  Another albeit small study showed phthalates are also thought to hinder development of the sexual organs in male foetuses, affecting boys’ future fertility: higher levels of phthalates in the mother’s blood have been associated with a shorter ‘anogenital’ distance (distance from anus to base of penis) in babies, a condition associated with a decreased sperm count.

The effect of phthalates on women’s fertility has not been as widely studied.  A study in mice suggests that they disrupt the function of follicles in the adult ovary. Follicles contain the egg, and disrupting these structures could reduce fertility by impairing the ability of the ovary to produce oestrogen.  Another study, of women undergoing IVF, found that women who had the most phthalates in their system were twice as likely to suffer implantation failure as those with the lowest levels.


  •  Cancer

More attention is turning to the potential role of phthalates in breast cancer. One study found that women with breast cancer had higher levels of DEP (used in fragrance) in their system.  Another study concludes that a phthalate called benzylbutylphthalate (BPP) can stimulate a laboratory sample of breast cells to multiply and exhibit cancer cell characteristics. While the results of this study cannot automatically be applied to breast cells in a living human, they add weight to concerns that phthalates might increase the risk of breast cancer.



Where does this leave us?

On balance, studies indicate that most of the phthalates in our bodies are not derived from those we put on our skin, but rather from those we inhale or ingest. In fact, it is thought that the amount of phthalates we absorb through our skin pales into insignificance compared with the amounts we breathe in or swallow.  It is also suggested that concentration of phthalates is key, and that the concentrations found in cosmetics are too low to pose a significant health risk.

What’s more, the phthalates with the greatest evidence of health risks, such as bis(2-ethylhexyl) phthalate (DEHP), are less commonly found in cosmetics, and more frequently in food packaging and furnishings.

However, there are significant data gaps and some data needs updating. More research is required to identify with certainty the various sources of phthalates and the relative contribution of each route of exposure, and to more accurately understand and quantify all the risks.


What is being done?

The use of some, but not all, phthalates is controlled in the EU.  The EU has banned the use of DEHP, DBP and BBP in cosmetics. DEP, the phthalate most commonly found in cosmetics (particularly in fragranced products), is still permitted.  Of note, some companies can sneak banned phthalates into cosmetics by branding them as ‘fragrances’ rather than as binding agents.


Phthalates in toys and food packaging are also restricted. From 2019, restrictions will apply to electrical and electronic equipment, though these will not extend to building materials and furnishings more generally.  Research is ongoing and the regulations will likely continue to evolve.

What you can do

If you are concerned about phthalates in your products, you can limit your exposure by avoiding those that list dimethylphthalate (DMP) or diethylphthalate (DEP) as an ingredient, and by steering clear of fragranced products.  If the packaging does not make it clear, you can contact the manufacturer to ask if their products are phthalate-free.


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