Much-maligned ingredients: Phthalates

So what are phthalates? They are esters of phthalic acid (an aromatic dicarboxylic acid) used as plasticizers, emulsifiers, and lubricants. They have low water solubility, high oil solubility, and low volatility. They're found in fragrances, nail polishes, and many other cosmetic ingredients. They are suspected of being endocrine disruptors, that is to say they "interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis (normal cell metabolism), reproduction, development, and/or behaviour." (From Wikipedia.)

There are dozens of different phthalates. Dibutyl phthalate (DBP) is one of the main offenders - it's used as a plasticizer for nail polishes. Diethyl phthalate (DEP) is the one found mostly in fragrances.

From the Suzuki Foundation report (page 5):
Other phthalates are widely used as fragrance ingredients in cosmetics – in particular diethyl phthalate (DEP). DEP is suspected of interfering with hormone function (endocrine disruption), causing reproductive and developmental problems among other health effects.

In their response to the Foundation report, Health Canada states:
Many scientific reviews in Canada, the U.S. and the E.U. have shown that the phthalates most commonly used in cosmetics (DBP–dibutyl phthalate and to a lesser extent, DEP–diethyl phthalate) are safe at the levels at which they are currently used in cosmetics.

There's an entire report (from 2002) from the Safe Cosmetics organization called Not Too Pretty: Phthalates, Beauty Products and the FDA if you're interested in reading more about this topic. And there's a paper from the European Commission on various endocrine disrupting chemicals.

So what's the deal with phthalates? Are they dangerous? Can they can mutate sperm or cause endometriosis in Japanese women?

From How strong is the evidence of a link between environmental chemicals and adverse effects on human reproductive health? from the British Medical Journal (2004):
Similarly, direct measurement of certain phthalate metabolites is significantly related to reduced semen quality in men, endometriosis in women, and shorter gestation periods in pregnant women. Although these new findings are suggestive, for none is the mechanism of the chemical's effect self evident. This leaves doubts as to whether the measured chemicals are the real culprits or are surrogates for other chemical exposures or lifestyle practices...Despite these examples, the evidence linking human disease and exposure to environmental chemicals remains sketchy.

Many fragrance manufacturers are removing phthalates from our fragrance oils and labelling them as such. If you're worried, speak to your supplier to find out if your fragrances are phthalate free.

Join me tomorrow for a little holiday merriment as I take a break from the maligned ingredients series and concentrate on Christmas!