PHENOXYETHANOL: THE NEXT PARABEN?
First, they came for the Parabens. Then they came for the isothiazolinones. Now the bell rings for Phenoxyethanol. Are the naysayers right in avoiding this chemical preservative or are the ill-informed spreading rumours which aren’t true?
What is Phenoxyethanol?
Phenoxyethanol is a widely used synthetic preservative used in cosmetics to prevent the growth of microbes. First used in the 1950’s, due to the negative consumer backlash of Parabens, it is now one of the most common preservatives used in the marketplace. As the trusted adage says, “where there is water, there is life” and as most personal care products are made with water, microorganisms would jump at the chance to create a little thriving community of their own. If you don’t like slathering yourself with potential pathogens, this isn’t great.
So, preservatives are essential for skin health. This ingredient starts out as phenol, a toxic white crystalline powder that’s created from benzene (a known carcinogen) and then is treated with ethylene oxide (another known carcinogen) and an alkali (which isn’t a carcinogen, yay!).
Does Phenoxyethanol cause cancer?
Surprisingly, this isn’t a clear-cut answer. While phenoxyethanol is made from a slew of toxic, carcinogenic materials involving numerous, complex chemical reactions, the end result isn’t as toxic or carcinogenic as it’s precursor chemicals. However, it’s not always possible to form perfect reactions, there is always some contamination left over.
While the risk is pretty low, as the exposure to the cancer-causing contaminants is quite low in reputable brands, using a product with a small amount of Phenoxyethanol a few times isn’t going to start cleaving DNA at a rate which is likely to be a concern. However, Phenoxyethanol, along with other carcinogenic contaminants like formaldehyde, nitrosamines etc, is found in a wide variety of products with repeated multiple daily exposure and sadly many cosmetic ingredients made with Ethylene Oxide are tainted with Ethylene Oxide or its subsequent by-product, 1,4-Dioxane.
From the deodorants, moisturisers, soaps, aftershaves, toothpastes, shower gels etc, we could easily expose ourselves to worrying levels of carcinogens when we consider all the plastics like PVC, BPA & phthalates to pesticide residue in our food we are exposed to daily. Exposing yourself to a trace amount of one of these carcinogens in an isolated incident, it should do no harm. But over time, these trace amounts start to add up. If you can limit the toxic load, some of which are easily preventable, why wouldn’t you?
So, does Phenoxyethanol cause cancer? It could do but it probably won’t, no matter what some people might claim. Cancer is a horrible disease, so it’s all to often easy to grab our attention but it isn’t the small cancer risk which stopped us developing our formulations with Phenoxyethanol. It was two far more significant factors, the irritation and xenoestrogenic activity of it.
The xeno… what!? To simplify it, xenoestrogens are a type of compounds which imitates estrogen, the female sex hormone, in the human body. While men naturally have a small amount estrogen – I won’t bore you with the details but it’s part of how testosterone, the male sex hormone & other hormones are produced, this needs to be kept in check, not only in men but also women.
All three forms of estrogen (estrone, estradiol, and estriol) are made up of complex benzene rings. Estrogen receptors in the body are designed to react to these particular benzene rings. But when a synthetic chemical containing benzene rings, such as Phenoxyethanol or Parabens enters the body, it binds to estrogen receptors and stimulates cells incorrectly or disrupts the biometabolic pathways. Each variation is going to interfere in different ways, some more strongly than others. Studies have found that Pheoxyethanol interferes with estrogen receptors.
We know that exposure to xenoestrogens like parabens can increase the potential for hormone-related issues like PCOS and endometriosis in women, but how do phenoxyethanol impact men? Numerous studies have found xenoestrogens affect male reproductive health, lower sperm counts, prostate & testicular cancers and bone growth, blood clotting, immune systems & neurological systems in both men & women.
The irritation factor of Phenoxyethanol
So, it’s not really pretty then and considering consumers moved away from Parabens to escape the xenoestogenic activity of it to something else which has the same issue, albeit a bit less, it’s a bit of an oxymoron.
However Parabens are amongst the least irritating and allergenic preservatives on the market, with an allergy incidence of 0.5-1.7% in patch-tested individuals. For comparison other common, synthetic preservatives, the incidences reported in this review are:
- Formaldehyde: 9% (US), 2-2.5% (Eur)
- Quaternium-15: 9% (US), 1% (Eur)
- Diazolidinyl urea: 2.7-3.7% (US), 0.5-1.5% (Eur)
- Imidazolidinyl urea: 2% (US), 1% (Eur)
- Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) 2.3-2.9% (US), 2-2.5% (Eur)
- Phenoxyethanol 3.4 %
Phenoxyethanol on the other hand is almost 7x more irritating and allergenic at 3.4% which really puts it into perspective. Preservatives are not intelligent. Preservatives cannot differentiate between a mammalian cell such as ours and unwanted microbial cells. It’s this issue which can cause irritation.
The Bottom Line
With all the evidence on phenoxyethanol linking it to a high level of irritation a decline in reproductive health, we chose to not formulate with it and replace with a safer alternative, a preservative that we fully understand the method of action. Sodium Anisate and Sodium Levulinate cause the microbes to die by steadily supplying the microbe with electrolytes, reducing the pH inside the cell. The microbe tries to counter this by expelling protons, this process consumes energy.
Eventually the microbe is no longer able to expend energy or supply protons to counter the electrolytes, which kills the microbe. It’s this unique property which is magnitudes safer for use on the skin than other commonly used preservatives, with the preservative itself being fully bio-degradable, meeting OECD criteria, minimising risk to the environment and to you.
However, the preservatives we use are some of the most expensive on the market and the current parabens backlash doesn’t seem to be dying down either, causing many brands to switch their preservative choices, usually to Phenoxyethanol.
The bottom line is, there is still a lot we don’t know about phenoxyethanol and skin health but there is enough evidence to suggest you might be better off ditching phenoxyethanol in skincare but only if the alternative is something actually better. Should you though? That is a question we’ll leave up to you.
The science in skincare is our ongoing series helping consumers better understand the science in skincare. We translate the science into a format that is much easier to read, bust the myths and give you a clear, transparent and honest assessment so you can make an informed choice of what goes onto your skin.
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 Reproductive toxicology. Ethylene glycol monophenyl ether. [NCBI]  Male reproductive health and environmental xenoestrogens. [NCBI]  The most frequent allergens in allergic contact dermatitis. [NCBI]  Contamination versus preservation of cosmetics: a review on legislation, usage, infections, and contact allergy. [Wiley Online Library]