How ‘Bout Them Parabens?

Time to talk about preservatives.  This is a pretty touchy subject with a lot of big guns on both sides of the debate.  Let’s see where we go…

The first thing to mention is that preservatives can be toxic.  Of course they can.  Their sole job is to kill things so that our products stay fresh and usable.  Preservatives kill off nasty microbiological organisms like viruses, bacteria, yeast and mold.  That’s a good thing right?  Otherwise we would only have local cosmetics that have to be kept in the refrigerator and replaced every few days.  No more national brands and a big upswing in the sale of portable coolers.

I mean, how clean are your hands?  Pretty darn clean you think.  You think incorrectly.  One of my favorite show and tell demos when training new chemists is to ask them just like I asked you how clean their hands are.  Then I have them put their thumb on the agar in a micro plate.  (Agar is what we use as food to test for microbial growth.  Give ’em food, a moist warm place to thrive and see if it can survive.)

Two days later, I show them the plates.  And the amount of growth is always amazing.  All kinds of bumps and fuzz of many different colors.  Now we know with great certainty who washes their hands after using the restroom and who doesn’t.  It is truly an eye-opener.

Wash your hands!

Wash your hands!

So if a scientist’s hands which are washed religiously and covered with gloves aren’t clean, how do you think the average person’s hands compare.  Chemistry 101: A real chemist washes their hands before they use the restroom as well as after.

And you think nothing about sticking your finger into your jar of cream after a long day?  Ugh!

OK, so now we know that things are dirty and that preservatives are used to combat all the nasties that can grow on our skin.  So let’s cut to the chase and get to parabens.


Parabens: A group of preservatives (esters of p-hydroxybenzoic acid) used very commonly in cosmetics, food, pharmaceutical and industrial products.  You can find them on labels listed as: methylparaben, propylparaben, ethylparaben, butylparaben, isopropylparaben or isobutylparaben.  They were first introduced in the 1920’s, hit commercial cosmetic use in the 1930’s, were first listed as GRAS (generally recognized as safe) in 1995 by the US EPA at a combined percentage of 0.8% in cosmetic products.  The average cosmetic concentration of parabens usually runs between 0.20-0.40%.  And as with any material, it is possible to be allergic to parabens.

But in 2004, there was a study by Dr Philippa Darbre at the University of Reading that showed out of twenty breast tumors studied, all of them had parabens in them.  Wow. That set the press in motion and before long many thought that parabens cause breast cancer.  Why would they think that?  Well, it seems that parabens (butylparaben is the most potent of the family) have some oestrogenic activity.  Estrogen is an endocrine distrupor.  Disrupt the endocrine system enough, cancer can grow.  The test was published in the Journal of Applied Toxicology.

So on the one hand, there are a few studies that show a causal link between parabens and breast cancer.  However, those studies bring more questions than answers.  On the other hand the US, EU, Japan, the National Cancer Institute and several respected naturalists do not see any cause for alarm.  The oestrogenic activity of parabens is approximately 100,000 times weaker than a woman’s natural estrogen.

Give the public what it wants.  Several groups have reopened studies on parabens and more work is being. done.  We should probably ban everything that causes cancer, huh?

Did you know that all plants naturally produce p-hydroxybenzoic acid?  They produce parabens to protect themselves against attack by micro-organisms.  Gee, just like we use them in cosmetics and personal lubricants!  And guess what?  Almonds, apples, broccoli, cherry, mango and many, many more have potent oestrogenic activity.  We consume more parabens through organic foods than we get from cosmetics.

Fruit Basket!

How does it end?  Parabens have been used safely for over 50 years.  They are stable, recommended for use with sensitive skin and no link has been conclusively shown between parabens and any cancer or illness.  If the thought of using them makes you uncomfortable, read the labels and buy products with alternative preservative systems.  It does however remind me of an old saying,

“A rumour can run around the world before the truth gets its shoes on.”

1,4-Dioxane – Are we all going to die?

So there I was a few months back, blissfully washing my hair.  (Yes, I still have some.  There’s not much there, but it is all mine!)  When my attention was brought to an article proclaiming that many name brand organic shampoos contained 1,4-dioxane a listed carcinogenic material.

My first thought was, “Now I know why all my hair is falling out!”

My first thought was incorrect.

So, let’s talk about 1,4-dioxane and what it means to us.

What is 1,4-dioxane?  Looking to the US Department of Health and Human Services, we find that 1,4 dioxane is used as a solvent in processing other materials and is used as a reagent in laboratories.  One use common to our lives is when manufacturers treat vegetable oils with 1,4-dioxane to help them function as a surfactant.  So that’s where it might show up in organic or natural shampoo.

Where is it? You know, it can show up just about anywhere.  It has been found in tap water, in contaminated air, contaminated food, cosmetics and more!

Cosmetics?  Yep.  It can appear as a trace contaminant because of reasons we talked about earlier.

Wait!  You’re a chemist!  I sure am!  And I do believe in better living through modern science, but that doesn’t mean I support all things chemical.  There is an old saying that goes “The dose makes the poison.”  For example, belladonna – a little inflames, a lot kills.  1,4-dioxane – a lot can cause liver and kidney damage, a little, well we just don’t know what happens.

Can I avoid it?  Sure!  If you would like to avoid 1,4-dioxane, avoid all products that have some of the following words: PEG, Polyethylene, Polyethylene Glycol, Polyoxyethylene, -eth or -oxynol-.  Many chemical manufacturers have added a simple cost-effective process that removes any remaining contamination, but there is no way the consumer can know from whom the shampoo guys buy their chemicals.  Call the 800 number or send an email or letter to the maker of your products and ask.  I would answer it.  They should too.

Will it cause cancer?  Tough question.  It does pose a risk in animals but not aquatic ones apparently.   Fish and plants do not seem to accumulate it.  There are no studies or tests done in humans.  Just hasn’t happened.  The risk is rather unknown.

HUH?  What few studies have been done show that there is a generally accepted safe exposure limit of 10 ppm of 1,4-dioxane.  It is listed as reasonably anticipated to be a human carcinogen.  That means it hasn’t been proved conclusively, but the likelihood is high. 

Now what do we do?  Well, you can avoid cosmetics that have chemical names like those outlined above, if you live near a hazardous waste dump, don’t drink the water and don’t let your children play near the dump.  Especially after a good rain.  1,4-dioxane is stable in water.  Drink uncontaminated bottled water.

You can ask your doctor to test you for exposure, but he probably won’t have the equipment.  However he can collect the samples from you (urine or blood) and ship them to a lab.  But it has to be quick.  1,4-dioxane and its byproducts leave the human body fairly quickly.  So if you think you have been exposed to high amounts, test within a couple days.

Friend or Foe?  The jury is out on this one.  I will call it personal choice.  I know that my products use uncontaminated surfactants.  But if you aren’t sure, I would recommend that you avoid it.

Questions?  Send me a note!  I will answer, maybe privately but very likely in this column.  Let me know if you need your identity hidden for privacy.

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