The blog formerly known as   Fake Plastic Fish

March 23, 2010

Get the Antibacterials Out… Of Your Plastic!

polypropylene containers can contain antibacterial additives

Many of us have seen hand soaps and household cleaners that contain antibacterial chemicals like Triclosan. But did you know many plastic food containers do too?

What’s wrong with antibacterials?

  1. All this germ phobia is actually compromising the immune systems of growing children who need to be exposed to a certain amount of germs in order for their bodies to learn how to fight them off.
  2. Antibacterials not only kill the germs that make us sick, but also the good bacteria that help to fight off the bad.
  3. These additives don’t actually kill all the bacteria. Just the weaker ones. So in this way, we are actually developing strains of superbugs that are increasingly resistant to the chemicals we use to fight them off.
  4. Triclosan is actually a suspected hormone-disruptor.  Not a great chemical to have in our homes — for our health as well as that of the planet.

What about our plastic containers?

So many of us are opting for natural cleaners like vinegar and baking soda, but how many of us consider the plastic containers that our natural cleaners are bottled in, much less the plastic containers we might store our food in.

Polypropylene (#5 plastic, or PP) has long been considered a “safe” plastic for food-ware.  But over a year ago, some researchers in Alberta, Canada discovered quite by accident that their results were being affected by chemicals leaching from the PP test tubes they were using.  One of those chemicals was quaternary ammonium biocide — an anti-bacterial agent that manufacturers add to plastics.

This finding prompted a study of chemicals that can leach from plastics formerly considered to be inert.  In November 7, 2008, the researchers published their study, “Bioactive Contaminants Leach from Disposable Laboratory Plasticware” (PDF), in the journal, Science.

Disposable plasticware is used in life science laboratories worldwide. Although labeling of plastics as “sterile” appears to offer researchers some assurance that products are free of bioactive contaminants, the presence of processing additives is unavoidable. Herein, we report identification of two additives leaching from disposable plasticware and demonstrate potent effects on enzyme and receptor proteins.

A quick Google search on “antibacterial additives in plastic” found a number of companies marketing these additives for use in plastics.  Two of these companies are Life Materials Technologies, Ltd;  and the RTP Company, which manufactures several types of antibacterial additives, including Microban, a Triclosan-based product.

The market for antimicrobial additives is growing!

Helmut Kaiser Consultancy did a whole study of the market for antibacterial additives in plastics and found it increasing steadily.

Antimicrobial can be used to control the build up and growth of bacteria in surfaces, such as plactics and other materials. The market for antimicrobial additives has been developing steadily, with the largest market share for the food and beverages industry.

Staying safe from germs… naturally.

So, what can we do to make sure the products we use are safe?  Choose materials such as glass, stainless steel or even wood. Wood is naturally antimicrobial.  In a study performed by researches at U.C. Davis, plastic cutting boards were found to hold and breed bacteria much more than wood.

We soon found that disease bacteria such as these were not recoverable from wooden surfaces in a short time after they were applied, unless very large numbers were used. New plastic surfaces allowed the bacteria to persist, but were easily cleaned and disinfected. However, wooden boards that had been used and had many knife cuts acted almost the same as new wood, whereas plastic surfaces that were knife-scarred were impossible to clean and disinfect manually, especially when food residues such as chicken fat were present. Scanning electron micrographs revealed highly significant damage to plastic surfaces from knife cuts.

Although the bacteria that have disappeared from the wood surfaces are found alive inside the wood for some time after application, they evidently do not multiply, and they gradually die. They can be detected only by splitting or gouging the wood or by forcing water completely through from one surface to the other. If a sharp knife is used to cut into the work surfaces after used plastic or wood has been contaminated with bacteria and cleaned manually, more bacteria are recovered from a used plastic surface than from a used wood surface.

(PDFs of the actual studies are here, here, and here.)

The UC Davis researchers note in their report that while other studies have claimed to refute their findings, those studies were performed using only new cutting boards.  But in the Davis study, cutting boards with knife cuts (i.e. most cutting boards used regularly)  presented the greatest difference between wood and plastic.

Apparently, plastic is more likely to breed bacteria than other materials, which is why manufacturers add antimicrobials to it.

Plastics without antimicrobial additives?

So, how can you find plastics without these additives?  The short answer is that you simply can’t.  Manufacturers are not required to disclose the additives in their plastics.  We know that chemicals like BPA and phthalates can leach from plastics.  What about all the other additives that we don’t know about?

Just one more reason to skip plastics altogether.  Even the “safe” ones.


This post is included in the March 2012 Green Moms Carnival on toxic chemicals hosted at Groovy Green Livin’.

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3 years ago

I have toe fungus and wanted to soak my feet in vinegar, baking soda, Epson salt and hydrogen Peroxide. I’m concerned about the material in the container I use for the soak because I don’t want the acidity of the solution to cause the container to leach toxins. What would you recommend is the best and least toxic container to use?

Betsy (Eco-novice)
11 years ago

Wow, Beth, this is really fascinating. I have one plastic cutting board that we use for cutting raw meat that we always put through the dishwasher after using (all my other cutting boards are wood/ bamboo). I will have to reconsider my belief that plastic is “safer.”

13 years ago

As a mother of a Kindergartener I am so confused! I want to pack healthy lunches for my daughter, but what the heck do I pack it in? I used to use plastic containers that were “safe” but then worried about the chemicals! I want to be earth friendly so I don’t like the idea of using baggies…those are plastic too! I want my daughter to get a healthy start, but what can I do? Anyone have safe ways to pack lunches?

13 years ago

My flatmate and I have wooden boards, but a few friends of mine use plastic boards. I’m going to tell them about this, even if they don’t so much care about the environmental aspect of it, who wants the nasty bacteria in their cutting boards, right?! i’ll encourage them to switch

@Lenetta: You’re right, dishwashers are not good for wooden cutting boards. The best is to simply clean them with water and a bit of dishwasher detergent if needed, and oil them sometimes with vegetable oil to keep the wood ‘elastic’ (sorry, I’m not english don’t know the word I’m looking for here)

Lenetta @ Nettacow
13 years ago

I have preferred plastic cutting boards for their ability to be thrown in the dishwasher (I don’t like to put anything wooden in there as I think it’s hard on the wood). Looks like I really need to do some re-thinking. Thanks for sharing!

13 years ago

I knew that wood had anti-bacterial properties with respect to using it as a cutting board but I had no idea that anti-bacterials might be added to my plastic cutting board AND that cutting board with cuts (clearly mine) would not be cleaned with soap and water. ARGH!

I have a couple of glass boards but I have heard they are bad on knives which is why I was still using my plastic cutting board. I guess I had better go out and find a new wood cutting board!

13 years ago

Gov. Christine Gregoire signed the No BPA Bill in Washington state, oulaw BPA in baby bottles, sports bottles. Not a complete victory but hell baby steps.

Just a quick note to let you know how much I am loving the Soda Stream, Haven’t bought a can or bottle of soda since I got it! Great little machine!

13 years ago

NPR has an interesting interview about MRSA: The Drug-Resistant ‘Superbug’ That Won’t Die:

13 years ago

Any ideas on the best way to get rid of my scuzzy old plastic cutting board? Are platic cutting boards made from #5 plastic- can I drop it in the Gimme 5 bin at Whole Foods?

13 years ago

This is the push I needed to get the kids stainless lunch gear. I’m sure the lunch sacks I’ve been buying have Triclosan. Also, I’ve been putting goldfish crackers in the little plastic containers that are supposedly BPA free. It’s hard with kids, but I really want to rid their lunches and our picnics of toxins!!! :)

Sense of Home
13 years ago

Great article! All the more reason to switch my left-over and lunch food containers to glass or stainless steel.

13 years ago

Wooden cutting boards are great – even better if you can get locally made using wood salvaged from old fruit trees. Our two boards are olive wood.

Striving for more whole, raw foods means using a cutting board more often. I highly recommend olive wood because it is durable.

13 years ago

And again, thank you.

Lara S.
13 years ago

This is very interesting information!! I’d like to know how the antibacterials added to the plastic affect the ability of the plastic to biodegrade… it would make sense that antibacterials could kill the potential biodegraders of the plastic garbage.

It is also interesting to me because last year, other students and I did a lab experiment using a pesticide, and we were told to use glass jars because the pesticide could adsorb to the plastic. I knew that plastics leach chemicals but hadn’t heard of this papers which also seems to include lab equipment and not only food containers. Now I confirm it was a good choice to use the glass jars!

Thanks for this thought-provoking information…

13 years ago

Ack! Thanks for sharing this, Beth, I had no idea. I’m trying to avoid new plastic, but I still have some old stuff kicking around.

13 years ago

Cool!I always thought wood was better!I’m going to tell my boyfriend this right away :) !

13 years ago

I just watched “Bag It” the 10-minute documentary about plastic grocery bags. The filmmaker posted it to the internet for all to see for free. Very awesome!

13 years ago

Yet another reason to get rid of that ugly white cutting board. Also, I’d like to thank my mother for not being so crazy about cleaning and germs, and for letting us eat pizza that sat out on the counter all night. I’m sure my immune system is much stronger for it.

13 years ago

Aha! I’m glad that my wooden cutting board has proven to be eco friendly!
I’ve had so many people tell me that I should switch to plastic- and I hate those plastic cutting boards. Yay!