Get the Antibacterials Out… Of Your Plastic!

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?

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. Antibacterials not only kill the germs that make us sick, but also the good bacteria that help to fight off the bad. 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. 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’.