-by Ed Weisberg
We at GXT Green are pleased to see the increased attention being paid to plastic bag pollution. Over 6 billion plastic bags are littered each year, enough to circle the globe 63 times. As awareness rises, there is an increased number of towns, states, and municipalities who are trying to solve this problem for their citizens. Fortunately there is also a growing interest in alternatives to plastic bags, and a resulting proliferation of products targeting a solution to plastic bag pollution and offering alternatives to consumers and retailers.
Clearly, the world needs an alternative to regular plastic bags. Plastic bags take 400+ years to degrade, they emit large amount of Greenhouse Gases in production, they are manufactured from precious oil or natural gas, they don’t burn well, and they release large amount of greenhouse gases when incinerated. It’s time to move to alternatives to carrying our groceries home, and we can do better.
One of the most important initiatives that has been implemented to solve the problem is the development of a recycling stream for plastic bags. Bag manufacturers, as well as companies such as Trex that manufacture products made from recycled plastic bags, have setup infrastructures to collect and recycle used plastic bags. This continues to be a meaningful solution to eliminating plastic bag pollution and its resulting environmental impact. However, the recycling infrastructure is limited. In addtion, many consumers find it inconvenient to make the extra effort necessary to recycle bags and to ensure bags are not accidently released into the environment. Thus, over the past few years, there have been several attempts to develop an environmentally acceptable solution to plastic bag pollution. Let’s try to sort these out.
The Standards: Products are often tested against one or more acceptable international standards to certify compliance of its attributes. ASTM International, (formerly known as the American Society for Testing and Materials), is a globally recognized leader in the development and delivery of international voluntary consensus standards. They are the de-facto provider of over 12,000 standards that are used to certify product compliance and they provide a fair and meaningful way to categorize the various available solutions in the market. Below are the various approaches that have been taken under the auspices of ASTM certification to develop alternatives to regular plastic bags.
1: Compostable bags, certified under ASTM D-6400 standards. ASTM D6400 – 12 is the “Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities” Historically, ASTM 6400 standard was the first exception allowed in plastic bag bans. While it is a noble gesture, in fact, we believe that ASTM 6400 certified plastics are not at all a good solution to plastic bag pollution. By definition, these bags only degrade in “municipal or industrial composting facilities“ in a controlled environment. Unfortunately, only one such facility exists in the USA,( near San Francisco). So while the concept of allowing compostable bio-degradable bags as an exception to bans makes sense, reality is that, other than in towns near San Francisco that utilize this plant, this exception doesn’t actually offer a solution. Additionally, the most important impact of plastic bag pollution is from littering, and ASTM 6400 certified bags will not compost when they are littered! These bags will not degrade in your backyard compost pile and these bags cannot be recycled with other plastics, as they will continue to degrade and carry their degradation characteristic to the new products made from recycled bags. Also, these bags tend to be 3-4 times more expensive than plastic, which provides a financial dis-incentive to their adoption. So why has the ASTM 6400 exception been carried to so many other bans ordinances? My guess is that it is due to the desire to provide an alternative, and the lack of knowledge of other acceptable technologies.
2: Marine degradable bags certified under ASTM 7081 standards. ASTM D7081- 05 is the ” Standard Specification for Non Floating Biodegradable Plastics in the Marine Environment “. This certification is for plastics that can bio-degrade under the marine environmental conditions of aerobic marine waters or anaerobic marine sediments, or both. In some cases, such as in Brookline MA and in the MA State Senate proposed bill, this exception has also been allowed. Also an interesting idea – Unfortunately, as of today, we have not seen any bags that meet this certification.
3: Oxo-biodegradable bags certified under ASTM 6954 standards. ASTM D6954- 04 is the “Standard Guide for Exposing and Testing Plastics that Degrade in the Environment by a Combination of Oxidation and Biodegradation” . Oxo- biodegradable bags degrade from exposure to oxygen. By adjusting the amount of additive used, the time to degrade can be adjusted. This is an interesting concept. However, it can be problematic for a retailer who’s bags will begin to degrade while they sit in inventory. Also, this characteristic makes the bags incompatible for recycling with other bags, and difficult to continue to use around the house. Additionally, they use about the same amount of HDPE and plastic resin as a plastic bag, as the additive is generally mixed with the resin at about the 1% level. Therefore, they do not reduce our dependency on oil and gas for plastic bag manufacturing. Finally, metal salts used as the catalyst for OXO degradation carry risks of environmental pollution with heavy metals. A study by the Biodegradable Products Institute found significant amounts of lead and cobalt in commercially available Oxo-biodegradable bags samples that exceed safety standards.
4: Photodegradable bags certified under ASTM 5272 standards. ASTM D5272 – 08 is the “Standard Practice for Outdoor Exposure Testing of Photodegradable Plastics” . Photodegradable bags, such as the ECOgrade™ bag, degrade when exposed to ultraviolet rays from the sun. Photodegradable bags have been under extensive development for several years, since they are such an ideal solution. However, many types of photodegradable bags that were originally developed used heavy metal salts, such as cobalt, to initiate the degradation process. Unfortunately, that formulation has several side effects: The residue may not be environmentally safe, they could not be recycled with other plastics since the oxidizing agent continue to react with HDPE, and they are expensive. ECOgrade bags, which are a new invention, have overcome these issues, since they use Calcium Carbonate as the oxidizing agent, and do not contain harmful heavy metals. Calcium carbonate is a safe material, used as filler in pills, toothpaste, and is already used in as filler and stabilizer in many plastic bags. Thus, it is safe for the environment, can be recycled with other bags, and also is cost competitive with plastic bags. ECOgrade bags also use 50% less HDPE, reducing the dependence on oil and gas.
Thus, when considering solutions for bag pollution, it is important for retailers, as well as legislators, to be sure that they educate themselves on the alternatives. Increasingly, towns and cities that have instituted bans without solutions are seeing tremendous pushback from consumers and retailers who need a better solution. In some places, such as Toronto, the legislators have been forced to rescind their bans. In our opinion, ECOgrade bags, which are the latest in a series of steps to develop an alternative, are the only safe and viable alternative, as they are certified under ASTM 5272 standards, they can be recycled, use less energy, produce less greenhouse gases, and if they are littered, they degrade to a non-toxic residue. We believe that this is an ideal solution for the environment, retailers, and consumers.
If you want to learn more about the details of the ASTM specs, templates of how legislation has been written, or more about why ECOgrade bags were selected as MassTLC Consumer Product of the Year, please join our mailing list or contact GXT Green. If you are a retailer and you’d like to sample ECOgrade photodegradable bags in your store, you can request them here.
-Edward Weisberg is Senior Vice President of Marketing and Business Development, GXT Green