Dgrad FAQ

What is oxo-degradable polyethylene?Oxo-degradable polyethylene contains an additive designed to accelerate break down of the polyethylene polymer molecules so they can eventually be digested by fungi and bacteria. The additives Manchester Packaging Company uses to achieve this have been tested by their manufacturers to show the degradation is real and that degradation products are not harmful to the environment. These additives cause the long polyethylene polymer molecule to be reduced through the action of temperature and sunlight.
What can you say about oxo-degradable polyethylene and what can you tell customers? You can tell customers the polyethylene bags you supply contain an additive that accelerates the break down of the polymer molecules into smaller molecules that eventually can be digested by microbes and fungi to produce water, carbon dioxide, and organic humus. Contrary to misinformation promulgated by various sources, the resulting break down products are not just "plastic dust." Tests by the additive makers show the break down products are not harmful to the environment.
How do the additives work? The additives work by increasing the rate of polymer oxidation. That's why they are called oxo-degradable additives. Like iron rusts when exposed to oxygen, polyethylene "rusts" with the help of the oxo-additives. Exposure to heat and/or sunlight speed up the oxo-degradation process.
How long does it take to decompose the film or bags with oxo-additives?This is where a lot of controversy arises. Most people think that because the film or bags contain a degradable additive they will start falling apart as they pass the lip of the trash can. Paper doesn't and neither will this material. Polyethylene without the degradable additives will take many years to break down in the environment - depending on the conditions of exposure to the elements. Polyethylene with degradable additive will take much less time (years less) in comparison under the same conditions – again depending on the conditions of exposure to the elements. Degradable polyethylene buried in a landfill will not decompose any faster than paper or other organic materials. Landfills are not designed to encourage degradation on purpose to protect the ground water from harmful leachates. So the short answer is - it depends.
Does oxo-degradable polyethylene meet the ASTM D6400 composting standard?Additionally, polyethylene with oxo-degradable additives will not meet the ASTM D6400 standard for composting. Very few managed compost operations exist in the United States.
Will the degradable bags have a storage shelf life? Absolutely. Because of manufacturing process to make polyethylene film and bags includes temperatures of 400 to 800 degrees Fahrenheit, and because degradation rates are affected by temperature, the act of producing the film and bags starts the degradation clock ticking. Bags have side seals in them where most of the process heat was concentrated during manufacturing. Side seals will fail first due to degradation. However the time it takes for degradation to result in seal failure or general material failure will depend on the level of degradable additive used and storage conditions. We usually try to formulate for a 6 month to one year shelf life and recommend storage temperature be kept under 100 degrees Fahrenheit. If sunlight exposure is expected for any length of time during use this should be communicated to us so we can work with our degradable additive suppliers to adjust formulation. Just keep in mind that storage, use, and disposal conditions all affect the speed of break down. A bag used in Phoenix will probably start to deteriorate faster than one used in Minneapolis.
What about product labeling? Be aware the Federal Trade Commission issued "Guides for the Use of Environmental Marketing Claims" in 1991. Don't make any claims you or we can not substantiate. Additionally, no standards for labeling degradable plastic currently exist to our knowledge. We recommend warning labels on cases that read "The bags in this case incorporate degradation additives to promote decomposition. They should not be stored at temperatures exceeding 100° F and should be used within one year of purchase," or something similar. We use a registered logo D-grad^®for many film and bag products we sell. You might want to develop your own logo.

MPC 2008