Bio-degradable/Oxy-degradable Plastics – Great Idea, But the Implementation Still Needs Work

What happens when an idea is actually revolutionary, but it is fighting the wrong battle and gets rushed into implementation without understanding the consequences?

What are Bio-degradeable/Oxy-degradeable Plastics?

Bio-degradeables are polymers that can degrade under a variety of conditions depending upon the additive or chemical composition of the the polymer.  There are two types of degradeable materials that are being marketed today: oxy or oxo-degradeables and anaerobic degradeables.   Oxy-degradeables have metal salt additives that allow them to decompose over time when left outdoors or composted, but will not decompose in a landfill.  Anerobic degradeables have a chemical additive in the plastic that allows it to degrade in a microbe rich environment, like a landfill, but no one is quite sure of the environmental impact of the residual chemicals that were added to the plastic.  Similarly, both resin types, when tested in their appropriate environments to degrade, take too long to degrade to be truly useful in commercial composting or landfilling applications.

Need to be labeled clearly

If the packaging industry still insists on providing products made with these types of resins, then the labeling has to be clear, such that these resins don’t get mixed in with 100% or previously recycled resins. Contrary to some claims by bio/oxy-degradeable resin suppliers, these resins cannot be mixed in with non-degradable resins and still retain the base resin’s properties when processed as Post Consumer Resins (PCR). Without clear labeling, this creates significant challenges for waste stream processors for sorting and for plastics reclaimers in keeping these resins out of the recycling stream.

More effective to have purity of resins for plastics recycling

Container producers and other users of PCR mixing with virgin resins use less energy and in some applications less colorant (such as when using Envision’s PRISMA™, custom color sorted PCR), because the PCR has already expended that initial energy and mixed in the necessary colorant. With the potential of non-labeled or improperly labeled bio-degradable resins being in the mix, the end product is contaminated with the bio-degradable properties, producing product that will not meet the resin property standards needed by the end user. If this becomes predominant, users of PCR may refuse the PCR product and use only virgin resins, resulting in more resins going to the landfill and more energy used to produce the virgin resins, rather than fulfilling a better use of PCRs in the recycling stream.

Let’s look at the potential quality issues IF bio-degradable plastics contaminate the PCR stream. Imagine how durable goods would be impacted. A common use of PET resins is for clothing and carpet. If the contaminated PET degrades, as it is supposed to do, you may experience some embarrassment at a party if your recycled dress starts disintegrating. For HDPE, common uses are for toys, lumber and lawn furniture. Over a period of time, these articles may lose structural integrity in the sun as the bio-degradable plastic portion starts doing its expected thing.

At this time, there is no need for concern about the quality of PCR, but it could happen if the bio-degradable plastics contaminate the PCR stream.

More stringent regulation is needed of bio/oxy-degradable resins to be included as part of a total plastics sustainability strategy. Until then, these resins must be clearly marked to avoid contaminating the PCR life cycle.

Our Position

The Litter Issue

Bio /oxy-degradeable plastics have a place in packaging or products where litter could be an issue.  How big the litter issue is depends upon your perspective.  In the U.S., litter is mostly accidental and not a method of primary disposal.  This is not necessarily true elsewhere in the world.  The great Pacific garbage patch is primarily caused by other countries dumping their trash in the sea and ocean going vessels doing the same.  Could bio /oxy-degradeables help here?  It certainly seems so, but determining what should be bio / oxy-degradeable would still be debatable.

Bio / Oxy-degradable Plastics Should Not Be Used in Bottle Applications

96% of all plastic bottles produced in North America are either PET (#1) or HDPE (#2).  These are the two most recycled plastics on the planet and the mainstay of curbside collection and deposit / return systems.  The introduction of bio / oxy-degradeable plastics into this stream will have disastrous effects on the quality of recycled resins produced from these feedstocks.  It is already a challenge for recyclers to maintain the quality of recycled resins through traditional methods without introducing materials that will degrade polymer performance by its use.  We need a persistent effort to encourage more recycling of plastics, not introduce materials that will degrade performance of plastics that are already being recycled.

We welcome any other topics you wish to see or your comments on our posts.

Need more information? Envision Plastics Vice President, Tamsin Ettefagh will be happy to discuss your comments or concerns in greater depth. Contact her at 336/342-4749 Ext 225.

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3 thoughts on “Bio-degradable/Oxy-degradable Plastics – Great Idea, But the Implementation Still Needs Work

  1. This is an interesting article, but I believe that you have “oxo-degradables” and “biodegradables” mixed up in the second paragraph. Oxo’s need light and oxygen, hence the name “oxo-degradable.”

  2. I think recycling is compliacted enough already without using plastci that look like plastics but are not. I should imagine they get mixed up with standard plastic films and make dealing with recycling of this (film) hard to deal with waste even less cost effective.

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