PLA - not for the yellow bin

PLA or Poly Lactic Acid is a relatively new polymer derived from natural materials such as corn starch, tapioca or sugar cane.  It's used as an alternative to conventional oil based polymers in a wide variety of applications including food packaging.

Unfortunately within Christchurch, PLA cannot be considered recyclable or compostable through the kerbside collection service.

One of the key drivers for the use of PLA is its bio-degradable properties under the right conditions.  When placed into a composting facility or a domestic compost heap, the PLA will degrade over time.  When left exposed to natural elements, the PLA will also degrade but over a longer period. 

Despite the advantages of PLA, there are also some significant disadvantages.

One of the most significant disadvantages is identifying the material within the waste stream.  PLA has been engineered to look the same as its conventional alternatives meaning even to the trained eye, it's difficult to separate.  Therefore, ensuring PLA does not contaminate other plastic grades can be very hard.  Contamination within another sorted plastic grade can mean a customer has the right to ask for a reduction in cost or reject the shipment altogether.

Another factor is the volume of PLA currently present in the waste stream.  In Christchurch we are collecting between 15 and 20 tonnes of clear PET bottles per week - enough to fill a 40ft container.  We estimate at present we are receiving 500 kgs per month of PLA meaning it could take 3 years to fill the same 40 ft container.  However, to begin collecting PLA, we would require a re-engineering of our Material Recovery Facility where we can divert PLA into a dedicated collection point.

Compounding this, the recycled PLA market has a low commodity price and presently costs more to ship a container of PLA overseas to a recycler that the actual material is worth.  Therefore it is not financially viable for EcoCentral to begin sorting PLA for recycling.

For information about the commercial composting facility, please visit the CCC website at http://www.ccc.govt.nz/homeliving/rubbish/kerbsidecollection/organics/index.aspx or the Living Earth website at http://livingearth.co.nz/faq/christchurch/

With the above in mind, the only places where PLA can be disposed of in Christchurch is within domestic compost heaps or the Red Bin kerbside collection service.

We ask than any manufacturer who is seeking to use PLA or another new packaging material consult with their local waste stream contractors to understand the impact.  By understanding what happens once the consumer places the empty packaging into the right bin can the complete chain of custardy be fully understood.