What the heck is PLA? Is biodegradable the same as compostable?  How do I actually compost this thing when I’m done?

All the questions you wanted answers to and some you didn’t even know to ask.

What are plastics?

Typically Polymers and other substances, usually synthetic. Most commonly derived from Petrochemicals. However, an array of variants are made from renewable materials such as Poly Lactic Acid from corn (which can be certified compostable).

Why is plastic packaging a problem?

In developed economies, around a third of plastics produced are used in packaging. After being discarded as waste it has an extremely slow decomposition rate.

What materials are compostable?

Plant material, Food waste, Wood, Cardboard, Paper, certified bio-plastics such as PLA, CPLA and certified plant starch-base materials (containing a % of petroleum-based resins for plasticity).

What is PLA, CPLA?

Poly Lactic Acid is a plant-based material, often clear, that performs like PET plastic but can be composted. Crystalized Poly Lactic Acid is a more heat-resistant version of PLA.

Why reduce single-use products?

Single-use products, like lasting products, take energy to make them energy from renewable (grown), finite (extracted) or waste (re-purposed) resources. A renewable source may not also be sustainable since fast grown mono-crops can deplete soil and replace food crops. Single-Use products spend more of their life as ‘waste’ than useful.

Why choose compostable food packaging over conventional plastic or even recyclable?

Recyclable material needs to be clean to avoid becoming landfill. Genuine compostable material with food, collected into a commercial facility (or if it can be home composted), becomes soil.

What is the difference between degradable, bio-degradable and compostable?

“Degradable is a chemical process that creates many small fragments of the original material.” Degradable products are oil-based with an additive to trigger the chemical process of degradation. They are not biodegradable or compostable. Degradable materials result in smaller fragments of oil components leaving behind the same amount of plastic dust. *Degradable materials require specific UV conditions in order to break down and will remain intact when composted or buried in landfill.

“Biodegradable may not necessarily be certified for composting and will break down eventually and only under certain conditions.” Biodegradable refers to a process of biological breakdown by microorganisms like bacteria, fungi and enzymes. Under the right conditions and in the presence of micro-organisms, biodegradable material can be ‘eaten away’ leaving behind only natural constituents of biomass, carbon dioxide and water. These resulting natural materials can be safely re-absorbed back into the earth.

*This process is unlikely to occur in landfill and the right conditions may not be present for biodegradable materials loose in our environment.

“Compostable means able to biodegrade under controlled conditions within a certain timeframe to produce a compost soil product.” Compostable (certified) refers to the biological breakdown and recycling of this type of ‘biodegradable’ material within an ideal composting environment with the right mix of other elements and specific heat and moisture conditions. The compost product contains almost no toxic residues.

*Decomposition of such materials requires other resource inputs, adds rich nutrients to the soil and can be a great fertiliser for home gardeners and farmers.

How do I know if it’s genuinely compostable?

New Zealand hasn’t adopted standard labelling of compostable product yet. Good news! Use this catalogue to find product certified to international standards (for no toxic reside in the compost end-product), tested in our composting unit at Xtreme Zero Waste.

Commercially vs Home Compostable products?

Certified Commercially Compostable, means the item is capable of undergoing biological decomposition in a commercial composter within 12 weeks, leaving no toxicity in soil. Certified Home Compostable, means under home composting conditions the item is capable of undergoing biological decomposition (time-frame dependent on conditions).

Commercial vs Home Composting sites?

Commercial composting facilities provide the ideal and best composting conditions, like Raglan’s Industrial-scale Hot Composting Unit at Xtreme Zero Waste. Due to the comparatively small volume of waste involved, the temperature in a garden compost heap is lower and less constant than in an industrial composting environment. Composting in the garden is a more difficult and slower-paced process.

What does Certification to a Standard mean?

The European Standard (EN 13432 – 2006) is the most widely recognised, with the American Standard (ASTM D6400 and Australian Standards (AS 4736 – 2006) based on it.

The Australian Standard includes in addition, a set of eco toxicity tests (worm test and plant growth test), not included in the European or American Standards. This ensures when compostable material breaks down within a composting environment, it does not negatively affect the worms that consume it or the health of plants that are subsequently grown in it.

As a consumer, how do I properly discard of compostable packaging when I’m done?

For compostable packaging to be composted, it needs to be separately collected (like food waste) to be added into our our local Hot Compost Unit. We need to know contamination will be low. Once our local food businesses offer just compostable take away packaging we can plan collection and apply for resource consent to compost packaging with our local Food waste collections.