‘Biodegradable’ plastic will soon be banned in Australia. That’s a big win for the environmentPosted on March 15, 2021 by DrRossH in General, Plastic Waste News
The obvious answer then, is to eliminate problematic plastic altogether, as the National Plastics Plan is attempting to do, and replace single-use plastics with reusable alternatives.
We agree with most of what was said but thought a few points could do with an embellishment. In the USA under the FTC Green Guide people/companies cannot use the Biodegradable plastic term without qualifiers. For the same reasons as were pointed out, but then in a few places the paper covered biodegradable plastic in one broad brush saying they all had the same properties. This is not so. What we need to be saying when we say biodegradable is how is it biodegradable and where is it to be disposed. This is what the Green guide stipulates which we think is the right approach.
In this paragraph below it covers two separate thoughts but being in the one paragraph they read as one.
“Biodegradable plastic promises a plastic that breaks down into natural components when it’s no longer wanted for its original purpose.” This is sort of correct, but they break down when disposed to an active environment. This explains why the don’t break down in the oceans or in litter environments. Biodegradable plastics do break down and that should be acknowledged by saying where they will break down. Landfill-biodegradable plastics (example link) will biodegrade (in multiple year time frames) under aerobic and anaerobic conditions in microbe rich areas such as modern landfills. We have verified this many times as well in lab tests. Home compostable plastics will break down quite fast (months) in active home composts which are aerobic or in modern landfills (aerobic or anaerobic). We have also verified this.
“The idea of a plastic that literally disappears once in the ocean, littered on land or in landfill is tantalising — but also (at this stage) a pipe dream.” This is also true but not necessarily related to the sentence above.
“A major problem with “biodegradable” plastic is the lack of regulations or standards around how the term should be used. This means it could, and is, being used to refer to all manner of things, many of which aren’t great for the environment”. wE agree whole heartedly and until Australia catches up, this is going to continue.
“So it’s best to avoid all plastic labelled as biodegradable. Even after the ban eliminates fragmentation — the worst of these — there’s still no evidence remaining types of biodegradable plastics are better for the environment.” Here we would offer different comments. If the type of biodegradation was stipulated then it would be good. We can also separate out benefits for the environment into benefits on the manufacture side or the disposal side. For the disposal side then some landfill-biodegradable plastics and Home compostable plastics are better options that doing nothing. Most of these will go into a landfill (where most plastic goes) and over time they will biodegrade down. That is a better option than sitting there for centuries. See methane comment later. Another comment on the disposal issue. While landfill-biodegradable plastics are mainstream recyclable, home compost plastics are not. They have to be discarded, so once their useful ‘reuse’ is finished they have to go to waste (at the moment). So that is a disadvantage of Home Compost. On their manufacture side, are they any different to produce than a conventional plastic item?
In the compostable section you wrote
“Even those certified as “home compostable” are assessed under perfect lab conditions, which aren’t easily achieved in the backyard”. This is written as quite a negative implying statement. When it need not be. Home compostable will biodegrade very fast when tested under lab anaerobic (which is tougher than aerobic) landfill conditions. 3-4 months. Even in our own tests in back yard compost bins the home compost biodegrades way quite well in a few months. If we want the public to get educated and move away from conventional plastics, then we have to give them options. It would seem that home compost products (plant based + PBAT) do offer better solution for the environment over all. Like was said above, there in no one solution for all environments and there might never be, but we can pick the best of the available options. Landfill-biodegradable does offer long term benefits over Home Compost, (biodegradable, but slower than Home compost, and recyclable) but from a general consumer point of view (Which the Green Guide recommends), they expect the plastic to biodegrade away in a few months. Believing that, then Home Compost is more suited to that understanding.
“Finally, if you don’t have an appropriate collection system and your compostable plastic ends up in landfill, that might actually be worse than traditional plastic. Compostable plastics could release methane — a much more potent greenhouse gas than carbon dioxide — in landfill, in the same way food waste does”. This we found too to be over negative and for the wrong reason. As compostable plastics are getting increasingly promoted by the Fed govt more and more we need to always differentiate Commercial compost from Home compost in these type discussions. They have very different characteristics in some environments. Modern landfills will capture methane combust it to generate renewable energy. Energy from landfill methane is a lower CO2 emission intensive operation that generating the same amount of energy from coal. So that can make it quite a plus. (Some people call this part of a circular economy) Letting home compostable plastics go to landfill can be a positive thing to allow some of its internal energy be reclaimed. Not so for Commercially compostable plastics as they don’t biodegrade in landfills, (too cold).
Lastly a point to consider is, at the moment our society is so hooked on plastic, that it will take decades to effectively move its behaviour. There is no infrastructure to deal with it, the labelling system for consumers is very limited, too many plastics and coloured plastics are being used which are not recyclable. Also there this little education to the public to drive them to change their behaviours. This alone, would be very expensive and take a long time It will need state and federal real legislation. The current impending National Plastic Ban is great to get the discussion going on this problem, but is relying on voluntary opt ins by industry which if this follows other history cases on voluntary changes, then it will be ineffective and in 5-10 years’ time we will be having another discussion like this. And it is only on packaging which is not a large portion of every day plastic use across Australia. The Victorian State plan also a good start and has more definite goals of actually banning some items. The items they list though are a small fraction of the littered plastic items. (We are just finishing 5 year survey, sampling every other day) on littered plastic and those items they list are about 3-4% of the plastic collected). So all this points we are going to be using plastic and lots of it, for a long time yet. Hence the use of landfill biodegradable or home compostable plastics now will be a very good stop gap change. Both are biodegradable in landfills, where our waste is going now, plus landfill-bio is not precluding recyclability.
“The obvious answer then, is to eliminate problematic plastic altogether, as the National Plastics Plan is attempting to do, and replace single-use plastics with reusable alternatives.” We fully agree here, but there will be a lot of pushback from industry for many years delaying any action. NSW still doesn’t have a plastic bag ban, Vic still doesn’t have a CDS in place are examples of this delaying.
On an aside, not related to this paper. On recyclability, that term too is getting marred by the government. They seem desperate to claim any reuse of plastic as ‘recycling’. Using plastic to make roads and concrete paths is not recycling in a circular economy sense. It is more of a pigtail recycling. The plastic gets one more use then it is locked away in a form that it is highly unlikely to be reused again. This one other use is just delaying the inevitable of going to waste. We need to be encouraging the government to push for PET and LDPE full recycling (into other useful plastic products) and avoid other plastics that can’t be used in a circular economy. Australia is a importing country so this will be very difficult to do however.