I recently bought some apples and spotted an intriguing little logo on the back of the plastic packaging. I look carefully at just about all plastic packaging these days in an attempt to identify what type of plastic it is (and therefore how recyclable).What I found was a bit different to what I was expecting. Below a little logo was a website reference, www.degradable.net. So, off to the website to find out what this was all about.
It turns out that these smart guys have developed a low cost additive for polyethylene and polypropylene which causes the plastic to break down into a biodegradable form (the long plastic chains break down into shorter chains which can then be accessed by micro organisms which break them down to carbon dioxide and water. You can read the full details on their site). Astrapak are the South African suppliers of these plastics. There are also some alternatives to the d2w process which make use of light sensitive, or starch additives.
The great benefit of this is that plastics which are disposed degrade much faster (they can be set to degrade after 60 days or up to 6 years later). One of the issues that this technique creates is that it impacts on recycling. The degradable plastic can be recycled, but in their words, "..there are many different and complex permutations of both input feedstock and output materials which need to be individually considered," i.e. it's complicated. It seems like it is easier to create recycled material that is degradable, while creating non–degradable recycled products is trickier.This seems like a big disadvantage, but according to the EIA only 5% of plastics produced in America are recycled (I am sure that figure is much lower for South Africa). That means that up to 95% of the plastic produced ends up in land fills, water ways and generally strewn around the country side. At least using degradable plastics means that they will have a smaller, and shorter impact on our environment.
I am sure that a lot of people would rather argue the case for bioplastics. Personally I have always been sceptical of the benefits of bioplastics (and biofuels), mainly due to the pressure they place on food prices. More recently there have been some studies revealing that biofuels may damage the environment more [1][2] than emissions due to conventional fuels (bioplastics come from the same process, and therefore have a similar impact). So bioplastics may not currently have all the benefits that they claim.Degradable plastic is a great product due to its reduced impact on the environment, but we do need to examine how we use and dispose of plastics. The reality is that plastic feedstock (oil) is a limited resource [3] and we need to use it wisely. Biofuels and bioplastics may not be the panacea that many people have hoped for. Only a small percentage of plastics are recycled. Plastics that are recycled are typically used to make other products rather than replace the recycled product, which means virgin feedstock is constantly required.
The real long terms solution is to reduce the amount of plastic we use, as well as reuse it as much as possible, and to continue recycling when a product reaches the end of its lifetime. So, in my mind, the question is this: how do we create plastic products with longer lifetimes? That is what really needs to change.
References:
[1] "Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change" by Timothy Searchinger, et al.
[2] More on the negative impacts of biofuels.
[3] According to Waste Watch,
"It is estimated that 4% of the world's annual oil production is used as a feedstock for plastics production and an additional 3-4% during manufacture."
Oil is not being imported to make oxo-bio plastic bags. It is being imported to make gasoline, and the bags are made from a by-product which used to be flared-off at the refinery and wasted.
ReplyDeleteHi Duncan
ReplyDeleteInteresting article indeed. I think SA has come a long way in terms of plastic bags. Since introducing prices at the shops most people opt to recycle their bags by re-using them.
I hardly see any plastic bags littering the streets anymore.
It's at least a small triumph worth mentioning.
I think that the plastic bag legislation is good, but I'm a little unconvinced as to its efficacy. I am very sure that it has reduced plastic bag waste, but there are quite a few things that I still just don't get:
ReplyDelete1) Why do most people that I stand behind in a queue buy plastic bags?
2) Why do they sell them for so cheap? I think retailers should penalise people by overpricing plastic bags (like R10 a bag)
3) Why do they keep putting my stuff into those silly little plastic bags even when I ask them not to? Is that even allowed (I've only seen it in the Western Cape).
I would be interested to know what the stats are on the reduction of plastic bags due to the legislation.
Obviously, plastics shopping bags are also only a small amount of the plastic that is in circulation. Just about every item in stores is somehow packaged in plastic, and most of that makes its way to land fills (even though a lot can be recycled).
I would really like to see a move towards less packaging, and plastics that are more reusable (reuse beats recycling any time).
Recycling plastic and reusing it rather than dumping into a land fill is a better solution than simply throwing it away.
ReplyDeleteWe recycle plastic for automotive parts and then paint the plastic automotive parts which reduces vehicle weight and provides a nice interior.
Indeed many people are skeptical when it comes to these degradable plastics. We all know that not all plastics can be recycled. It is not as easy as processing paper like what http://www.sanantonioshredding.com do. Plastics come with a more complex way of processing and recycling. A long term solution would be better in order to save what we have left on earth. Going green does not simply come with an over night solution. What we need is to have a long term solution that will make a difference for the environment.
ReplyDelete