There are a number of plastic products on the market that claim to be compostable, biodegradable or degradable. These claims, if not confirmed or supported by independent established internationally recognized standards or certifications eg; European Norm EN13432, EN13432 or ASTM D6400 printed on the products or bags, are most likely FALSE. Materials that do not comply or are not certified to these independent standards cannot use these symbols or logos. These bags and films are in fact almost entirely regular plastic. They contain a small percentage (approx. 3%) degradable additive which is mixed in with the plastic, and when the additive breaks down it causes the plastic to fragment, but the fragmented plastic that becomes difficult to see due to the smaller particle size does not mean it has biodegraded or composted, it is still there. The plastic (polymer) fragments or plastic dust act like a magnet (plastic usually carries a static charge) for toxins, dioxins and other pollutants. The fragments and plastic dust will find their way into our soils, water systems and runoff into the sea contaminating the environment and our food chains.
Plastic debris such as packaging has well-known effects on sea life, strangling and overpowering the stomachs of birds, mammals and fish. However it is the smaller particles reducing in size with time that has created a more serious situation. Japanese Scientists (study released 2001) found that hydrophobic pollutants accumulate on plastic pallets in the ocean.
Relatively little is known about the even smaller microscopic fragments of plastic that have previously gone unnoticed as they are not readily visible. They have been found floating in the ocean, settling on sea beds and washing up onshore with unknown consequences for marine ecosystems.
Regular or traditional ‘Plastic’ is not biodegradable, over time it just breaks into smaller pieces. Every piece of plastic ever manufactured still exists, according to Dr Anthony Andradean expert on the breakdown of plastic in the marine environment. Plastic materials with degradable additives only make this serious problem worse.
This is not innocent confetti and dust becoming hidden as it reduces in size, but rather very effective toxic accumulators contaminating the food chain and ecosystems.
The degradable additives also contain chemicals and heavy metals like; Cobalt, Manganese, Iron, Zinc and Nickel in high concentrations.
There is no country in the world that allows oxy-degradable products into their composting facilities.
A large NZ commercial composter completed this year (2010) their own independent composting trial of a range of different oxy-degradable bag brands. The bags were subjected to the standard full term 180 day composting cycle and the ideal composting conditions; all bags oxy-degradable bags emerged unaffected at all and as good as the day they went in.
So what are their 'end of life' options: they have a negative effect on recycling, they will not compost, the additives have proven toxicity persistence, they may fall apart but not degrade or biodegrade, they are mostly land-filled along with other plastics and even worse they are discarded as litter in the belief that they will degrade. So in reality they have no benefit in any situation or waste stream.
Consider just the recycling stream for example: "The facts are very clear," reports David Cornell, the Technical Director from the Asso¬ciation of Postconsumer Plastic Recyclers (APR), Washington, USA. "The degradable additive concept effectively renders the product using the additive non-recyclable. Many recycled plastics are used to make durable goods. Failure of these next-use products, such as carpets or piping, could range from distressing to tragic." Oxo-degradable or pro-degradent, (Oxo-fragmentable), films or bags entering a recycling or composting waste stream will contaminate the systems.
It is important that Compostable bags or films do not take longer than other organic matter to compost so not to effect the operation of a commercial composting facility. There are international recognized performance standards covering compostability and biodegradability including ISO 17088, AS4736, EN13432, BS 13432, ASTM D6400.
Disintegration of a product into thousands of tiny particles simply transfers the problem from a visible contaminant or pollution to an invisible one. Not all that long ago, no one knew about the harmful effects of asbestos fibers, but now we do. We do not know what harmful effects will result from the toxic accumulating plastic particles, building up in the environment, contaminating farmland (from oxy-degradable Mulch Films), the soil, waterways, the water table, the sea, the food chain and ecosystems, so we should not produce them.