No series on waste management can afford to ignore the issue of plastic. Plastic is ubiquitous in our lives. It is used in construction material, for accessories and electronic gadgets, and more obviously for storage and cheap packaging.
Since plastic is cheap and versatile, its abuse presents a serious environmental menace. It is derived from petrochemicals, so is inherently unsustainable. It degrades slowly (taking up to 500 years) and in the process releases persistent organic pollutants that can be ingested by organisms in the biosphere, contaminating not just the atmosphere but also the food chain.
The MOEF released plastic waste management rules in 2011, giving us a basic framework to examine the plastic that enters our lives. Some of the salient points are:
• Plastic carry bags should not be distributed free
• Manufacturers should indicate the thickness of plastic and indicate whether it is compostable or recyclable
• Plastic carry bags should be only in white or use BIS permitted colours
• Carry bags are to be 40 microns or thicker (against the earlier 20 microns)
An interesting point in the rules has been the formal recognition of the role of rag-pickers. The Ministry requests Municipalities to constructively engage with rag-pickers for better waste management. This is important because rag-pickers have always known what we educated citizens do not: that all plastics are not the same.
The term 'recyclability' of plastic is incorrect. Recyclability implies that if we pulp and process a plastic bag, we should get something of similar strength and durability. However, plastics cannot be recycled, only 'down' cycled. So if your plastic bag is processed, in the best case, you will get a lower grade that holds less weight and won’t last as long.
This is because plastics, when compared to other material like paper, glass or metal, are more complex to process. They require a sophisticated system to separate different blends and grades in order to properly recover value.
Different types of plastics like PET and PVC cannot be processed together. This is a vital reason why responsible citizens must segregate waste at source.
Colours and additives also interfere with recycling: it is difficult to process a red toothbrush and a green bottle together even if they are of the same type and thickness.
If two exactly similar green bottles are processed together, you still have to add a neutral colour to coat the recycled plastic, which adds another layer of chemicals to the already potent mix.
Plastic bonded with another material is difficult to downcycle. Biscuits and chips use 'metalised plastic', which has a thin layer of metal. For recycling, the plastic and metal has to be separated and this is almost impossible to do without damaging both. This is why metalised plastic is rejected even by rag-pickers.
Now, we see that plastic waste management does not end with carrying a cloth bag to the store, although that is a noble first step. We should educate ourselves about the materials we use and choose those that stand a good chance of being recycled.
Our next article will examine different types and grades of plastic to help us choose responsibly.
