Movie buffs will remember the iconic 1967 Hollywood movie, The Graduate, in which Ben, played by a very young Dustin Hoffman, is given career advice by a friend of his parents at his graduation party. “Plastics”, he is told, “there is a great future in plastics.” Fifty years later, the spread of plastics bears out the accuracy of that prediction. But our message today would be, “plastics are all pervasive and very convenient but we need to worry about food safety, design for recycling, and safe management of non-recyclable plastic waste to ensure environmental protection”.
Plastic is a synthetic polymer, deriving its name from the Greek word plastikos, which means “fit for moulding”. It was invented in 1869 by John W. Hyatt, responding to a New York firm’s offer of $10,000 for anyone who could provide a substitute for ivory. The subsequent 150 years have seen chemical companies develop many new polymers and many different types and grades of plastic.
This inexpensive, light, and versatile product enters our everyday lives in numerous forms ranging from bread wrapping, magazine and invitation covers, and packages of many ordinary consumption items at one end and also as part of television sets, refrigerators, cars and aircraft at the other. The problem is that plastic does not decay. It sticks around in the environment as deadweight. Recycling of plastic is, therefore, extremely important, and waste management systems and product design explicitly need to facilitate plastic recycling. Worldwide, only 14 per cent of plastic is collected for recycling, while the rest stays in the environment causing pollution both on land and in the ocean.
As regards food safety, consumers need to understand which plastics meet the criteria. Among the many choices available, while PET (Polyethylene Terephthalate) and HDPE (High Density Polyethylene) are generally considered safe in not leaching any chemicals, there are concerns with regard to PVC (Polyvinyl Chloride) which need to be addressed. The Plastic Waste Management Rules 2016 Sec 4(b) explicitly state that only virgin plastic is to be used for storing, carrying, dispensing or packaging food stuff which is ready to eat or drink. However, enforcement remains a challenge.
Recycling of plastics is not always economically and/or technically feasible. Composites like roofing sheets, bonded rubberised coir mattresses, etc are really difficult to recycle when the components are hard to separate. The solution lies in instituting extended producer responsibility laws under which their take-back and disposal by manufacturers should be mandatory.
Plastic sachets used for packaging of snack-foods like potato chips can also not be recycled. These sachets are composed of three to seven thin layers of different plastics glued together to keep air and water vapour out and retain odours and freshness. These could be recycled if all the layers were thermoplastic (like polythene and polypropylene) which soften into lumps and granules upon heating. They become non-recyclable because of an inner layer of thermoset plastic (nylon or polyester) which does not soften on heating but chars instead, blocking the filter screens and requiring the shutdown of heating equipment every few minutes. Even plastic-coated paper cups and/or stationery pose problems for recycling.
Appeals to snack-food packagers to use recyclable multi-films are often countered by the argument that the new (non-recyclable) material extends the shelf-life for snack-foods from six months to one year. But should we want one-year-old biscuits or chips at the cost of a city littered with uncollected food sachets? Moreover, the cost of collecting and transporting this light fluffy waste to an energy-recovery plant exceeds any possible gain from energy recovery.
Section 9(3) of the Plastics Waste Management Rules 2016 requires the phase out of non- recyclable multi-layered plastic by March 2018, while Section 17 requires manufacturers, producers and users of non-recyclable packaging to either pay municipalities for the cost of managing such waste, or arrange to take it back and manage its disposal themselves.
India has had a very long take-back experience of glass bottles for beer and soda-water. Shopkeepers would give a discount on new purchases if old bottles were returned. In the US, there is a printed refund value (different for every state) of 5 to 10 cents for return of aluminium cans, glass bottles, PET bottles and containers of soft drinks. Unfortunately, hardly any Indian city has actually taken advantage of our highly beneficial Rule 17. Municipal corporations can ask all major snack-food brands to provide the city with equipment for shredding snack sachets into 2-4 mm tea-powder-like flakes and for transport of the shredded flakes to hot-mix plants. In our October column, we had highlighted how plastic waste can be used for strengthening roads by adding such flakes to hot stones to form a baked-on polymer primer coat. The excellent bonding with added bitumen gives 2-3 times longer life to tar roads.
PET bottles have enjoyed high recycling value for making into flakes and then fibre, after removing bottle caps, rings and labels, and sorting by colour. Here too purity of the collection stream is the key. At one time, almost all PET bottle-waste from around the world ended up in China. Some years ago, US anti-dumping duty on Chinese T-shirts and knitwear made from recycled PET-based fibre caused a crash in the price of PET bottles for waste-pickers in India. It remains to be seen what will happen with the recent cutback on PET bottle imports by China.
PVC was one of the earliest plastics to be invented, but is now banned in many cities, states and even countries. It is used in water pipes, wiring cables and also beverage bottle labels, flexes, etc. It contains 57 per cent chlorine by weight, which like other chlorine-like (halogenated) plastics, releases deadly dioxins and furans when burnt. The National Green Tribunal has now asked the Ministry of Environment to consider and pass rules phasing out short-life PVC.
Major short-life PVC items like PVC hoardings and banners, flex and posters are almost invariably burnt in the open in Indian cities and contribute heavily to air toxicity. These items are largely imported from China which has banned their use in China but allows the same to be produced and exported to countries with lax environmental rules.
Another troublesome waste is expanded polystyrene, known more generally as thermocol which is a brand name. This is widely used by packaging industry for packing large items like TVs and tiny ones like cell-phones. Though theoretically recyclable as polystyrene, here too its light weight makes collection and transport for recycling and even take-back uneconomical. The West and Far East have solved this problem by switching to wonderfully creative and recyclable alternatives: Moulded papier-mâché, folded cardboard, expanded paper, bubble-wrap, air bags, compostable “peanuts” for loose-fill packaging and much more.
The plastic menace for Indian cities is compounded because of their generally poor state of solid waste management and the poor infrastructure for sewerage and stormwater drainage. Developing eco-friendly consumption habits such as avoiding disposable catering items and using washable cups and plates instead, will make a difference, but plastics will continue to play an important role in our lives. A sustainable way forward is to minimise consumption of disposable/single use plastic items, create awareness about the use of appropriate grade of plastic for different purposes, and emphasise the importance of recycling and reusing plastic.