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(A case for removing apprehension regarding perceived environment negatives of plastics.)

Dr. A.N. Bhat, Director General
Indian Centre for Plastics in the Environment

Criteria for environment friendliness

For discussing environment friendliness of any product we need to keep a few important criteria in mind. These are (i) conservation of resources e.g. raw materials, energy, water and minimization of emission to air/water during manufacture (ii) performance superior to alternatives, help conserve resources and (iii) recyclability, biodegradability, reusability or alternative disposal methods with least burden on environment.

If one strictly applies these criteria, plastics will clearly be seen to be an environment friendly material.


Processing and resource conservation

Take the case of first criterion. Plastic processing involves mild temperatures, thereby using less energy, and does not result in polluting water or air, the way paper or jute manufacturing pollutes. It is perhaps for this reason that Central Pollution Control Board in their Guidelines for Management of Consent and Authorization (2001) has classified plastic processing under Green category while paper and jute belong to Red category. In view of this, it is difficult to understand why many times the so called environmentalists appeal to consumers to use paper bags instead of plastic bags!


Performance/weight ratio

On the second criterion, plastics out performs other substitutes. This is because of an inherent property of plastics. Their performance/weight ratio is very high. It has been estimated that for packing 500gm. of coffee one would need 500gm of glass container, 130gm of tin container, but only about 12gm in case of plastic packaging. Imagine the extent of conservation of resources by plastic. The advantage does not stop here. If we had to transport one tonne of packed coffee from one part of the country to another, one would need to transport one additional tonne in case of glass packaging, 260kgs in case of tin, while it would be only 24kgs in case of plastics. This would result in saving on fuel, wear and tear or carrier trucks, as well as that of road etc. Indirectly plastics usage as a packaging material is a great boon on environment grounds. Plastic has also prevented massive deforestation by offering wood substitutes like furniture, building material, crates etc. In fact plastics have rendered help in afforestation programnmes in a major way e.g. nursery bags, drip irrigation etc. Minor irrigation system using sprinklers (drip and minor) have been reported to help in conserving water to an extent of 40% to 70%. Plastic packaging prevents wastage of agricultural products and processed foods to an extent of 25-30%. Plastic woven sacks conserve 4 million tones of cement avoiding losses via seepage as in traditional sacks. Similarly plastic pipes conserve material e.g. 1 Km of plastic pipe uses 1.7 MT while 1Km metal pipes need 10 MT. Thus plastic enables to get more out of less, and ensures sustainable development programmes.


Recyclability and Disposal

Coming to the third criterion, viz disposal issues, it should be noted that plastics are crushable and highly compactable occupying less space in land fills. They are predominantly eco-neutral and do not leach any chemicals to contaminate soil and ground water. In fact plastic films and sheets are used for protecting lining of hazardous landfills. Some people fear that plastic being non-biodegradable can cause harm to environment. For the types of application of plastics, its non-biodegradability is an asset. In any case, total mineralisation of a solid waste is a very lengthy process requiring special anaerobic conditions and methanogenic bacteria. Newspapers/telephone directories from landfills after 40 years were readable. Similarly perishable products like waste food, raked loaves and lumber was found in landfills even after 25 years.

Plastics are 100% recyclable via various routes:

(i) Mechanical recycling by which plastics can be recycled several times into economically useful low cost products e.g., Footwear, Mats, Sewer Pipes etc.

(ii) Waste plastics are also recycled without sorting into synthetic lumber/wood products like rails, fencing, ports etc.

(iii) Plastics can be thermally recycled to recover energy.

(iv) Plastics can be chemically recycled to recover monomer e.g. engineering plastics.

In India we already recycle 60% of plastics from both industry and urban waste stream.

Briefly, let us look at a scenario if plastic packaging were replaced with traditional materials like paper, cloth, jute, metals etc. This will lead to a major penalty on the economic system. Phenomenal increase would be affected in weight of packaging (300%), volume of waste (160%), energy requirement (100%), and cost of packaging (210%). There are thus no eco viable alternatives to plastics in modern society.

If from the above analysis plastics are environment friendly, why is there so much of opposition to use of plastics from environmentalists or regulatory agencies in the country? The indiscriminate littering of light plastic bags by our people on the roads, parks, beaches and other public places results in ugly sight. Inefficient and inadequate management of solid waste in our country compounds the problem. There is thus a need to educate masses against littering, and improving solid waste management by civic authorities. This can be achieved by combined efforts from Government, Industry and Citizen groups.

Before concluding this paper, it would be useful to refer to some of the myths regarding safety issues in use of plastics, and provide factual details. It is particularly widespread in case of PVC products.


PVC and safety issues: Myths and Facts

Some people are worried that PVC may contain Vinyl chloride monomer (VCM), which is believed to be a carcinogen. Actually this link was made in the 70's. With introduction of revised production technology, since late 70's, not a single case of angiosarcoma has been identified among workers in any PVC factories. The problem has been eliminated.

Have most of our NGOs been fair in terming plastic as the main environmental pollutant while ignoring the lax attitude of citizens about littering particularly of thin plastic carry bags and absence of litterbins?

Another wide spread myth is that PVC is a potential source of dioxin. The fact is that dioxin emissions have declined by 50% since 1970 even though PVC production has more than doubled. There is also an allegation that burning of PVC results in dioxin generation. The fact is that most types of combustions produce dioxin. It is wrong to blame any specific material for dioxin production. There are reports that after a fire in a PVC recycling warehouse in Germany, dioxin levels in fire gases were comparable to the amount of dioxin found in unrestricted agriculture soil. Similarly when blood test of 26 people exposed to the fire was carried out, dioxin content did not exceed that of unexposed subjects.

PVC does not cause disposable problem in Municipal solid Waste (MSW) to the extent it is made out. Nearly 75% PVC is used in pipes, profiles and cables which have a long (50-100 years) that do not form part of MSW. About 10-15% PVC consumption is in packaging and disposal application. MSW has been less than 0.5% weight of PVC. The contribution of acid generation from PVC is less than 0.25% of the total. Major sources are sulphur dioxide from thermal power station (69%), nitrogen oxide (29%) from auto emission.


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