Thursday, November 12, 2009


There was a time during good old days when shoppers use to carry cloth or jute bags to bring groceries from stores and these shopping bags are permanent part of a house hold, washed frequently. It is common sight to see such bags with many people coming to the market for purchasing different items from various shops. Advent of plastics has changed this scenario for good and plastic bag industry has been able to manufacture very thin, single use carry bags at low cost enabling the sellers to offer their products in such bags free of cost. Bags with less than 20 microns thickness but with unparalleled strength are to day available and their cost is just a fraction of the cost of the materials that it can carry. According some estimates every minute about 10 million bags are produced, most of which are of single use type ending up in the garbage and annual production can be as high as 5 trillion bags. The world per capita consumption works out to 1000 bags per year. If plastic bags have attained such a preeminent position in human lives, there must be strong reasons and if they are to be eliminated, as is being contemplated in many countries, then also there must be strong reasons to justify such a strategy.

Most of the plastic bags that is seen to day are based on polyethylene (PE) polymer derived from natural gas and therefore one may have strong reservation regarding dependence on an exhaustible fossil fuel source. Long time, about 700-1000 years, required for degradation of PE in nature and environmental contamination potential naturally make PE an undesirable material for use in manufacture of carry bags. Indiscriminate littering with PE bags create serious environmental problems for the infrastructure as well as other forms of life. The frequent urban flooding episodes have been attributed to discarded plastic bags choking drains and water ways, preventing free flow of water from flooded areas. Though PE bags can be recycled with ease, currently less than 1% is actually recycled in practice. Use of PE bags, made from non-food grade resins, for food contact application, can cause serious health hazards. If plastic bags are to be avoided there must be a decent alternative with much better credentials.

Paper, jute, cotton fabrics etc have been suggested as alternate options. Paper can never be a suitable substitute because of its links to deforestation and more than double the energy required for its production. Same is true with jute and cotton fabrics but they can still be acceptable as long they are reused several times. Reuse can still save plastics from oblivion and the problem of its biodegradability can be addressed in a different way. The ability of plastics to be compacted into small sized bundles offers the possibility of their use in land fills, construction industry and for road building for which low biodegradability is a plus factor. Also under development are new plastics with biodegradable characteristics. Polylactic acid is an example though it is also being criticized for the uncertainty regarding its recyclability. Incorporation of additives in PE to provide a UV and/or biological mechanism to degrade in 6 months to 2 years is also under development.

If recycling can be a viable option for PE bags to continue to serve humanity, what can be done to prevent people from throwing them away after single use? Banning their use, as being done in some states in India, may not be a practical solution since enforcement of such ban is neither practical nor cost manageable. Latest suggestion to come from some NGOs is to financially reward the shoppers for returning plastic bags whenever they make future purchases but who will bear the economic burden is not clear. Why should the retailer pay it from his pocket, unless he is a socially responsible person caring for the planet? Probably government may intervene by rewarding the grocer when used plastic bags are redeemed by designated agencies at a rate adequate to reimburse the amount paid to the consumers. The prevalent low price commanded by used plastic bags does not motivate many consumers to take the trouble of returning the used bags. Rewarding the consumer at @25-50 paise per used bag may be more appropriate for which governments in the state and the center must make budgetary provision. It looks like there is no realistic alternative to plastics and one has to learn to live with them, making best use of technological innovations to alleviate some of the perceived problems.       

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