Are biodegradable plastic bags the answer to cutting waste?
evidence from Ireland suggests that the most effective means of
cutting down on plastic bag pollution is to introduce a tax.
Anthony Fletcher reports.
A polyethylene bag manufacturer has developed environmentally friendlier plastic bags designed with a controlled lifetime. Omniplast, in partnership with EPI Environmental Products, has acquired the rights to apply the Totally Degradable Plastic Additives (TDPA) technology in the manufacturing process of its poly bags. Plastic bags will degrade in as little time as a few months to five years when discarded as the additive accelerates the oxidation of the plastic.
The degradation process, triggered by UV light, heat or mechanical stress, occurs at a rate tailored to the buyer's requirements, breaking down over a period of months or years. Once the plastic begins to oxidise it becomes brittle and susceptible to the usual agents of degradation, such as moisture and microbes.
Plastic bags are a major source of packaging waste The problem is that they are so cheap to produce, sturdy, and easy to carry; according to the American Plastics Council, they have captured at least 80 per cent of the retail market since they were introduced a quarter century ago.
And according to Omniplast, nearly four million tons of plastic products are sent to Canadian landfills alone every year. With disposable packaging increasing in popularity - especially within the food industry - this waste will accumulate unless action taken.
Omniplast believes that biodegradable poly bags can but help. With less than ten per cent of plastic bags ending up in the recycling chain, most is disposed in landfills or in the streets accumulating as litter.
But the problem of course is that biodegradable poly bags are just a drop in the ocean, and perhaps do not address the fundamental issue of waste. Somewhere between 500 billion and a trillion plastic bags are consumed worldwide each year, and of those, millions end up in the litter stream outside of landfills.
Indeed, it has become such an environmental nuisance that countries such as Ireland, Taiwan and Australia have heavily taxed the totes or banned their use outright. Several other regions of the world are considering similar actions.
Ireland's success in tackling the problem of plastic packaging waste provides a strong argument for heavy taxation. In March 2002, the country put a 15-cent tax on plastic bags, resulting in a 95 per cent reduction in their use.
In 2001, an estimated 1.2 billion plastic bags were handed over to shoppers. But consumers in Ireland have become quickly accustomed to carrying around a reusable bag, and the plastic bags that once blighted the country are now merely an occasional eyesore.
Bangladesh also banned polythene bags in 2002, after it was found that they were blocking drainage systems and had been a major culprit during the 1988 and 1998 floods that submerged two-thirds of the country.
Taiwan and Singapore are also moving to ban free plastic bags and in South Africa they have been dubbed the "national flower" because so many can be seen flapping from fences and caught in bushes.
There have been dissenting voices. Fiona Moriarty, director of the Scottish retail Consortium (SRC), believes that the experience in the Republic of Ireland has demonstrated that a tax on plastic bags has unintended consequences.
"Consumer demand for paper bags in high street stores has led to severe environmental costs in terms of transport and fuel usage as they take up ten times the storage volume of plastic bags," she said.
"A major retailer in Eire reported an increase in sales of plastic bin liners of 70 per cent and others reported increases of 20 per cent in sales of black bin bags, as plastic bags were less readily available for re-use."
While countries such as Scotland continue to debate the merits of introducing such a scheme - Liberal Democrat MSP Mike Pringle introduced a member's bill for a levy last year - it seems highly unlikely that North America will ever do so. The American Plastics Council claims that such a tax in the US would cost tens of thousands of jobs, and echoes Moriarty's argument that it would result in an increase in energy consumption and landfill space due an increased reliance on more expensive paper bags as an alternative.
Whether this would happen in practice or not is debatable, but industry and consumer opposition would probably prove too great. For many countries, biodegradable poly bags may therefore be the best option available, and could be the plastic packaging industry's saving grace.
