Fecha: 10/12/2008
Fuente: www.thenational.ae/
Plastic problem all wrapped up?
The Lulu hypermarket
chain plans to start using biodegradable plastic carrier bags before
extending the plan to other forms of packaging. Jaime
Puebla / The National
Strong, durable, waterproof and flexible,
plastic is pretty fantastic. Unfortunately, it has a major drawback: it
takes between 400 and 500 years to decompose, and 80 per cent of plastic
packaging is used once and then discarded. Plastic, while useful, has
become a scourge of environmental and animal- welfare advocates across the
world. But what if plastic could be made to degrade more quickly? This is
what a UK company, Symphony Environmental Technologies Plc, claims to have
done with the creation of a new additive to plastic, d2w.
D2w is added to the raw polypropylene or
polyethylene pellets in the plastic production process to create end
products with a defined lifespan. This means that they have a period of
usability before the plastic weakens, fragments and ultimately disappears.
For a plastic shopping bag this may take between nine months and one year.
For agricultural film, the lifespan can be preset according to the
farmer’s requirements. These plastics are called “oxo-biodegradable”
because they require oxygen to break down into carbon dioxide, water and
some biomass.
Plastic is made up of carbon and hydrogen
atoms bound together in long, entangled chains that give it its strength.
While d2w’s exact chemical make-up is guarded with the same secrecy as
Coca-Cola’s recipe, it consists of metal salts that act as catalysts for
the oxidation process by weakening carbon bonds and reducing the molecular
mass of the material to the point at which oxidation can occur. Oxygen
atoms then bond with the hydrogen to form water and with the carbon to
make carbon dioxide. Micro- organisms also help to consume the carbon and
hydrogen.
Symphony Environmental, through its
UAE-based agent, Eco Polymers, hopes to supply d2w across the Middle East.
They already supply nearly all the large plastic producing factories.
These factories are then able to provide their clients with degradable
plastic bags. The Abu Dhabi Cooperative and Dubai Municipality are using
them already, and the LuLu hypermarket chain has just made the decision to
use d2w in its bags.
Peter Lonsdale, the retail operations
manager for LuLu in Abu Dhabi, describes the decision to use
oxo-biodegradable plastic bags as “part of our corporate and social
responsibility. We can still offer carrier bags and help the environment
at the same time.” He adds that LuLu is considering bringing in a “bag
for almost life” containing d2w that would last for three years. At the
end of the bag’s life the customer could exchange it for a new one.
“We don’t want to stop at carrier bags
either. We will look at packaging: milk cartons, plastic packaging and
cling film. This is the start of a long journey for us. More education is
needed in the UAE regarding the environment. This is part of our
responsibility as well: to reuse, and use less, carrier bags.”
For the plastics manufacturers, the only additional cost is d2w itself.
And Symphony Environmental’s ambitions are not confined to the Middle
East. As Winston Pryce, general manager of Eco Polymers, explains, “our
aim is to get d2w into every kilo of plastic that is made”.
While there are many who have called for a
total ban on the production of plastic, few have offered a suitable
alternative. Mr Pryce is clear that “there is no economic or
environmental advantage in paper.” He suggests that we look at the
environmental impact of producing paper and jute bags from beginning to
end because “a paper mill uses huge quantities of water, huge quantities
of electricity, huge quantities of chemicals”. Furthermore, “a paper
bag of equivalent strength [to plastic] will be at least 10 times as thick
and heavy, so the logistic cost will be higher – more ships, more
lorries.” As for jute, he argues that using scarce arable land to grow
jute rather than food in times of food scarcity is not a sensible
allocation of resources. In addition, both paper and jute produce methane
when they degrade, which is 20 times more powerful as a greenhouse gas
than carbon dioxide.
Plastic, on the other hand, can be made
from naphtha, a by-product of oil production. Any naphtha not used to make
polyolefins is flared off as waste at the refinery. Mr Pryce says it
isn’t really very “green” to import jute to make bags when plastic
can make use of a material produced in abundance in this region.
However, plastic made with d2w is not the perfect solution. While the
plastic degrades, it will fragment. Above ground, where the plastic can be
oxidised, this process may take just weeks. At a landfill, it could be up
to two years. As additional refuse is placed on top of a d2w bag, the
oxygen supply gets cut off, possibly at a stage when the bag is only
partially degraded into fragments. Some scientists are concerned about the
potential danger to the environment and animal life of such plastic
fragments persisting in the environment and, some claim that even
microscopic fragments of plastic in the sea pose a threat to marine life.
Producers of biodegradable bags made from
maize or wheat starch argue that oxo-biodegradable bags should not be
called biodegradable, as they do not compost as quickly as their products.
The Oxo-biodegradable Plastics Association (OPA), the chair of which is
Symphony Environmental Technologies’ chief scientist, agrees that it is
unacceptable to have plastic fragments in the soil. However, it argues
that by this stage the oxo-biodegradable bag no longer has the properties
of plastic and will be “bio-assimilated”, meaning that it will become
part of the environment just like “straw, leaves and twigs”. Mr Pryce
adds that a fragmented bag will take up less room in a landfill and will
have spilt any organic matter that may have been placed inside it.
Significantly, the OPA maintains that “oxo-biodegradability is not a
disposal option” but aims mainly to address the plastic litter problem.
“The main benefit of oxo-biodegradable [bags] is not for plastic waste
that gets into landfill, but for plastic waste which gets into the
environment, where it will accumulate for many decades.” Other
degradable plastics, such as those with a starch base, have their own
drawbacks. They cannot be recycled like their oxo-biodegradable
counterparts, and when they degrade they emit methane.
D2w could be seen as encouraging a shift in
attitude from “reduce, reuse, recycle” to “use it once or twice and
watch it disappear”. Oxo-biodegradable bags can be recycled with other
plastics, but the fact that they will degrade could absolve consumers of
their duty to dispose of plastic responsibly. If the bags are not recycled
and allowed to degrade, there will be associated carbon dioxide emissions.
Of course, degradable carrier bags can be
reused by the consumer, but only for a limited period. Symphony can, if
there is the demand for it, produce tougher, washable, fabric-like bags,
with a d2w-controlled lifespan of five years, such as those contemplated
by Lulu Hypermarkets. This would encourage a sensible approach by shoppers
towards consumption and disposal of plastic. The demand needs to be there
first: shops need to believe this is what their customers want.
Bags with a limited lifespan are, according
to the OPA, “a low cost insurance against the accumulation of plastic
waste in the environment”. The Emirates Environmental Group (EEG), a
non-government organisation, while welcoming the new technology of
oxo-biodegradable bags, emphasises that this does not release individuals
from their responsibility to the environment. Furthermore, as Habiba al
Marashi, chairperson of the EEG, states: “the government should come up
with regulations to limit the use of plastic bags while encouraging the
wider availability of reusable alternatives like jute bags, cloth shopping
bags, among others. The degradable plastic should only be one of the
alternatives.”
According to Mr Pryce, however, d2w is
“the solution to the plastic pollution problem... There is no viable
alternative to plastic.” But its real value may be in its use in
conjunction with a nationwide education policy about responsible disposal
and a commitment to recycling. It is an insurance policy, yes, but if we
really want to protect the environment, we should do as the EEG advises:
“We should reduce our waste by reducing our consumption and that is by
balancing our needs and wants. We should pick the items that we could
reuse and recycle from the things that we want to throw away. We do not
need high technology to do this, just our good old-fashioned common
sense.”
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