Plastic wastes that litter cities, parks, beaches and countryside look
depressingly the same everywhere on earth. They have come to symbolise the
mass throwaway culture: cheap, trashy, transient yet stubbornly non-degradable
and inassimilable. These by-products of the oil industry are icons of the
industrial economy built on the over-exploitation of oil and other fossil
fuels that’s turning the planet literally into a terminal wasteland. Dealing
with plastic wastes has taken on significance not far short of ultimate redemption.
The world consumes 100 million
tonnes of plastic materials - 36.8 million tonnes in Europe,
5 million tonnes in the UK - and growing at 3 to 4 percent each year [1,
2]. The largest single sector, 37.3 percent, is in packaging. There are about
50 different groups of plastics with hundreds of different varieties.
The amount of plastic wastes
generated annually in the UK was estimated at 3 million tonnes
in 2001. Although all types of plastics could be recycled, only 7 percent
actually were. The rest were buried in landfills (80 percent) or incinerated
(8 percent). Most plastics are non-biodegradable, which means they take a
long time to break down naturally.
Significant amounts of fossil
fuels are required to make plastics, both as a raw material and as energy
for manufacture. About 4 percent of the world’s annual oil production is used
for as raw material and another 3-4 percent for manufacture.
Plastics manufacture requires
a lot of water, produces waste and greenhouse gas emissions, and involves
using harmful chemicals, especially with polyvinylchloride (PVC), the second
most common kind of plastics in the world, where further toxic chemicals are
generated during manufacture [3,4]. Burying plastic wastes in landfills or
burning them in incinerators create still more hazards for health and the
environment (see Box).
The best way to cut down
on plastic wastes is to reduce use, to eliminate unnecessary packaging, and
to reuse items such as plastic bags, toys, cosmetic bottles, etc. The next
best way is to recycle.
Poison plastic PVC
PVC, polyvinyl chloride,
is the second most commonly used plastic in the world, and causes the most
problems for health and the environment. It is the largest source of dioxin
when burnt in incinerators and in accidental fires in buildings. Dioxin
is also created during the manufacture process, and toxic chemical additives
are incorporated in PVC products.
The largest use of PVC is in building materials: cables, window frames, floors,
walls, panelling, water and wastewater pipes, vinyl flooring, wallpaper, window
blinds and shower curtains. It is in consumer articles such as credit cards,
records, toys, office furniture, binders, folders, and pens, in the car industry
as underseal, in hospitals for medical disposables, as imitation leather, and
The production of PVC involves transporting dangerous explosive materials such
as vinyl chloride monomer (a carcinogen), and creating toxic wastes, notably
ethylene dichloride tars. Tar wastes contain huge quantities of dioxins, which
when incinerated or dumped, spread dioxins into the environment. Numerous additives
are incorporated into the product, including softeners to make it flexible,
heavy metals to stabilise colours, and fungicides. Dioxins are generated during
manufacture, which end up in the process wastes, and sometimes in the product
itself. Plasticisers are not bound to the plastic and can leach out over time;
plasticisers in vinyl floors evaporate into the room. The most common plasticiser,
the phthalate DEHP (Di(2-ethylhexyl)phthalate), is a suspected carcinogen, and
over 90 percent are used solely to make soft PVC plastic, including baby toys
and teethers. Since 1999, the European Union has prohibited phthalates in toys
intended to be place in the mouth of children under three years of age .
The disposal of PVC
creates more problems. If burned in open fires or incinerators, it releases
an acidic gas along with dioxin. If landfilled, it releases additives that
contaminate the groundwater, and landfill fires involving PVC are a further
source of dioxin.
TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), the most lethal member of the dioxin
family, is a known human carcinogen and hormone disrupter, and is recognized
as the most toxic synthetic compound ever produced. All humans and animals now
carry burdens of TCDD and other dioxins in their bodies.
As much as 3.2 million
tonnes of PVC are discarded as waste in the US every year, 70 percent consisting
of packaging and bottles. PVC is difficult to recycle and contaminate other
plastics. Concerned environmental groups want it to be phased out altogether.
Recycling plastic wastes saves energy and carbon emissions
Producing carrier bags from recycled rather than virgin polythene reduces
energy consumption by two-thirds, produces only a third of the sulphur dioxide
and half of the nitrous oxide; it reduces water use by nearly 90 percent,
and carbon dioxide emission two and a half times. For every tonne of recycled
polythene produced, 1.8 tonnes of oil are saved .
Recycling is done mechanically or chemically. In mechanical recycling, the
waste plastics are sorted, then melted, shredding or turned into granules and
moulded into new shapes.
In chemical recycling, the plastic polymers are broken down into their constituent
monomers by heat treatment (thermal depolymerization), which can then be used
again in refineries or petrochemical and chemical production. The UK does not
operate any full-scale chemical recycling plants, as according to UK’s Department
of Trade and Industry , capital investment requirements are much higher than
for mechanical recycling plants (but see “Waste plastics into oil”, this series).
Despite the wide range of recycled plastics applications, the actual tonnage
of waste plastic returned to the material cycle is relatively small. Currently,
recycled plastics are rarely used in food packaging – the biggest single market
for plastics – because of concerns about food safety. Another constraint on
the use of recycled plastics is that, to be economically viable, plastic processors
require large quantities of recycled plastics manufactured to tightly controlled
specification at a competitive price compared to the virgin polymer.
Legislating for recycling
The 1994 European Union Directive on Packaging and Packaging
Waste 94/62/EC (the Packaging Directive) aimed to establish producer responsibility
for packaging waste. The directive was implemented in the UK through the Producer
Responsibility Obligations (Packaging Waste) Regulations 1997 and the Packaging
(Essential Requirements) Regulations 1998. The former sets targets for the
recovery and recycling of packaging wastes, including plastics packaging waste.
The UK government published the national packaging recycling and recovery
targets for 2004 and beyond. These required 21.5 percent of plastics waste
to be recycled by 2004, rising to 23.5 percent by 2008.
The Waste and Resources Action Programme (WRAP) was established in the UK in
2001 to promote sustainable waste management. WRAP’s particular focus is creating
stable and efficient markets for recycled materials and products.
WRAP runs a specific programme on plastic wastes. It set a target to increase
mixed plastic reprocessing by 20 000 tonnes by 2003/2004, which has yet to be
met . Its target for 2004/2006 is to work with the wider plastics industry
to increase the acceptance of recycled plastic throughout the supply chain,
to deliver an additional 20 000 tonnes of domestic plastic bottle recycling
capacity, and to ensure an additional 11 000 tonnes of non-bottle plastics are
UK’s Department for the Environment, Food and Rural Affairs has put out an
action plan for a nationwide farm plastics collection and recovery scheme last
year, and Waste Management Regulations will apply to agricultural waste in 2005
. Farms produce more than 80 000 tonnes of waste plastic a year, such as
fertiliser bags, animal feed bags and agrochemical containers, silage films,
crop covers and tunnel films. Burning waste plastics ether in the open or in
a drum incinerator – the current disposal option for most farmers - may no longer
be available in future.
Outsourcing plastic wastes
But what really happens to the plastic packaging and bottles that the
British consumer diligently places in the recycling bin for collection by
the local authorities, and, more so, those that supermarkets, the biggest
users, are supposed to be responsible for recycling?
It turns out that more than
a third of the waste paper and plastic collected by British local authorities,
supermarkets and businesses for recycling have been sent 8 000 miles to China
. Exports to China are running at 200 000 tonnes of plastics rubbish a
year. UK’s supermarket chains, some of the largest generators of plastic packaging
waste in Britain, are getting their recycling done in China. Environmental
groups and Members of Parliament were shocked at the scale of the trade. No
studies have been done on the environmental costs of shipping wastes to China.