PVC is all around you. At home, polyvinyl chloride makes everything from shower-curtains to food packaging and children's toys; at work, it makes vinyl flooring; on the road, car interiors; in medicine, syringes and bags for transfusions.

But PVC has achieved notoriety as well as ubiquity. Environmental groups like Greenpeace say that polymer threatens the environment and human health. The industry says such concerns are exaggerated or plain wrong.

Much is at stake. Current annual world-wide PVC production exceeds 20m tonnes. European production is more than 6m tonnes. In the UK, about 5,000 people are employed in making PVC and its feedstocks, and about 50,000 in processing and related jobs.

But the debate is about more than plastic. As with nuclear reprocessing, dumping oil rigs in the ocean or genetically modifying crops, the PVC industry tries to meet environmental campaigns with science. But the science is complex and incomplete. Each side is divided by differing attitudes to risk, doubts about how to manage that risk, and arguments about the right to pursue certain kinds of technological development. In other words, the debate is about politics.

That is an art at which Greenpeace excels. So far, companies like McDonald's, General Motors, Ford, IKEA, The Body Shop, Britain's Co-operative Bank, Lego and Nike have phased out PVC or pledged to do so. Local authorities in cities across northern Europe have also adopted PVC-free purchasing policies.

Legislation may be moving against PVC, too. Within the next few years, the European Commission may issue a directive imposing strong curbs on the industry. Clearly worried, PVC makers announced a voluntary code at the end of May that promises continuous environmental improvement in the manufacture of PVC, with the ultimate goal of "sustainability".

The European Commission released four studies in May emphasising the dangers of disposing of PVC. The amount of PVC waste in the EU is predicted to double to more than 6m tonnes per year by 2020, as long-lived products such as flooring, pipes and window frames, which account for 60 per cent of consumption, begin to enter the waste stream. The studies concluded that, unless something is done, PVC recycling levels will not exceed 20 per cent; and that both the alternative means of disposal, incineration and landfill, threaten the environment.

"The verdict is clear", says Greenpeace's Axel Singhofen. "Landfilling PVC is a ticking time bomb, incineration creates even more hazardous waste than before, and recycling is not a solution."

The industry was horrified. It complained the findings were flawed and mistaken.

The study, it said, overestimated the volumes of waste. The plastic was inert in landfill (the study assumed misleadingly high temperatures, it claimed); some 90 per cent of incineration was satisfactory. And there was huge scope for more recycling.

Who is right? First, using PVC is generally safe. The exceptions are few: some PVC toys contain phthalates, which are toxic and the subject of an EU directive; some Venetian blinds leach lead; and vinyl floors may cause childhood asthma, due to phthalate plasticers. PVC releases hydrochloric acid and dioxins when it burns, and these are very toxic.

But making PVC is dangerous and so is getting rid of it. Producing the basic feedstock of PVC, vinyl chloride monomer, creates by-products, including furans and dioxins. Lead, cadmium, organotins, phthalates and chlorinated paraffins keep PVC stable or make it supple. In landfills, these can leach out. If PVC is incinerated at low temperatures, it produces dioxins.

Manufacturers have made big strides in reducing risks. A study by Britain's National Centre for Business and Ecology found that PVC was only a minor source of environmental dioxins. Welcoming the Industry Charter drafted by the European Council of Vinyl Manufacturers, the NCBE concluded that there was "no evidence that in the context of society's activity as a whole, the level of harm caused by PVCs is such as to advocate their immediate withdrawal".

But accidents will happen. In the UK in March, emergency services went on full alert after hydrogen chloride spilled from a container at a European Vinyls Corporation (EVC) plant in Runcorn, Cheshire, a big vinyl producer formed in 1986 as a joint venture between ICI and Enichem, and spun off in 1994.

The NCBE report warned against complacency. The manufacturing creates hundreds of tonnes a year of waste vinyl chloride monomer and ethylene dichloride. Both are toxic.

For the PVC producers even this went too far. "Industry wasn't party to the initial group established by Greenpeace and the retailers," says Roger Mottram of EVC. "Certain things in the report [such as industry emission and control standards] were out of date and inaccurate."

A second chance came when an organisation called the Natural Step tried to build consensus. It brought together the Environment Agency for England and Wales, PVC makers and Greenpeace. The study asked what it would take for PVC to be sustainable long-term in line with environmental, social and economic goals everyone could agree.

Among the conclusions was that to be truly sustainable, the PVC industry would need to stop being an emitter of greenhouse gases. It would need to perfect a "closed-loop" system of waste management. And it must end the release of organochlorine compounds from the entire product life.

The industry is broadly happy with this. It thinks disposal is becoming easier, as recycling PVC into new products over and over again becomes easier - although consumers still have to be convinced that recycled products are no worse than new ones. In Germany, recycling is already proving profitable.

Now it was Greenpeace's turn to object - even though it had been involved. The Natural Step's work is based on science. It goes out of its way to encourage consensus. But Mark Strutt of Greenpeace says there is "no way the industry can meet" the Natural Step's challenges. If we were to ensure that the next generation of children are not exposed to the 300 or more industrial chemicals we all have in our bodies today, then there are a few materials that we are going to have to live without.

Instead, Greenpeace proposes alternative materials. Yet Mark Everard, of the Natural Step, says "history has seen a number of idiotic substitutions". The UK replaced organophosphate pesticides with synthetic pyrethroids, but that chemical has been found to be harmful.

"Greenpeace offers alternatives to PVC without validation of why these are better from a sustainability point of view", says Jason Leadbitter, of Hydro Polymers, the European producer, who also took part in the Natural Step's evaluation. "Some of the alternatives they suggest are much more energy intensive and also have deleterious environmental effects". After lobbying from Greenpeace and others, the Millennium Dome was made from PTFE-coated glass-fibre rather than PVC. Mr. Leadbitter says this cannot be recycled, costs more, and making it produces nearly seven times as much waste chlorine as PVC.

He believes a life-cycle analysis of PVC and its alternatives - to be published next month by Britain's Department of Environment, Transport and the Regions - will come out in PVC's favour.

Greenpeace reports that the alternatives to PVC do not require the use of halogenated substances (iodine, chlorine, bromine or fluorine), many of which are toxic.

At least two things are clear. First, the Natural Step demonstrates that production, use and ultimate disposal of PVC and its alternatives face huge and far-reaching challenges if they are to be sustainable.

The second is that all industrial processes are taking place in a political climate. When industrialists are challenged, they instinctively look to science for their support. But the science is usually too nuanced and intricate to come across in a shrill public relations war. Increasingly, therefore, science is not enough.

- Caspar Henderson
Financial Times - June 7, 2000