What’s so wrong with PVC?
John Emsly
ECG bulletin July 2001
ECG bulletin July 2001
‘PVC and Persistent Organic Pollutants in the Environment’ was the general title for this year’s RSC Environmental Chemistry Group Distinguished Guest Lecture (DGL) and accompanying symposium. For his DGL, Dr John Emsley countered scientific myth with scientific facts for one of the many scare stories of our age - the adverse environmental and health effects associated with the manufacture and use of polyvinyl chloride (PVC).
PVC has become a particular target of the environmentalist movement Greenpeace. The reasons, according to their Mark Strutt, are as follows:
“Every PVC product plant releases hundreds of carcinogenic chemicals into the atmosphere every year. PVC is the source of dangerous amounts of hormone disrupting chemicals released into the environment each year. PVC does not biodegrade; it cannot effectively be recycled. It cannot be safely incinerated of land-filled. PVC can be replaced in virtually all its applications. Human health and the environment would be a lot better off without it.”
Strong words, and very much at variance with the opinions of those who make and use this polymer. They point out that PVC is stable and long-lasting (which brings important ecological benefits), it is durable and colourful (so makes ideal flooring); it is an excellent insulator and is non-flammable (so is idea for electric cables), it makes tough but flexible tubing which does not ‘kink’ (so is used in hospitals for drips and catheters), it can be recycled, and when it is manufactured and incinerated it produces little in the way of unwanted dioxins.
So why has this useful, safe and versatile polymer brought down upon itself the wrath of Greenpeace? The reason is that it is a product of the chlorine industry, and consequently it is seen as a product of the chemical they describe as the Devil’s element. Yet disasters have resulted from their opposition to chlorine, such as when they persuaded the Peruvian authorities to stop chlorinating water supplies, a policy which resulted in an outbreak of cholera, with a million cases and ten thousand deaths. Notwithstanding this, the campaign against chlorine goes on, and the war against PVC has been fought via press releases resulting in years of scare stories.
In the past ten years PVC has been implicated in the following scares (among others):
PVC has not been attacked per se, but through the additives it contains (antimony oxide fire retardants or phthalate plasticisers) or the dioxins that are formed during its manufacture or incineration. All these scares turned out to be false, but when they are exposed as such, the media tends to ignore the fact.
Nor does it help that many in the media are somewhat chemically challenged, so that they are incapable of understanding the negligible risk of PVC-derived dioxins. For example, Greenpeace’s booklet Dioxin Factories, the publication of which was linked to the formula feed scare of 1996, made the frightening claim that Europe’s chemical industry produced enough dioxin per year to give every living soul on Earth more than their maximum recommended annual dose.
This statement may be true, but only if the tolerable daily dose is taken to be 0.0062 picograms per kilogram of body weight per day as defined by the US Environmental Protection Agency which views dioxins are carcinogens. A simple calculation, based on an average body weight of 70 kg and a world population of 6.5 billions, reveals that only 1 gram of dioxin is needed to meet this claim. Greenpeace’s own ship Rainbow Warrior will have produced more dioxin than this in the past 20 years. (The burning of firewood in developing countries produces 3000 grams of dioxins every year.)
Every scare can similarly be show to derive from a deliberate distortion of data, and especially epidemiological data. For example, in 1998 it was said that men who had worked with PVC were prone to getting testicular cancer. This widely publicised assertion was based on a sample of 148 men with the disease, who had been treated at a medical centre in Sweden, and of whom 7 thought they had at some time worked with PVC. When the Swedish researchers were eventually challenged on the smallness of the sample they admitted that the link might in fact be ‘spurious’. However, by then their ‘findings’ had been accepted uncritically by New Scientist and from thence had passed to the wider media.
The credit card scare of March 1997, when Greenpeace and the Coop Bank launched a PVC-free card, was supported by large-scale press advertising which carried the message: ‘PVC is the mother of plastic pollutants and that chemicals released during its manufacture travel up the food chain and become concentrated in breast milk.’ The manufacturers of PVC, who complained to the Advertising Standards Authority, challenged this and finally this body delivered a judgement in December 1999 saying that the allegations were totally without foundation and that the adverts should not have been run. Few, if any, of the media carried that story.
And so it goes on, with the next likely scare being the use of PVC for blood bags and catheters, which by their very nature has to carry relatively high levels of plasticiser, minute traces of which are unavoidably leached into the fluid they carry. This scare story was first aired a year ago in the USA and made some headway, but it has yet to be tried in the UK.
Of course nothing produced by the chemical industry is entirely without risk – but the same can be said of most human endeavours - and it is very easy to write a dramatic press release linking a vulnerable groups to a terrifying threat. The groups generally chosen for a scare story are pregnant women, babies, young children, the sick and disabled, or wild animals; the threats are generally linked to cancer, heart disease, infertility, planetary damage, or to species on the verge of extinction. (PVC has suffered mainly from cancer and infertility threats).
The only way to counteract this kind of anti-PVC and anti-chemical propaganda is always to challenge wrong information, i.e. there must be zero tolerance of scientifically invalid statements in the media. The industry must provide independent sources of reliable scientific information, and recruit a panel of non-industry experts willing to speak out at a press conference immediately a new Greenpeace scare is launched, so that it can be nipped in the bud.
Greenpeace has a vital role to play in alerting the world to real environmental threats, such as over-fishing, heavy metal pollution, urban sprawl, and the destruction of natural habitats. Making an Aunt Sally of PVC is rather missing the point.
Dr JOHN EMSLEY, Science Writer in Residence, Dept of Chemistry, University of Cambridge.
April 2001
PVC has become a particular target of the environmentalist movement Greenpeace. The reasons, according to their Mark Strutt, are as follows:
“Every PVC product plant releases hundreds of carcinogenic chemicals into the atmosphere every year. PVC is the source of dangerous amounts of hormone disrupting chemicals released into the environment each year. PVC does not biodegrade; it cannot effectively be recycled. It cannot be safely incinerated of land-filled. PVC can be replaced in virtually all its applications. Human health and the environment would be a lot better off without it.”
Strong words, and very much at variance with the opinions of those who make and use this polymer. They point out that PVC is stable and long-lasting (which brings important ecological benefits), it is durable and colourful (so makes ideal flooring); it is an excellent insulator and is non-flammable (so is idea for electric cables), it makes tough but flexible tubing which does not ‘kink’ (so is used in hospitals for drips and catheters), it can be recycled, and when it is manufactured and incinerated it produces little in the way of unwanted dioxins.
So why has this useful, safe and versatile polymer brought down upon itself the wrath of Greenpeace? The reason is that it is a product of the chlorine industry, and consequently it is seen as a product of the chemical they describe as the Devil’s element. Yet disasters have resulted from their opposition to chlorine, such as when they persuaded the Peruvian authorities to stop chlorinating water supplies, a policy which resulted in an outbreak of cholera, with a million cases and ten thousand deaths. Notwithstanding this, the campaign against chlorine goes on, and the war against PVC has been fought via press releases resulting in years of scare stories.
In the past ten years PVC has been implicated in the following scares (among others):
- PVC mattresses cause cot death.
- Burning PVC releases deadly dioxins.
- Phthalates from PVC contaminate formula feeds for babies.
- PVC credit cards are dangerous.
- Babies’ toys made from PVC release ‘gender-bending’ chemicals.
- Men who work with PVC are prone to testicular cancer.
PVC has not been attacked per se, but through the additives it contains (antimony oxide fire retardants or phthalate plasticisers) or the dioxins that are formed during its manufacture or incineration. All these scares turned out to be false, but when they are exposed as such, the media tends to ignore the fact.
Nor does it help that many in the media are somewhat chemically challenged, so that they are incapable of understanding the negligible risk of PVC-derived dioxins. For example, Greenpeace’s booklet Dioxin Factories, the publication of which was linked to the formula feed scare of 1996, made the frightening claim that Europe’s chemical industry produced enough dioxin per year to give every living soul on Earth more than their maximum recommended annual dose.
This statement may be true, but only if the tolerable daily dose is taken to be 0.0062 picograms per kilogram of body weight per day as defined by the US Environmental Protection Agency which views dioxins are carcinogens. A simple calculation, based on an average body weight of 70 kg and a world population of 6.5 billions, reveals that only 1 gram of dioxin is needed to meet this claim. Greenpeace’s own ship Rainbow Warrior will have produced more dioxin than this in the past 20 years. (The burning of firewood in developing countries produces 3000 grams of dioxins every year.)
Every scare can similarly be show to derive from a deliberate distortion of data, and especially epidemiological data. For example, in 1998 it was said that men who had worked with PVC were prone to getting testicular cancer. This widely publicised assertion was based on a sample of 148 men with the disease, who had been treated at a medical centre in Sweden, and of whom 7 thought they had at some time worked with PVC. When the Swedish researchers were eventually challenged on the smallness of the sample they admitted that the link might in fact be ‘spurious’. However, by then their ‘findings’ had been accepted uncritically by New Scientist and from thence had passed to the wider media.
The credit card scare of March 1997, when Greenpeace and the Coop Bank launched a PVC-free card, was supported by large-scale press advertising which carried the message: ‘PVC is the mother of plastic pollutants and that chemicals released during its manufacture travel up the food chain and become concentrated in breast milk.’ The manufacturers of PVC, who complained to the Advertising Standards Authority, challenged this and finally this body delivered a judgement in December 1999 saying that the allegations were totally without foundation and that the adverts should not have been run. Few, if any, of the media carried that story.
And so it goes on, with the next likely scare being the use of PVC for blood bags and catheters, which by their very nature has to carry relatively high levels of plasticiser, minute traces of which are unavoidably leached into the fluid they carry. This scare story was first aired a year ago in the USA and made some headway, but it has yet to be tried in the UK.
Of course nothing produced by the chemical industry is entirely without risk – but the same can be said of most human endeavours - and it is very easy to write a dramatic press release linking a vulnerable groups to a terrifying threat. The groups generally chosen for a scare story are pregnant women, babies, young children, the sick and disabled, or wild animals; the threats are generally linked to cancer, heart disease, infertility, planetary damage, or to species on the verge of extinction. (PVC has suffered mainly from cancer and infertility threats).
The only way to counteract this kind of anti-PVC and anti-chemical propaganda is always to challenge wrong information, i.e. there must be zero tolerance of scientifically invalid statements in the media. The industry must provide independent sources of reliable scientific information, and recruit a panel of non-industry experts willing to speak out at a press conference immediately a new Greenpeace scare is launched, so that it can be nipped in the bud.
Greenpeace has a vital role to play in alerting the world to real environmental threats, such as over-fishing, heavy metal pollution, urban sprawl, and the destruction of natural habitats. Making an Aunt Sally of PVC is rather missing the point.
Dr JOHN EMSLEY, Science Writer in Residence, Dept of Chemistry, University of Cambridge.
April 2001
