PVC is a rigid plastic and is used in this form in products such as doors and window frames. These have stabilisers added to ensure a longer product life. If PVC needs to be more flexible, in packaging and medical devices, it has plasticisers added to it.
There is some controversy as to the dangers of these additives.
Click for details on phthalate additives in
medical devices.
Metallic stabilisers
PVC manufacturers add lead, cadmium, tin, zinc and barium as stabilisers
to PVC. These heavy metals have been proven in the past to cause severe
pollution and environmental damage. This is just one of the reasons
why Greenpeace have called for a ban on the use of PVC.
The compounds added to PVC are stable metal salts and there is no evidence
of harmful medical effects despite these stabilisers being used for
many years. One report concluded it was just as safe to eat off a lead-stabilised
PVC pipe as it was to eat from a ceramic plate.
Do additives make PVC an unacceptable risk? Or do they allow PVC to be used in a wide range of products and outweigh the risk?
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Plasticisers
Additives, such as phthalates, make PVC flexible and are found in blood
bags, children's soft toys and other products. Laboratory studies in
animals show that they are linked to cancer and kidney damage. Testing
by several governments conclude soft PVC should not be used to make
toys that children may chew.
The studies in rats do not have any relevance to the effects of phthalates
in humans. Phthalates are biodegradeable and have low toxicity.
Plasticised PVC has been used for more than 40 years and has not been
proved to cause any ill-health or environmental damage. So much research
means that there is probably more known about phthalates than almost
any other chemical.