1 May 2014 – Vinyl is the common name used for polyvinyl chloride, or PVC – plastics which are almost ubiquitous in their use across the built environment, in personal items, food and beverage packaging, wall coverings, carpet backings, water-proofing membranes, pipework, cable sheathing, children’s toys, plastic cling film, shoes… the list goes on.
The sticking point for environmental advocates with PVC is the chlorine that forms a key part of the polymer. The use of this highly reactive element can create dioxins during both the manufacture and disposal of PVC. Dioxins are highly carcinogenic and persistent organic pollutants (POP) that concentrate – bioaccumulate – both in body tissues and in the food chain and are recognised as one of the groups of chemicals of global concern are covered by the Stockholm Convention.
Under the convention, Australia has pledged to prioritise elimination of processes that produce dioxins. The important distinction here is that Australia didn’t pledge to manage emissions better – we didn’t pledge to burn the waste more efficiently, and we didn’t pledge to recycle them more often.
The signatories of the convention pledged to eliminate manufacturing processes which produce dioxin, which PVC production inevitably does, it’s simply how the chemistry works.
According to the GBCA’s media statement on the revised guidelines stated: “We’ve listened to feedback from manufacturers and industry, we’ve conducted a literature review and we’ve consulted independent experts. As a result, we have now revised the Best Practice Guidelines for PVC in the Built Environment.
“The revised guidelines address the differences between the two types of polyvinyl chloride: Emulsion PVC (E-PVC) and Suspension PVC (S-PVC). The revisions ensure a realistic best practice benchmark is prescribed to E-PVC and that the PVC credit continues to promote best practice. The benchmark for S-PVC remains unchanged; the change to the E-PVC component will only influence PVC-backed carpet.”
What it means
The new best practice guidelines for the use of PVC are intended for use by manufacturers of PVC resin, PVC conduit, pipes and fittings, cable and wire insulation and flooring, and aim to assist them to “substantially minimise” the health and environmental risks arising from the lifecycles of the products.
This includes sourcing the base materials from closed-lid production manufacturing plants; provisions for waste management, which includes the option of disposal to landfill where high temperature, emission-controlled incineration is not available; treatment of effluents; and “effective emission reduction measures… to ensure that [vinyl chloride monomer] and/or [ethylene dichloride] emissions and possibly other contaminants, are close to, or below, negligible risk levels.”
There is still an issue with the toxins
The difficulty remains, however, that even at negligible levels dioxins remain highly toxic. The dioxins emitted by PVC manufacture and during the disposal phase are pollutants that do not biodegrade. They accumulate in the environment and enter the food chain through air, water and soil, where they bio-accumulate (build up in body tissues).
Dr Mariann Lloyd-Smith, senior advisor for the International POPs Elimination Network and the National Toxics Network (Australia), said that while the Vinyl Council may claim it is using a better form of phthalates, in reality manufacturers are still producing dioxins in both the manufacture and the waste phases of PVC.
She explained that while manufacturers have shifted away from the use of DEHP – “the real shocker” – to phthalates such as DINP and DIDP, which have a higher molecular weight and therefore do not bioaccumulate to the same extent, there are still concerns. When NTN looked into these compounds, it found they still had endocrine impacts, including effects on prenatal development, such as lower testosterone levels, and that both these compounds have also led to liver cancer in rats and mice during laboratory trials.
She also pointed out that in Europe the use of PVC in children’s toys is banned due to the established health risks.
“These [other] phthalates might not be as nasty, but they are still nasty,” Dr Lloyd-Smith said.
“The other problem with PVC is you still have the vinyl monomer [in the material], which is a carcinogen, and during the manufacture process it is still creating air[borne] emissions of a very toxic chemical.
“I can’t see there is a softer, more loving and warmer form of PVC.
“We are supposed to be eliminating dioxins to the best of our ability, so we should not be using anything that makes dioxins.”
Most of our PVC comes from offshore
Dr Lloyd-Smith pointed out that in Australia we use a “phenomenal” amount of PVC products, the majority of which are manufactured offshore. This means it is difficult for Australia’s Vinyl Council to control what form of PVC is in products, and it also makes it difficult for end users to have certainty, as there is to her knowledge no Australian Standards requiring the type of PVC to be specified when importing many PVC products.