PPXX: Sustainable Stabiliser Systems for PVC – 30 Years of Ca-based Solutions

Abstract

NGO pressure and end of life disposal of PVC articles in the EU over 30 years ago, triggered intense discussion about the sustainable use of PVC and its additives. Stabiliser producers and downstream users of PVC stabiliser compounds base upon lead- and cadmium-based stabilisers have developed solutions ultimately leading to full substitution.

30 years later, Europe has completely eliminated lead use from primary PVC stabilisation additive use in all PVC including pipes and fittings where it was almost exclusively used. This replacement technology (referred to as calcium/zinc or calcium organic) is primarily based upon organic chemistry and metal carboxylates of calcium and zinc. This has been extended to almost all corners of the world over the past decade or so at a very high rate of acceptance, significantly, without enforced regulation or legislation being necessary. Who has selected which system and why for pipes and fittings? This presentation will present the current status.

The main driver today for choice of PVC stabiliser technology (aside of article performance against product standards) remains its total cost, taking into account all operational as well as material costs within the framework of regional chemical regulations allowing the use of chemical substances (e.g. REACh in EU).

Additionally, formulators have taken into account the sustainability of the whole system, including future substance regulation risk, end of life recyclability of the finished article as well as responsible and sustainable feedstock sourcing.

Moving forward, new product stewardship frameworks are being developed to deliver improvements to PVC additive sustainability, as promoted by VinylPlus with its ‘Additive Sustainability Footprint’, presenting new challenges and opportunities for formulators.

Changes in the reprotoxic classification for organotin stabilisers in Europe, in addition to scrutiny in other regions, is triggering downstream users to seek out similar solutions to substitute the use of tin stabilisers.

This presentation is going to shed light on these various aspects of the current use and future selection of the chemistry of PVC stabilisers for pipes and fittings.