Legacy additives define substances legitimately used in the past but now restricted or subject to authorisation. Legacy additives incorporated in PVC-based products in current use and reaching end-of-life also present a clear challenge when striving for the sustainable use of additives (as well as addressing other PVC sustainability challenges).
This exposes potential conflicts, for example, between restricting hazardous substances yet ensuring that these constituents in end-of-life PVC products do not inhibit their reuse in recycled products. In most cases, the recycling of PVC (manufacturing new PVC articles from those that have reached the end of their useful life) represents the most efficient way to reduce pressure on raw material and energy inputs.
Doing so may also comply with TNS System Conditions where legacy substances contained in used PVC article (including for example some heavy metals that are no longer permitted in the manufacture of virgin PVC) remain embedded into the PVC matrix of new articles, and hence do not contribute to systematic accumulation in nature.
To minimise such dilemmas in the future, robust selection criteria are required to help us select the best additive raw materials based on comprehensive information provided by the suppliers, whilst also recognising that stepwise progress will be necessary leading strategically towards the longer-term goal of achieving full sustainability.