Increasing the Recycling of PVC Flooring Requires Phthalate Removal for Ensuring Consumers’ Safety: A Cross-Checked Substance Flow Analysis of Plasticizers for Switzerland

As our planet grapples
with the severe repercussions of plastic
pollution, mechanical recycling has been proposed as a potential remedy.
However, increasing mechanical recycling may have unintended negative
consequences. For example, recycling of PVC flooring containing hazardous
plasticizers that were used in the past may lead to continued exposure.
Here we propose measures to increase recycling while circumventing
adverse health impacts caused by legacy additives. For this, we conduct
a dynamic substance flow analysis for Switzerland and the time period
from 1950 to 2100, focusing on three plasticizers: di(2-ethylhexyl)
phthalate (DEHP), diisononyl phthalate (DiNP), and di(2-ethylhexyl)
terephthalate (DEHT). We quantify the uncertainty of results, check
their plausibility against measured concentrations in samples representative
for the Swiss market, and compare them with modeled substance flows
in Germany. Based on the cross-checked model, future average concentrations
of DEHP in PVC flooring on the Swiss market are expected to be above
the legal limit of 0.1 wt % for several decades if increased recycling
rates are implemented without additional measures. Phasing out the
potentially concerning DiNP, too, and preventing phthalates from entering
recycling would lower their average market concentrations to values
below 0.1 wt % and enable increasing recycling rates without compromising
product safety. Analogous measures could help achieve this goal across
other European countries and product groups.