Why is DOTP replacing DOP as the mainstream plasticizer in PVC products?

Why is DOTP replacing DOP as the mainstream plasticizer in PVC products?
DOTP has overtaken DOP as the largest-capacity plasticizer for the first time in six decades, driven by both regulation and performance. Structurally it is DOP's twin, but the para-position carboxyl groups deliver higher volume resistivity (around 10^14 versus 10^12 ohm-cm), lower volatility, and better heat, migration, and extraction resistance. It passes EU RoHS and REACH and is FDA-permitted for food contact, while DOP faces restrictions. The trade-off is price: DOTP runs roughly 700 yuan/ton above DOP, and plasticizing efficiency is about 10% lower, with slightly weaker low-temperature flexibility. For wire, cable, and durable PVC, that premium is usually justified.