Diisononyl Phthalate (DINP) — Frequently Asked Questions

Because both their performance and their toxicology differ. Larger, more branched molecules are held more firmly in the polymer, so they migrate and evaporate far more slowly, giving better permanence and lower emissions. Toxicologically the high molecular weight phthalates do not share the reproductive toxicity classification applied to DEHP, DBP and BBP.

No. It does not carry the reproductive toxicity classification applied to the low molecular weight phthalates in the EU. It is nonetheless restricted on a precautionary basis in toys and childcare articles that can be placed in the mouth, at a limit of 0.1 percent, so the application still determines whether it can be used.

Because it absorbed much of the demand displaced from DEHP as that material was withdrawn from general use. It offered comparable processing behaviour and better permanence without the classification, and it was available at scale. Non-phthalate alternatives such as DOTP and DINCH have since taken a growing share of that position.

It gels more slowly, because the larger branched molecule penetrates the polymer less readily, so processing temperatures or dwell times generally need increasing. Its viscosity is higher, which affects plastisol handling. Those are manageable adjustments but mean a substitution is not entirely drop-in.