DiNP

Diisononyl phthalate (DINP) is a high-molecular-weight plasticizer used to impart flexibility to polyvinyl chloride (PVC) and other polymers. It is a phthalate ester composed of phthalic anhydride and isononyl alcohol, typically sold as a mixture of isomeric diisononyl esters. DINP is valued for its relatively low volatility, good compatibility with PVC, and durable performance in end products.

DINP is widely used in a range of PVC formulations, including flexible films, coatings, cables and wires, flooring, and automotive interiors. It has also been employed in other consumer goods where flexible plastics are needed. Because it is a large molecule with limited migration, DINP is often chosen as a lower-volatility alternative to some lighter plasticizers.

Regulatory and safety status varies by jurisdiction. In the European Union, DINP and related high-molecular-weight phthalates are subject to restrictions in toys and childcare articles, with limits often set at 0.1% by weight of the article. In the United States, DINP is among the phthalates restricted by the Consumer Product Safety Improvement Act for toys and certain child care articles. Manufacturers frequently substitute DINP or use alternative plasticizers in products intended for children.

Health and environmental considerations are governed by ongoing toxicological assessments. DINP has low acute toxicity in humans, but animal studies have indicated potential reproductive and developmental effects at high doses, leading to stricter regulation and a preference for alternatives in sensitive uses. Environmentally, DINP is persistent to some extent and can migrate from PVC-containing products into dust and the environment, though its ecological impact is generally managed through regulatory controls and formulation choices.

See also: phthalates, plasticizers, PVC.