Diisononyl adipate is widely used as a plasticizer in the production of flexible polyvinyl chloride (PVC) products. It enhances the flexibility, durability, and workability of PVC, making it suitable for applications such as cables, wires, flooring, and automotive parts. Its low volatility and resistance to extraction by water and oils make it ideal for use in environments requiring long-term stability. Additionally, it is employed in synthetic rubbers and coatings to improve elasticity and performance. Its compatibility with various polymers and non-toxic nature also make it a preferred choice in consumer goods like toys and food packaging materials.