PVDC (Polyvinylidene Chloride) (C₂H₂Cl₂)_n is a highly effective barrier coating polymer that is produced by the polymerisation of a vinylidene chloride monomer with other monomers such as acrylic esters and unsaturated carboxyl groups. It is the chemistry, density and symmetry of the molecules in PVDC that give the material its excellent barrier properties against fat, vapor and gases. This molecular structure results from the combination of salt (50-70%) and oil (30-50%).

PVDC’s outstanding barrier properties make it ideal for use in food packaging, and it is particularly effective for products with a high fat content and strong flavors and aromas. It is often used in the packaging of confectionary products, dehydrated foods, dairy products, sausages, patés, meat, smoked fish, and dried products such as herbs, spices, tea and coffee.