Abbreviation for polyvinylidene chloride, a carbon-based plastic. PVDC has been used in the packaging industry for several decades to protect numerous food and pharmaceutical products from spoilage. Positive properties are its food safety and low permeability to oxygen. It is considered to be the best closure material with absolute tightness and chemical inertness (reaction inability). In the wine industry, PVDC films are also used for capsules (cover over natural corks), as well as for alternative wine bottle closures such as screw caps and crown caps. See also under similar materials such as polyethylene (PE) and PVC, and under closures.