Low Density PolyEthylene (LDPE) is the most commonly used material for flexible packaging because it is tough, transparent and electrically stable. Low Density Polyethylene (LDPE) also has a low melting point, which is required for heat sealing applications. When low density polyethylene bags (LDPE) are made with virgin (no additives) polyethylene resin, they meet FDA standards for use with food products.