These 50 lb. ice bags are made of extra strength heavy gauge Metallocene Low Density Polyethylene (LDPE) film that meets FDA/USDA specifications. This special poly film retains flexibility at low temperatures to reduce breakage. Tubular construction with a durable double bottom seal, make these bags the best ice bags on the market. Side gussets expand easily to accommodate fast loading. Can be heat sealed, tied, stapled or taped shut. See Ties for a complete list of bag closing options.