This standard was proposed by the Hebei Provincial Bureau of Standards and Metrology. This standard was drafted by the Hebei Provincial State-owned Hangu Farm Plastics Factory. This standard refers to the standards of French PREPAC company and Finnish ELECSTER company. This standard specifies the specifications, technical requirements, test methods, packaging markings, transportation and storage of packaging composite films for freshness preservation. This standard is applicable to packaging composite films for preservation of milk, beverages, etc., which are made of high-pressure polyethylene as the main raw material and made by co-extrusion blow molding with a black inner layer and a white outer layer. It is also applicable to printed composite films.