Milk Product Packaging in Japan
In Japan, the Ministry of Health, Labour, and Welfare (Ministry of Health) has the authority to establish specifications for packaging materials under the 1947 Food Sanitation Law.Such specifications exist for a range of different packaging materials intended to hold food in general, including synthetic resins, metal cans, glass, and rubber articles. Specifications also exist for packaging materials intended to hold specific food products such as edible ices and nonalcoholic beverages, and packaging for food sold in vending machines. This article outlines the Japanese Ministry of Health specifications that apply to packaging materials for milk and milk products.
The Ministry of Health specifications for milk packaging are divided into three categories and depend on the type of milk or milk product packaged. The three categories are unfermented milk, fermented milk,1 and prepared milk powder. Unfermented milk includes cow's milk, special cow's milk, pasteurized goat's milk, partly-skimmed milk, skimmed milk, processed milk, and cream. Fermented milk includes fermented milk, fermented milk drink, and other milk drinks.
Unfermented milk may be packaged only in glass bottles, polyethylene or ethylene/1-alkene copolymer packages, polyethylene coated paper, ethylene/1-alkene copolymer coated paper, or combinations of these types of packaging materials.2 The polyethylene or ethylene/1-alkene resins used to package unfermented milk must not contain any additives other than calcium stearate (maximum use level of 0.25%), titanium dioxide, and glycerin fatty acid ester (maximum use level of 0.03%). (This is a somewhat peculiar limitation as we understand that additives, such as antioxidants and stabilizers, are commonly used in polyethylene. Such additives would not be permitted under this specification for milk packaging.) The end tests requirements for polyethylene milk packaging are somewhat more restrictive than those required by the Japanese Ministry of Health for polyethylene used to package foods generally. In addition, the milk packaging specification requires that the n-hexane extractives must not exceed 2.6%, the xylene-soluble fraction must not exceed 11.3%,3 the level of arsenic must not exceed 2 ppm (as As2O3), and the heavy metal (lead) content must not exceed 20 ppm (as Pb). The specifications also include testing to determine the strength of the package, including a burst strength test, sealing strength test, and a pinhole test.
In addition to the packaging that is permitted for unfermented milk, fermented milk, fermented milk drink, and milk drinks may also be packaged in polystyrene and polymer coated metal. Other synthetic resins may be used to produce packaging for fermented milk; however only polyethylene, ethylene/1-alkene copolymers, and polystyrene may be used in contact with fermented milk or milk drinks. The specifications for polystyrene used to package milk are also somewhat different than the Japanese Ministry of Health specifications for polystyrene used to package food, generally. There are tighter standards for volatile substances, and the limits on extractable residue are somewhat lower. Packaging for fermented milk must also be tested for package integrity by conducting penetrating strength testing, sealing strength testing, and pinhole testing.
As noted above, metal and polymer coated metal containers may be used to package fermented milk. The testing specified for these materials is similar to the testing required for metal cans used to package other foods; however, the standards are somewhat tighter. For example, the limit on arsenic in metal used to package food, generally, is 0.2 ppm, while the limit of metal used to package milk is 0.1 ppm.
Powdered milk may be packaged in metal cans and synthetic resin packaging. The specifications note, however, that only certain synthetic resins may be used in contact with the powdered milk. These resins include polyethylene, ethylene/1-alkene copolymers, polystyrene, and polyethylene terephthalate.
In summary, when providing a compliance statement regarding the compliance of a packaging material under Japanese law, one must bear in mind that milk packaging is regulated differently. A polymer manufacturer may want to limit its assurance to non-milk packaging or understand what particular applications are contemplated by its customer before providing a blanket assurance statement regarding a package's compliance with Japanese law.
1 Fermented milk drinks, which are somewhat similar to a yogurt based drink, are commonly consumed in Japan as a health drink. Fermented milk drinks are made by fermenting skim milk powder and sugar with the beneficial bacteria. Such drinks are sold in vending machines and supermarkets.
3 These limitations on n-hexane extractives and xylene soluble fraction are identical to those required for polyethylene under the U.S. Food and Drug Administration's food additive regulation, 21 C.F.R. § 177.1520(c), Item 2.2.