UN Markings

This is in response to your letter dated May 23, 1995, requesting clarification on the proper location of UN markings on combination packages.

Sections 178.3 and 178.503 of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) require that UN markings be placed on the outside of the package. Combination packages are tested as a single unit or a package that includes the inner receptacles or containers, cushioning materials, and outside package. The UN certification markings should be placed on the outside package in an unobstructed area. The markings must be stamped, embossed, burned, printed or otherwise marked on the package to provide adequate accessibility, permanency, contrast, and legibility in order to be readily visible and understood. Packages with a gross mass of more than 30 kg (66 pounds) must have the marking or a duplicate thereof on the top or on a side.