Pressure vessel container (with foam inserts). Cardboard pieces (2: 1 for upright positioning of base of pressure vessel and 1 for placement on top of pressure vessel surrounded with dry ice). Absorbent paper (on bottom of pressure vessel) 5. Place vials to be returned inside of the pressure vessel, inserted upright in the holes of the foam inserts. Screw the lid shut on the pressure vessel. Multiple subjects’ /patients’ vaccines may be returned in 1 one pressure vessel. 6. Place a layer of dry ice on the bottom of the insulated liner that is within the outer cardboard shipping box. The pressure vessel container should then be placed above this layer of dry ice, with the base of the pressure vessel inserted into the cardboard support. Additional dry ice is then packed around the closed pressure vessel. The shipping container must be filled with at least 8 kg of dry ice (i.e., level with the top of the pressure vessel). A second cardboard insert should be placed above the dry ice, and the foam plug placed into the box. The box is then sealed with packing tape. 7. The following labels should be placed on the exterior of the outer cardboard shipping box: Dry ice (#9) with weight (8 kg). Shipping address/content label (where the package is being sent).