Refrigerant Information and Courses from MediaLab, Inc.

The primary receptacle that contains a category A substance that will be sent at ambient temperature must be glass, plastic, or metal. A method must be employed to ensure that the receptacle is leakproof or siftproof (if the specimen is a dry particulate material). Acceptable methods include: heat sealing, using a skirted stopper or metal crimp seal. If screw caps are used, they must be secured by tape, paraffin sealing tape, manufactured locking closure, or similar methods. The completed package must be able to survive a drop test of 35 ft. A package containing category A substances that will be sent by cargo aircraft must be limited to no more than 4L or 4 kg. This excludes ice, dry ice, or liquid nitrogen, if any of these are used as refrigerants.If the package will be sent on a passenger aircraft, the quantity cannot exceed 50 mL or 50 gm. If a category A specimen exceeds 50 mL or 50 gm, it must be labeled as "Cargo aircraft only." Category A substances cannot be mailed via the United States Postal Service (USPS).

If dry ice is used as a refrigerant, it must be placed outside the secondary packaging. Interior supports must be provided to secure the secondary packaging in the original position after the dry ice has dissipated. The packaging must be designed and constructed to permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture the packaging. A "miscellaneous hazardous materials" label (class 9) must be affixed to the outer package along with a "dry ice" label that includes the UN designation "UN 1845." The net quantity (weight) of the dry ice must also be stated. If the package (category B or exempt substance) is sent through the mail, the amount of dry ice that can be used is limited to 5 pounds, unless advanced arrangements have been made.