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 that contains a category A substance cannot be transported on a passenger aircraft if it exceeds 50 mL or 50 gm.
If a category A specimen exceeds 50 mL or 50 gm, it must be transported on a cargo only aircraft, The black-on-orange label, shown on the right, must be affixed to the package. This is the only label that is in compliance for cargo-only packages.
A package containing category A substances that will be sent by cargo aircraft is limited to no more than 4L or 4 kg. This volume/weight does not include ice, dry ice, or liquid nitrogen, if any of these are used as refrigerants.
Category A substances cannot be mailed via the United States Postal Service (USPS) or sent via United Parcel Service (UPS).