First and most important a good insulated container is needed. An inexpensive styrofoam cooler from the grocery store will rarely work. It breaks easily and usually is not the right shape for shipping. A thick poly styrene box like Omaha Steaks uses, a high quality urethane box or the newest box from Control Temp Packaging will reduce the amount of dry ice needed and allow extended shipping times.

Next is the shipping temperature. Use Dry Ice for shipping FROZEN goods as Dry Ice will freeze everything in the shipping box. Use "gel packs" or "blue ice" for goods to be REFRIGERATED. A combination of dry ice and gel packs will extend the shipping time by several days if the shipped items can be frozen for a short time or thawed for a short time.

For Dry Ice plan on using 5 to 10 pounds for each 24-hour period depending upon the quality of the insulated shipping container. This will keep everything frozen in a container up to 15 quarts. For larger containers and greater shipping times multiply dry ice quantities by this rate. The best shipping container is a two-inch thick urethane insulated box tested to lose only 5 pounds for a 10-quart storage volume every 24-hours. Newer materials developed for Control Temp Packaging in Norcross, GA have tested nearly the same as urethane. Less thick or efficient insulation will need more Dry Ice because it will sublime faster. 

For gel packs, as a generality use one pound per cubic foot per day. (Most gel packs come in 1/2 pound size but newer ones are up to 2 pounds.) This will be last for up to three days. For a longer time Dry Ice has to be combined to extend the gel packs with the possibility of freezing the goods briefly in the beginning.

When packing items in the container fill the empty space with wadded newspaper or Styrofoam peanuts as any "dead-air-space" will cause the Dry Ice to sublimate faster.

Dry Ice sublimation (changing from a solid to a gas) will vary depending on the outside temperature, air pressure (on an airplane with lower air pressure it will sublimate faster) and efficiency of the insulation. The more Dry Ice you have stored in the container, the longer it will last. Dry Ice, at -109.3°F or -78.5°C, will freeze and keep frozen everything in the container until it is completely sublimated. These frozen items will still take some extra time to thaw because they will have been so cold.

The table below adds extra Dry Ice for heavier items because some of the Dry Ice will be used up lowering the temperature of the product to be shipped to the temperature of Dry Ice: -109.3°F.