The shelf life of dry ice is affected by the quantity of dry ice, its packing, and storage. Below are some examples of evaporation times:
- 1 kg at room temperature on a table, 6-8 h
- 10 kg at room temperature in a Styrofoam box, 1-2 days
- 20 kg at room temperature in a Styrofoam box, 3-4 days
- 20 kg in a deep-freezing room in a Styrofoam box, 4-5 days
The best container for dry ice is a Styrofoam box or a cooler that is stored as cool temperature as possible; for example outdoors during the winter and in a cool storage during the summer. Remember to keep the container lid shut.
A small quantity of dry ice (maximum of 20 kg) can be stored in a Styrofoam container in a deep-freezing room or other such facility. Dry ice should not be stored in a home freezer or in the ice box of a refrigerator, since dry ice is much colder than what the thermostats of such devices are designed to handle.
The larger the quantity of tightly packed dry ice, the lower the evaporation percentage. Evaporation can be slowed down by packing the ice as tightly as possible and by filling any empty space with Styrofoam and newspapers. In other words, dry ice should be packed in a way that leaves as little air space as possible around the ice.
One kilogram of dry ice generates about 530 litres of carbon dioxide gas. Therefore, leave enough open seams in the box to prevent excessive pressure build-up.
