Dry ice is the solid form of carbon dioxide (CO2), produced by compressing and cooling CO2 gas until it liquefies and then allowing it to expand and solidify. It is much colder than water ice, with a surface temperature around −78.5 °C (−109.3 °F), and it sublimates directly from solid to gas without passing through a liquid phase under normal atmospheric conditions. Because of this property, dry ice is widely used for refrigeration during shipping, theatrical fog effects, laboratory cooling, and industrial cleaning. It provides colder temperatures than conventional ice and leaves no liquid residue, which is advantageous for transporting temperature-sensitive goods. Handling requires insulated gloves and adequate ventilation because prolonged skin contact can cause severe cold burns and accumulated CO2 gas can displace oxygen in confined spaces. Dry ice must be stored in insulated, vented containers; airtight containers can rupture from pressure buildup. Suppliers sell dry ice in blocks.

Dry ice (solid carbon dioxide) doesn’t melt; it sublimates directly from solid to gas. How long a piece lasts depends on mass, surface area, container quality, and ambient temperature. Small pellets or thin slabs have high surface area and sublimate quickly—minutes to a few hours at room temperature.

A 2–5kg block placed in an ordinary insulated cooler typically lasts 18–24 hours, while larger blocks and superior insulation can extend life to 2–3 days. Commercial-grade shipping coolers or thick polystyrene containers reduce sublimation, and wrapping dry ice in newspaper or towels slows gas escape. Warmer surroundings and frequent opening of the container accelerate sublimation; cold, sealed environments preserve it. Pressure and airflow also matter: more ventilation removes cold gas and increases sublimation.

For long-term storage, mechanical freezers cannot hold dry ice because it is colder than freezer components; instead, buy fresh supplies as needed. Always handle with gloves and store in well-ventilated areas to avoid CO2 buildup. Never store in airtight containers—the gas can build pressure and rupture the container. Plan quantities based on the expected duration plus a safety margin to account for faster-than-anticipated sublimation.

Refer below for guidance for recommended quantities.

If you are looking to store or transport food or other frozen goods then if the goods are pre-frozen the following is an approximate to the size and quantities of dry ice blocks you will require.

No. of DAYS Volume of Esky / Ice box.

25 Litre 40 Litre 60 Litre

1 day 1 x 3kg block 1 x 5kg block 1 x 5kg block

2 days 1 x 3kg block 1 x 5kg block 2 x5kg blocks

3 days 1 x 5kg block 2 x 3kg blocks 2 x 5kg blocks

4 days 1 x 5kg block 2 x 5kg blocks 3 x 5kg blocks

5 days 2 x 3kg blocks 2 x 5kg blocks 3 x 5kg blocks

6 days 2 x 3kg blocks 2 x 6kg blocks 3 x 6kg blocks

7 days 2 x 4kg blocks 3 x 5kg blocks 4 x 5kg blocks

Store dry ice in a well-ventilated area, never in airtight containers. Use an insulated cooler with the lid slightly ajar; wrap in newspaper to slow sublimation. Keep out of reach of children and pets, handle with thick gloves or tongs, and avoid prolonged indoor storage to prevent dangerous CO2 buildup.

It is not advisable to store dry ice in a normal household freezer as its extremely low temperature can cause damage to freezer components.

It is always best to purchase your dry ice as close to the time you are departing on your trip as possible. We generally require at least 24 hour’s notice and an approximate time you wish to collect so that we can make your Polar Dry Ice as fresh as possible.

Be sure to bring your esky/Ice box to collect your Polar Dry Ice. We also have Styrofoam and insulated Chill Boxes available if you require