Blocks vs. slices — which form fits
Dry ice comes in a few common forms, and the right one depends on how long the cold has to last and how it is packed.
- Blocks — dense and slow to sublimate, blocks are the workhorse for longer transit times and larger loads. The lower surface-area-to-mass ratio means they hold cold longer.
- Slices — flat slabs cut from blocks, easy to layer above and below product in a box for even cooling. A good middle ground for shipping cartons.
- Pellets / nuggets — small pieces that pack tightly around irregular product, useful for shorter trips where fast, surrounding cooling matters more than duration.
How much dry ice do you need?
There is no single answer — the right quantity depends on the product, the insulation, the ambient temperature, and the transit time. A typical insulated container loses roughly 5 to 10 pounds of dry ice per day to sublimation, so a longer trip needs more. Rather than guess, tell us the shipment and we will size it for the journey.
Shipping dry ice is regulated
Because the CO₂ gas it releases can build pressure and displace oxygen, dry ice is a DOT/IATA Class 9 dangerous good (UN 1845) in transit. That means vented, properly rated packaging, the correct labeling and documentation, and a quantity calculated to last the trip — all of which our specialized-services team handles as part of a dry-ice shipment.
How to request dry ice from RS Group
Tell us what you are moving or storing, the quantity and form you think you need, the destination, and the transit time. A specialist will confirm the right dry ice and packaging and quote it. For shipments, this pairs with our regulated dry-ice freight service end to end.