The only hold time that counts is the one your laboratory has measured. A dry shipper stays cold until the liquid nitrogen absorbed in its porous liner has evaporated, and three things shorten that.
Charge quality
A shipper filled, left to saturate properly and then drained of free liquid will outlast one charged in a hurry before a courier arrives.
Orientation
Laid on its side in transit, a shipper loses hold time it never advertised losing.
Ambient temperature
A hot van on a summer motorway is not a laboratory corridor.
What validation actually requires
ESHRE’s 2026 laboratory recommendations set the standard plainly: dry shippers should be validated for maintenance below minus 150°C for the maximum anticipated transport duration. That means logging your own shipper, charged your own way, under conditions that resemble the journey, rather than quoting a datasheet at an inspector.
Cryolab’s CryoStork® dry shippers run from the 2 litre V2 to the 10 litre V10, and a cryogenic data logger with a PT1000 probe records the trace for each journey. Manufacturer hold time figures come with the product documentation, since they depend on the test conditions used.
Match the shipper size to your longest realistic journey, not your average one, on the CryoStork® range page.
