The large amounts of dry ice needed to speed Covid-19 vaccine candidates to pandemic-weary populations will call for special attention from airlines and safety regulators.
Dry ice, the solid form of carbon dioxide, is a critical part of plans to transport the vaccine developed by Pfizer Inc. and BioNTech SE, which must be kept at ultracold temperatures. Pfizer expects to ship 50 million doses world-wide by the end of the year. The vaccine was the first to be authorized in the West, receiving clearance for emergency use in the U.K. last week. It is under review by the Food and Drug Administration in the U.S.
Widely used as a refrigerant, dry ice is classified as a dangerous good by the International Civil Aviation Organization and the U.S. Department of Transportation because it changes to gas form as it breaks down, a process called sublimation.
