Dry ice logistics & cold chain

Dry ice (solid CO₂, sublimation temperature −78.5 °C) is the standard coolant for temperature-sensitive supply chains from −70 °C deep-freeze (mRNA vaccines, specialty chemicals) down to −20 °C Surlyn and dry-ice blasting. The challenge is not the temperature itself but sublimation loss: a poorly insulated container loses 8–15 % of dry ice per day, a well-insulated one less than 4 %.

The key parameter is therefore insulation thermal conductivity. 80 mm high-density PUR foam (λ = 0.02372 W/mK) yields about 21 W/m² heat transfer at 20 °C ambient and −78.5 °C interior — equivalent to about 3 kg dry-ice loss per day per m² external surface. For a 600-litre container that means a 5–7 day hold time with a 50 kg dry-ice charge.

The seamless rotomoulded shell is decisive here. Where welded containers typically show thermal bridges with 5–8 W/m² extra loss at seams, our process has none. That increases effective cooling time by 15–25 % over welded products of identical wall thickness.

Dry ice is UN 1845 dangerous goods (class 9). Road (ADR), sea (IMDG) and air (IATA DGR) transport all have specific labelling, packaging and documentation duties. Our containers come with pressure-release vents that reliably relieve overpressure above 0.7 bar — mandatory because sublimed CO₂ can generate up to 6 bar if the vent is missing.

For air transport, net-weight limits per container apply: 2.5 kg dry ice on passenger aircraft, up to 200 kg per package on cargo aircraft. Our standard containers are sized so the authorised load is clearly documented and the packaging matches the UN certification (4G or 4H2 marking).

An often overlooked aspect is CO₂ concentration in the cargo hold. On longer transports with high dry-ice loads, CO₂ can rise above 5 % — dangerous for drivers and handlers. Our containers have a documented sublimation rate from which the necessary ventilation rate can be calculated precisely.

Since 2020 the −70 °C cold chain for mRNA vaccines (Pfizer-BioNTech: −90 °C to −60 °C) has been a pharma-logistics headline. Active cooling (ULT freezers) requires power, monitoring and maintenance; passive dry-ice cooling is infrastructure-independent and ideal for the last mile or as redundancy during power outages.

Our pharma-grade dry-ice containers meet GDP (Good Distribution Practice) and WHO-PQS requirements: conditioned interiors with reproducible temperature distribution, logger slots, and full temperature-mapping documentation. Containers can be individualised for IQ/OQ qualification with customer protocols.

For secondary packaging of cell therapeutics and biologicals we offer insulated inner boxes with USP-Class-VI-certified contact surfaces. That enables a GMP-compliant dry-ice cold chain with documented traceability to the end customer.