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This page describes products and general use; it is not medical advice.
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An insulated shipping container is a passive, insulated box that slows heat transfer so a load stays inside a temperature range for a stated time, with no power supply. This guide is for clinic staff, lab and procurement buyers and students who need to read a container data sheet: what the product class is, how its performance is defined and tested, and which documents to ask a supplier for.
What it is
In this guide, an insulated shipping container means a parcel-size passive shipper: an insulated box that holds a payload plus conditioned packs. The same words also describe insulated freight containers of the intermodal, refrigerated kind. Those are a different product class and are not covered here.
The World Health Organization’s Performance, Quality and Safety (PQS) programme groups this class as “cold boxes, vaccine carriers and other passive, insulated containers used primarily for the transport” of vaccines, with some used for temporary storage (WHO PQS category E004, checked 3 November 2026). Who uses it: immunization programmes, clinics, labs and distributors moving temperature-sensitive supplies. For the wider shipping picture see cold chain medical supplies shipping and the cold chain definition.
How it is built
A passive container has no refrigeration unit. Its job is done by insulated walls, a lid that seals, and conditioned packs inside. The WHO PQS cold box specification (an earlier edition, issue dated 21 May 2010) sets requirements for the lid seal, hinges, handles, stacking, ingress protection rating, casing material, insulation foaming agents, labels, instructions, verification, the product dossier and incoming inspection. Those headings are a useful list of what a well-documented container should address.
Three pack types are defined in that specification:
- Ice-pack: a water-pack frozen to between -5 and -20 °C.
- Cool-pack: a water-pack pre-cooled to between +2 and +8 °C.
- Warm-pack: a pack stabilized at up to a maximum of +24 °C.
Types and variants
WHO PQS lists these passive container specifications under category E004 (checked 3 November 2026):
| PQS specification | Type | Key difference stated by WHO |
|---|---|---|
| CB01.3 | Vaccine cold box | Base cold box specification |
| CB02.1 | Large capacity vaccine cold box | Large-capacity cold box |
| CB03.1 | Cold box, long-term storage | Long-term storage of 35 days |
| CB04.1 | Cold box, long-term storage | Long-term storage of 10 days |
| CB05.4 | Cold box with freeze-prevention technology | Built to prevent freezing |
| CB06.1 | Ultra-low temperature storage | Provisional specification |
| VC01.2 | Vaccine carrier | Carrier format; maximum loaded weight 8 kg |
| VC02.1 | Vaccine carrier with freeze-prevention technology | Built to prevent freezing |
These are WHO’s categories for vaccine use. Commercial parcel shippers are sold under other names, so ask which standard, if any, a product was tested against.
Specifications that matter
How performance is defined
A data sheet number such as “48 hours” means little without its test conditions. The earlier WHO cold box specification defines three measures (checked 3 November 2026):
| Measure | Starting condition | End point |
|---|---|---|
| Cold life | Empty container stabilized at +43 °C, loaded with ice-packs; timed from lid closing at constant +43 °C ambient | Warmest point in the storage compartment first reaches +10 °C |
| Cool life | Cool-packs stabilized at +5 °C for at least 24 hours; +43 °C ambient | Warmest point first reaches +20 °C |
| Warm life | Container at +18 °C with warm-packs; ambient -20 °C | Coldest point reaches 0 °C |
The same specification gives a minimum cold life of 48 hours for short-range and 96 hours for long-range cold boxes; it sets no standard for cool life or warm life, saying only that performance data will be published. The WHO category page for the current specifications uses the same cold-life end point (warmest point reaching +10 °C) and a +43 °C test ambient.
Capacity and weight
The earlier specification measures vaccine storage capacity by packing 100 x 100 x 100 mm and 100 x 100 x 50 mm test blocks; the total volume in litres is the net storage volume. The WHO category page states that vaccine carriers are designed for a maximum fully loaded weight of 8 kg or less and cold boxes 50 kg or less, and that a worker should not be asked to lift a load greater than 25 kg.
How to choose and verify
These criteria come from the WHO specification and CDC guidance; they are checks, not a ranking of products.
- Match the temperature range to the product. The container must be tested against the range your product needs; see 2 to 8 degrees Celsius shipping for medical supplies.
- Read the test conditions behind each hold time: ambient temperature, pack type and conditioning, and the end point used.
- Ask for the product dossier and data sheet. WHO’s specification includes verification and a product dossier as requirements.
- Check the fully loaded weight against the 25 kg lifting guidance on the WHO category page.
- Use a digital data logger. CDC guidance recommends data loggers for routine storage, transport and temporary clinics.
For carrier and packaging questions see the cold chain shipping vendor evaluation guide. For transit-test standards see ISTA 3A.
Safe use and handling basics
- Condition packs to the type and temperature the data sheet specifies before loading; ice, cool and warm packs behave differently.
- CDC’s vaccine storage and handling update notes that dry ice should never be used for vaccine transport. Dry ice for other goods is a regulated material; see dry ice shipping regulations and what is dry ice.
- Follow the manufacturer’s instructions for use for the specific container and product.
Common mistakes
- Treating a hold time as universal when it was measured at one ambient temperature with one pack type.
- Comparing a cold life figure (end point +10 °C under WHO’s test) with a figure that uses a different end point.
- Confusing parcel-size insulated shippers with insulated freight containers.
- Using dry ice for vaccine transport, which CDC says should never be done.
FAQ
What is an insulated shipping container?
It is a passive insulated box that keeps a payload in a temperature range for a limited time using conditioned packs rather than a power supply. WHO describes cold boxes, vaccine carriers and similar containers as passive, insulated containers used mainly for transport.
How is cold life measured?
Under the earlier WHO cold box specification, an empty container is stabilized at +43 °C, loaded with ice-packs, and timed from lid closing until the warmest point in the storage compartment first reaches +10 °C at a constant +43 °C ambient.
How heavy can a loaded container be?
WHO gives a maximum fully loaded weight of 8 kg for vaccine carriers and 50 kg for cold boxes, and says workers should not be asked to lift more than 25 kg.
Sources
All sources checked 3 November 2026.
- WHO PQS, category E004: cold boxes and vaccine carriers: https://extranet.who.int/prequal/immunization-devices/e004-cold-boxes-and-vaccine-carriers (specification list, cold-life end point, 8 kg, 50 kg and 25 kg weights).
- WHO PQS, performance specification E004/CB01.2: vaccine cold box (issue dated 21 May 2010; an earlier edition): https://extranet.who.int/prequal/key-resources/documents/pqs-performance-specification-e004cb012-vaccine-cold-box (cold, cool and warm life definitions, pack ranges, capacity test blocks).
- CDC, Vaccine Storage and Handling: https://www.cdc.gov/vaccines/hcp/storage-handling/index.html (key-updates summary: dry ice, data loggers).
