Most clinical and diagnostic samples you will ever ship travel as Category B biological substances — assigned UN 3373. The category covers material that may contain pathogens but is unlikely to cause disease in healthy humans or animals: routine bloods, swabs, most genetic test samples.
What UN 3373 requires in practice
- Triple packaging: a leak-proof primary receptacle, a 95 kPa-tested secondary container with absorbent, and a rigid outer packaging bearing the UN specification mark
- The UN 3373 label plus the proper shipping name — “Biological Substance, Category B” — and sender/consignee details
- Primary receptacles under 50 ml are not quantity-limited; over 50 ml per receptacle requires extra absorbent and spacing rules
- No shipper's declaration for dangerous goods is required — unlike Category A
- Temperature control (2–8 °C, frozen) rides on top of the compliance rules, not instead of them
If a laboratory tells you to “ship as UN 3373”, this is the checklist behind it. We assemble it daily — and inspect every box against it before sealing.
Tell us what needs to move.
Route, sample, temperature, deadline — we answer with a plan and a quote within one business day.
Request a Quote