UN3373 Category B
Compliant Shipping
Blood, stool, and urine specimens fall under UN3373 Biological Substance, Category B — and shipping them wrong risks rejected packages, fines, and lost samples. Compliance is our baseline, not an add-on.
What UN3373 Category B Means
UN3373 “Biological Substance, Category B” is the DOT/IATA classification covering most patient specimens shipped for diagnostic purposes — blood, stool, urine, swabs, and saliva. These shipments must follow the triple packaging system: a leak-proof primary receptacle, leak-proof secondary packaging with absorbent material, and rigid outer packaging displaying the UN3373 diamond mark and the words “Biological Substance, Category B.”
Carriers reject improperly packaged Category B shipments, and repeated violations bring regulatory exposure. Every specimen-related kit that moves through Focus Hard Medical Logistics is handled under UN3373-compliant procedures as a matter of standard operating procedure.
Our UN3373 Compliance Standards
- Triple packaging verification — primary receptacle, secondary leak-proof barrier with absorbent, rigid outer box on every specimen shipment.
- Correct marking and labeling — UN3373 diamond, proper shipping name, and orientation handled on every package.
- Carrier-specific requirements — packaging configured to USPS, FedEx, and UPS rules for Category B substances.
- Documented procedures — written SOPs govern specimen kit handling from receipt to dispatch.
- Trained handling — DOT hazmat-aware processes for every team member who touches Category B shipments.
Specimen Kit Programs
Outbound collection kits with compliant return packaging included, ready for the patient or clinic to send back.
Compliant Returns
Inbound Category B specimens routed back to your lab in full compliance via USPS Priority Mail or your carrier.
Packaging Consultation
Not sure if your current kit packaging meets Category B rules? We will review it against current requirements.
Exempt Specimens Too
We also handle exempt human specimen shipments where Category B rules do not apply — classified correctly, every time.
Why Labs Choose a Compliance-First Partner
Many general fulfillment warehouses simply will not touch specimen logistics — or worse, they handle it without understanding the rules. We built our entire operation around medical-grade logistics in Northern New Jersey: UN3373 Category B compliance, chain-of-custody thinking, and documentation labs can show their own auditors.
Frequently Asked Questions
Is UN3373 the same as a hazmat shipment?
Category B biological substances are dangerous goods with simplified requirements — they do not need a full hazmat shipping paper, but they must follow the triple packaging, marking, and labeling rules of 49 CFR 173.199 / IATA PI 650.
Which specimens count as Category B?
Most patient specimens being shipped for diagnostic or investigational purposes — blood, urine, stool, swabs — unless they qualify as exempt human specimens or are suspected Category A infectious substances (which we do not handle).
Do you supply UN3373-compliant packaging?
Yes. Kits can be assembled with compliant return packaging included, so your patient or clinic ships back correctly without thinking about it.
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