How To Apply The UN 3373 Mark: Packaging, Placement, And Documentation

UN 3373 Mark must be applied correctly to packages containing Biological Substance, Category B so carriers and emergency responders can identify the shipment and apply appropriate handling procedures. Correct marking is part of a chain that includes classification, packaging, and documentation.

Step 1 — Confirm Classification

Before marking, determine whether the material is Category B. Classification depends on the infectious nature of the sample and the likelihood of causing disease during transport. If the material meets Category A criteria, do not use the UN 3373 Mark; instead follow Category A labelling and declaration rules. If unsure, consult your laboratory biosafety officer, regulatory guidance, or carrier dangerous goods specialists.

Step 2 — Use Approved Packaging

Category B shipments usually employ a triple-packaging system: a primary leak-proof receptacle, sufficient absorbent material, sealed secondary packaging, and a rigid outer packaging. The outer package must protect the contents during handling and transport. Always follow the packing instructions applicable to your mode of transport and the carrier’s specific requirements.

Step 3 — Apply The UN 3373 Mark Correctly

• Location: Affix the UN 3373 Mark on the outside of the package where it is visible and not obscured by tape, straps, or other labels. Place it on a flat surface for readability.
• Legibility: Use printed labels with clear contrast between text and background. Avoid handwritten labels that can become illegible after transit.
• Size And Durability: Ensure the label is durable enough to withstand scuffing, moisture, and abrasion during transit. While specific modal rules may specify minimum sizes, the functional requirement is that the mark remains readable throughout the shipment’s life.

Step 4 — Complete Required Documentation

Although Category B shipments typically do not require a shipper’s declaration of dangerous goods, the transport document (air waybill or bill of lading) must include a proper description such as "Biological Substance, Category B, UN 3373" plus the number of packages, weight, and emergency contact details. Retain copies of the shipment documentation as part of your compliance records.

Step 5 — Follow Carrier Acceptance And Handling Rules

Different carriers and modes have unique acceptance rules. For air transport, consult the IATA Dangerous Goods Regulations and the specific airline’s acceptance instructions. Some couriers require pre-booking or acceptance at designated facilities for biological shipments. Always confirm routes and handling protocols, especially for international shipments where import/export documentation and local regulations may apply.

Common Mistakes And How To Avoid Them

• Mislabeling: Don’t use the UN 3373 Mark for Category A materials. Misclassification can lead to carrier refusal and legal liabilities.
• Poor Label Placement: Avoid putting labels across seams, corners, or on curved surfaces where they can peel off or be unreadable.
• Insufficient Documentation: Missing emergency contacts or inaccurate descriptions are common causes of rejected shipments. Verify that all required fields on transport documents are complete and accurate.

Practical Checklist For Shippers

• Classify: Confirm Category B status before packing.
• Pack: Use leak‑proof primary receptacles, absorbent material, and a rigid outer package.
• Mark: Affix the UN 3373 Mark on the outer packaging in a clearly visible location.
• Document: Complete the transport document with the correct description and emergency contact.
• Train: Ensure shipping staff are trained on modal rules and carrier policies.

In short, the UN 3373 Mark should be used only after proper classification and packaged to regulatory standards. Correct label placement, durable printing, and complete transport documentation ensure safe, compliant movement of Biological Substance, Category B shipments through the transport chain.