Where The Biological Substance Category B Mark Must Appear On Packages

Biological Substance Category B Mark A package marking used for shipments classified as Biological Substance, Category B.

The Biological Substance Category B Mark identifies packages that contain infectious substances assigned to UN3373 and packaged to meet the specific requirements for Category B shipments. Carriers, shippers, and receiving facilities look for this mark to confirm the package was prepared, labeled, and handled under the applicable regulations for non‑high risk infectious substances.

What The Mark Looks Like

The mark is a standardized symbol and text combination required by many modal regulations. It typically consists of the UN number "UN3373" plus the words "Biological Substance, Category B" or an equivalent phrase depending on the regulation set. The design and minimum size are defined by international and national rules so the mark is legible and clearly visible during transport and inspection.

Required Placement On The Package

Placement rules focus on visibility and association with the consignment information. Key placement rules used by carriers and regulators:

• Surface Placement: The mark must be placed on the outer packaging surface so it is immediately visible without opening the package.
• Near Shipping Information: Place the mark close to or on the same panel as the shipper/consignee address to link the marking to the shipment.
• Clear Of Other Marks: Do not obscure the mark with tape, other labels, or handling instructions. Maintain a clear area so the symbol and text are not obscured.
• Multiple Faces: For irregular packages, place the mark on the two largest opposing sides when possible to ensure visibility regardless of orientation.

Size, Colour, And Durability Requirements

Regulations require minimum sizes and durable application so the mark remains readable after handling. Typical specifications include:

• Minimum Size: The mark must be large enough to be legible — many regulations specify a minimum height for text or symbol (check the applicable modal rules for exact dimensions).
• Contrast: Use colours that contrast with the package background (black on white is common) to ensure legibility.
• Durability: Apply the mark using labels or printing methods that resist smearing, weather, and abrasion during normal transport conditions.

Mode‑Specific Placement Notes

Different transport modes (air, road, mail) reference similar marking rules but may add specifics.

• Air Transport: The mark must be clearly visible and be accompanied by any additional labels or documentation required by the air carrier and IATA Dangerous Goods Regulations.
• Ground Transport: For domestic road transport, federal or state hazardous materials rules apply and visibility during loading/unloading is the priority.
• Mail Services: Postal services may require the mark on a specific panel and limit mailing of certain infectious substances; follow postal publication guidance exactly.

Who Is Responsible For Correct Placement

Primary responsibility lies with the shipper preparing the specimen for transport. Carriers perform acceptance checks and may refuse shipment if the mark or its placement does not meet requirements. Receiving facilities should also verify the mark on arrival before opening or handling the package.

Inspection Checklist For Shippers And Receivers

• Mark Present: Verify the mark is on the outer package and readable before handing to the carrier.
• Location: Confirm the mark is near the shipping addresses or on a main panel, not hidden by tape.
• Size And Contrast: Ensure text and symbol meet the minimum legibility criteria and contrast with the package colour.
• Durability: Use weatherproof labels or printing and test for smearing when wet or abraded.
• Documentation Match: Check that the mark matches the accompanying waybill and any written declarations (UN3373 and Category B references).

Practical Example

A clinical lab ships a blood specimen for diagnostic testing by air. The packer prints a durable label that reads "UN3373, Biological Substance, Category B" in bold black letters (minimum height as required), and applies it to the largest side panel near the recipient address. The label is covered with a clear protective film to resist moisture. At the airport, the cargo handler inspects the label before acceptance to confirm compliance with air carrier acceptance procedures.

In short, the Biological Substance Category B Mark must be visible, durable, and placed so carriers and receiving facilities can immediately identify the package as containing a UN3373, Category B infectious substance. Proper placement reduces acceptance delays, improves safe handling, and ensures regulatory compliance.