How Are Medical Samples Transported? The Role of UN3373 Transport Specimen Bags

The transportation of medical samples, such as blood, urine, swabs, and tissue, is a vital process in healthcare, diagnostics, and research. These samples must be transported safely to ensure accurate test results, protect public health, and comply with stringent regulations. A key component in this process is the use of UN3373 transport specimen bags, designed specifically for Biological Substance, Category B. This guide explores how medical samples are transported, focusing on the role of UN3373 specimen bags, packaging requirements, labeling, documentation, and regulatory compliance.

What is UN3373?

UN3373 is the United Nations classification for "Biological Substance, Category B," which includes diagnostic specimens transported for investigation or diagnosis. These specimens, such as blood, urine, or swabs, are not known to contain highly infectious pathogens but may carry low-risk pathogens. The classification is determined by the shipper, based on factors like the patient’s medical history, symptoms, and local conditions. If a sample is suspected to contain a high-risk pathogen, it may be classified as Category A (UN2814 for humans or UN2900 for animals) instead.

UN3373 samples are typically used for routine diagnostic tests, such as monitoring cholesterol, blood glucose, or organ function, as well as for research purposes. The classification ensures that these samples are handled with appropriate precautions without the stricter requirements applied to Category A substances.

Packaging Requirements for UN3373

To prevent leaks, spills, or contamination during transport, UN3373 substances must be packaged using a triple packaging system, as outlined in regulations like Packing Instruction 650 of the ADR (GOV.UK UN3373 Guidance) and IATA Dangerous Goods Regulations. The system consists of three components:

1. Primary Receptacle

• Function: Directly holds the medical sample.

• Requirements:

  • For liquids, it must be leak-proof and withstand an internal pressure of 95 kPa.

  • For solids, it must be sift-proof to prevent the release of fine particles.

  • Examples include blood tubes, specimen containers, or swabs.

• Standards: Must be securely closed to prevent leakage.

2. Secondary Packaging

• Function: Encloses the primary receptacle and provides an additional layer of containment.

• Requirements:

  • Must be leak-proof for liquids or sift-proof for solids.

  • For liquids, include absorbent material sufficient to absorb the entire contents of the primary receptacle.

  • If multiple primary receptacles are used, they must be individually wrapped or separated to prevent contact.

• Role of Specimen Bags: UN3373 transport specimen bags are often used as the secondary packaging, containing the primary receptacle and absorbent material.

3. Outer Packaging

• Function: Protects the contents during transport and provides a surface for labeling.

• Requirements:

  • Must be sturdy and have at least one surface with minimum dimensions of 100 mm x 100 mm.

  • Must withstand a drop test from 1.2 meters without leakage or damage to the primary receptacles.

  • Either the secondary or outer packaging must be rigid.

• Examples: Fiberboard boxes or rigid containers.

Additional Considerations

• Refrigerated or Frozen Samples: Ice or dry ice must be placed outside the secondary packaging in a leak-proof container. The packaging must maintain integrity at the refrigerant’s temperature.

• Overpacks: If multiple packages are placed in an overpack, UN3373 markings must be visible or reproduced on the overpack.

The table below summarizes the packaging requirements:

Role of UN3373 Transport Specimen Bags

UN3373 transport specimen bags are a critical part of the secondary packaging layer. These bags are designed to meet the stringent requirements for transporting Biological Substance, Category B, ensuring containment and compliance. Key features include:

• Material: Typically made of polyethylene, offering high chemical compatibility and durability (Adsure Specimen Bags).

• Puncture Resistance: Protects against damage during handling or transport.

• Leak-Proof Design: Prevents leaks from reaching the outer packaging.

• Absorbent Material: For liquids, bags often include or accommodate absorbent pads to contain spills.

• Customization: Available in various sizes, colors, and styles, with features like tamper-evident seals, biohazard symbols, or pre-printed UN3373 labels.

• Compliance: Meets FDA and international regulations, such as IATA and ADR.

Specimen bags ensure that the primary receptacle is securely contained, reducing the risk of contamination and ensuring compliance with transport regulations. They are widely used in hospitals, laboratories, and research facilities for transporting samples like blood vials, swabs, and tissue samples.

Labeling Requirements

Proper labeling is essential to communicate the nature of the contents and ensure safe handling. The outer packaging for UN3373 substances must include:

• A diamond-shaped mark (50 mm x 50 mm) with lines at least 2 mm wide and letters/numbers at least 6 mm high.

• The proper shipping name "BIOLOGICAL SUBSTANCE, CATEGORY B" adjacent to the diamond, with letters at least 6 mm high.

• The mark can be handwritten, pre-printed on a label, or printed directly on the packaging.

• If an overpack is used, the UN3373 mark must be visible or reproduced on the overpack.

The labeling ensures that all handlers, from couriers to laboratory staff, are aware of the package’s contents and handle it appropriately. Incorrect or missing labels can lead to delays or rejection by carriers.

Documentation

The documentation requirements for UN3373 are less stringent than for Category A infectious substances. Key points include:

• Shipper’s Declaration for Dangerous Goods: Not required for UN3373 (UN3373 Regulations).

• Labeling and Packaging: Must be fully compliant with UN3373 standards.

• International Shipments:

  • Commercial Invoices: Typically, five copies are recommended for international shipments (Shipping UN3373 Safely).

  • Electronic Export Information (EEI): Required for shipments valued over $2,500 or subject to licensing.

• Carrier Notification: When scheduling pickup with carriers like FedEx or UPS, inform them that the shipment contains UN3373 substances, as only certified drivers can handle hazardous materials.

Proper documentation ensures smooth transport, especially for international shipments, and helps avoid delays or penalties.

Proper Handling and Use of UN3373 Transport Specimen Bags

To ensure safe and compliant transport, follow these steps when using UN3373 transport specimen bags:

1. Select the Appropriate Bag:

   • Choose a UN3373-compliant specimen bag suitable for the sample type (liquid or solid).

   • Verify that the bag meets FDA and international standards.

2. Prepare the Primary Receptacle:

   • Ensure the primary receptacle (e.g., blood tube, swab) is securely closed and leak-proof or sift-proof.

3. Place the Primary Receptacle in the Specimen Bag:

   • Insert the primary receptacle into the specimen bag, ensuring it is fully enclosed.

4. Add Absorbent Material (for Liquids):

   • Include sufficient absorbent material to absorb any potential leaks, placed between the primary receptacle and the bag.

5. Seal the Specimen Bag:

   • Close the bag securely, using tamper-evident seals if required.

6. Place in Secondary Packaging:

   • If additional secondary packaging is used, place the bagged primary receptacle inside it with extra absorbent material.

7. Pack in Outer Packaging:

   • Place the secondary packaging in a sturdy outer container that meets the 100 mm x 100 mm dimension requirement.

8. Label the Outer Packaging:

   • Affix the UN3373 diamond-shaped mark and "BIOLOGICAL SUBSTANCE, CATEGORY B" label on the outer packaging.

9. Prepare Documentation:

   • Ensure all necessary documents, such as commercial invoices for international shipments, are completed.

10. Schedule Pickup:

    • Notify the carrier (e.g., FedEx, UPS) that the shipment contains UN3373 substances to ensure a certified driver handles the package.

Regulations and Guidelines

The transportation of UN3373 substances is governed by several international and national regulations, including:

• IATA Dangerous Goods Regulations (DGR): Governs air transport, ensuring compliance for international shipments (UN3373 Category B).

• ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road): Applies to road transport in Europe, specifying Packing Instruction 650.

• DOT (Department of Transportation) Regulations: Regulates transport within the United States, aligning with IATA for air shipments.

These regulations outline packaging, labeling, and documentation requirements. Shippers must stay updated with the latest versions to ensure compliance, as regulations may vary slightly by region or transport mode. Training, such as IATA/DOT hazardous materials training, is recommended for personnel handling UN3373 shipments (Georgetown University EHS).

Special Considerations

• Temperature-Sensitive Samples: Samples requiring cold chain transport (e.g., +2°C to +8°C or below -18°C) must use insulated packaging with refrigerants like dry ice or ice packs (Sofrigam UN3373 Packaging). The packaging must maintain the required temperature without compromising integrity.

• Spill Response: If a spill occurs, the transport unit must be cleaned, disinfected, or decontaminated, and other goods checked for contamination.

• Exemptions: Substances unlikely to cause disease (e.g., samples for cholesterol monitoring) may be exempt from UN3373 requirements unless they meet criteria for another hazard class.