Medical Specimen Shipping: Biological Substance Category B UN3373 Guide

Shipping Medical Specimens as Biological Substance Category B

Medical diagnostic specimens including blood samples, tissue biopsies, and body fluid collections are frequently shipped as Biological Substance Category B (UN3373) under IATA DGR and DOT regulations. Proper classification and packaging of these specimens protects laboratory workers, transportation personnel, and the integrity of diagnostic results.

Category A vs. Category B Classification

Category A biological substances (UN2814/UN2900, Class 6.2) are known or reasonably expected to cause permanent disability, life-threatening disease, or fatal disease in humans or animals. Category B (UN3373) encompasses all other biological substances that do not meet Category A criteria. Most routine diagnostic specimens fall under Category B, which has significantly less restrictive shipping requirements than Category A.

Triple Packaging Requirements

UN3373 shipments require the triple packaging system: a leak-proof primary receptacle (specimen container), a leak-proof secondary packaging (sealed bag or container), and a rigid outer packaging meeting specified performance standards. Absorbent material sufficient to absorb the entire contents must be placed between primary and secondary packaging. The completed package must pass a 1.2-meter drop test.

IATA P650 Packing Instruction

IATA Packing Instruction 650 governs Category B biological substance air transport. The instruction specifies packaging construction, marking requirements (UN3373 diamond mark and “BIOLOGICAL SUBSTANCE, CATEGORY B” label), and documentation provisions. Unlike most dangerous goods, UN3373 shipments do not require a Shipper’s Declaration, simplifying air freight processing.

Cold Chain for Specimen Integrity

Many medical specimens require temperature control to maintain diagnostic viability. Gel packs, wet ice, or dry ice may be used as refrigerants. When dry ice is included, it must be declared separately as UN1845 (Class 9) with its own marking and documentation requirements. Ground transport of specimens with temperature monitoring provides chain-of-custody documentation for laboratory accreditation compliance.

Hospital and Laboratory Networks

Healthcare systems ship specimens between collection sites, reference laboratories, and specialty testing facilities daily. Logistics coordination for specimen transport must balance transit time (affecting diagnostic viability) with hazmat compliance. Collection point management and courier network design optimize specimen logistics for healthcare organizations across South Florida.

Go Freight’s Specimen Logistics

Go Freight provides medical specimen shipping services from South Florida’s healthcare corridor. Our team handles Category B biological substance compliance, cold chain management, and time-critical delivery for diagnostic laboratories and healthcare systems.