New 95kPa Rule for UN3373: Is Your Biological Sample Transport Safe?

As regulatory frameworks for biological sample transport continue to evolve globally, packaging compliance has become a critical industry focus.

Effective this month, two new standards directly impacting the biological sample transport packaging sector have come into force, introducing stricter requirements for packaging pressure tolerance, labeling specifications, and quality control.

Among these, WS/T 852-2025 "Standard for Transport of Infectious Substances" explicitly mandates that primary or secondary packaging for liquid substances must withstand internal pressure of 95 kPa without leakage—a technical parameter that has become a crucial benchmark for UN3373 packaging compliance.

Key Updates in Regulatory Standards

The second half of 2025 has witnessed significant regulatory updates in the field of biological sample transport, encompassing packaging pressure testing, labeling protocols, and quality control requirements.

WS/T 852-2025, as the latest guideline for transporting infectious substances, provides detailed specifications for packaging systems.

The standard formally defines the responsibilities and technical requirements for each layer of the three-tier packaging system, emphasizing primary container integrity at temperatures as low as -18°C.

Secondary packaging must contain sufficient absorbent material with capacity not less than the total volume of primary containers.

Notably, the standard specifically requires that primary or secondary containers for liquid substances must withstand 95 kPa internal pressure without leakage—a requirement exceeding previous industry practices.

Implementation of National Cell Transport Standard

Concurrently, GB/T 45743-2025 "General Requirements for Cell Transport of Biological Samples" officially took effect on September 1, 2025, filling a regulatory gap in the field of cell transportation within China.

This national standard applies to the transport of cells for research and testing purposes, clarifying requirements for transport container selection, labeling protocols, operational procedures, and contingency management.

The document particularly emphasizes risk management and quality assurance during transport, requiring the establishment of corresponding verification mechanisms.

With the implementation of this standard, the standardization level of cell transport activities is expected to significantly improve, providing enhanced safety assurance for biological sample logistics.

Technical Significance of 95kPa Pressure-Resistant Packaging

Within the new regulatory framework, 95kPa pressure resistance has emerged as a critical indicator for evaluating the reliability of biological sample transport packaging.

This pressure threshold—equivalent to approximately 0.95 atmospheres of additional pressure—simulates extreme environmental conditions that may occur during transport, including atmospheric pressure variations, physical impacts, and temperature fluctuations.

Packaging systems that meet the 95kPa pressure test ensure that primary and secondary containers will not rupture due to pressure differentials during air transport or long-distance ground shipping, thereby preventing content leakage or cross-contamination.

For Category B biological substances classified under UN3373, including diagnostic specimens and research cells, this technical parameter directly impacts biosafety throughout the supply chain.

Evolution of Packaging Testing Standards

The IATA DGR 63rd Edition has modified testing requirements for UN3373 packaging, currently focusing primarily on low-temperature drop testing and integrity testing.

Compared to UN2814 substances, which still require multiple tests including drop, integrity, stacking, and puncture tests, UN3373 requirements, while simplified, maintain container integrity as a core assessment criterion.

The newly released WS/T 852-2025 standard also introduces updated UN marking requirements, specifying that outer packaging must include manufacturing year information (e.g., "25" for 2025), facilitating compliance verification by regulatory bodies and end-users.

These changes reflect the industry's increasing emphasis on packaging integrity and traceability.

Regulatory compliance in biological sample transport packaging now extends beyond the conventional three-tier packaging structure, with 95kPa pressure resistance emerging as a key differentiator for product quality.

As new technologies and application scenarios continue to emerge, packaging solutions meeting the highest standard requirements will gain increasing market preference.

Visit www.un3373package.com to understand how our 95kPa pressure-tested packaging solutions meet the latest regulatory requirements, or contact our specialist team for customized compliance solutions.