The safe handling and transport of biological materials are regulated to protect public health, laboratory personnel, and transport workers. These regulations establish classifications for various substances based on their potential risks, ensuring appropriate safety measures are in place during their movement. The classification system streamlines procedures for packaging, labeling, and documentation, contributing to a standardized approach in biosafety.
Understanding Biological Substance Category B
“Biological Substance, Category B” refers to infectious substances that, when exposure occurs, are not generally capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals. These substances are assigned the United Nations (UN) identification number UN 3373.
This classification encompasses diagnostic specimens, clinical specimens, certain biological products, and research samples suspected of containing pathogens, provided they do not meet the criteria for a higher risk category. These materials are transported for analysis, investigation, or disease prevention.
Category A Versus Category B
The distinction between Category A and Category B biological substances is based on the severity of risk posed upon exposure. Category A infectious substances are those that, when exposure occurs, are capable of causing permanent disability, life-threatening, or fatal disease in otherwise healthy humans or animals. Examples include highly virulent pathogens like the Ebola virus or highly pathogenic avian influenza virus. These substances are assigned specific UN numbers: UN 2814 for human pathogens and UN 2900 for animal pathogens.
In contrast, Category B substances, identified by UN 3373, pose a comparatively lower risk. This difference in risk directly influences the strictness of packaging, labeling, and documentation requirements for transport. Category A substances require more rigorous handling and packaging protocols due to their extreme hazard potential, while Category B regulations are designed for materials with a moderate to low risk of harm.
Handling and Transport Requirements
The safe transport of Biological Substance Category B primarily relies on a “triple packaging” system to prevent leakage and exposure. This system consists of three layers: a primary receptacle, secondary packaging, and robust outer packaging. The primary receptacle, which holds the specimen, must be leak-proof and sealed. An absorbent material is placed between the primary and secondary containers to soak up any liquid in case of breakage.
The secondary packaging is a durable, leak-proof container that encloses the primary receptacle and absorbent material. This entire assembly is then placed within a rigid outer packaging designed to protect the contents from physical damage. The outer packaging must have at least one surface with minimum dimensions of 100 mm x 100 mm.
Packages containing Category B substances must be clearly labeled with the UN 3373 diamond-shaped mark, measuring at least 50 mm on each side, along with the proper shipping name “Biological Substance, Category B” displayed adjacent to it. A biohazard symbol should be present on either the primary or secondary container. Documentation requirements include a clear description of the contents and the sender/receiver information, adhering to relevant regulations. Personnel involved in handling these materials must receive appropriate training to ensure compliance and safety.
Everyday Examples
Many commonly encountered biological materials are classified as Biological Substance Category B. Patient blood samples, routinely collected for diagnostic tests, fall into this category. Similarly, urine samples and tissue biopsies taken for diagnostic purposes are also classified as UN 3373.
These materials are transported between clinics, laboratories, and research facilities. Even certain research samples that do not contain highly virulent pathogens are categorized as Category B. The established regulations ensure these biological samples are collected, packaged, and transported safely, minimizing risks to public health and personnel involved.