For the TB Sputum sample, which option indicates Category B as the classification?

• A. UN3373
• B. Category A
• C. Category B
• D. Non-infectious

Answer: (C)

When shipping infectious substances, there are two main categories to decide between: Category A for high-risk pathogens that require the most stringent packaging, and Category B for diagnostic or clinical specimens that may be infectious but are not considered high risk. A TB sputum sample collected for diagnostic testing falls into the latter: it is a clinical specimen that may contain infectious materials, but it is not a known high-risk pathogen requiring Category A packaging. Therefore the appropriate classification is Biological Substance, Category B. The UN number often associated with this category is UN 3373, but the test question is asking for the category itself. Non-infectious would be incorrect because the sample can contain infectious material, and Category A would be reserved for more hazardous, high-consequence pathogens.