A sample of blood taken from an individual whose medical history is not available would be classified as which category?

• A. Diagnostic specimen
• B. Category B
• C. Exempt patient specimen
• D. Not regulated

Answer: (B)

The key idea is treating specimens with unknown infectious risk with the appropriate safety category. If you don’t have the patient’s medical history, you can’t rule out the possibility that the blood sample could contain infectious material. In shipping regulations, such a sample is placed in the Category B category (biological substance, Category B, UN 3373) to ensure it’s packaged and labeled to protect handlers and the environment, even though it isn’t classified as a high-risk Category A substance.

Exempt patient specimen would apply only when there’s evidence the sample poses no infectious risk, which you can’t assume here. Not regulated would be inappropriate because unknown infectious potential means some regulatory controls are required. A diagnostic specimen describes the purpose of testing, not its regulatory risk level, and doesn’t automatically determine how it must be shipped.