Which label set would be considered correct for a Category B package?

• A. UN 3373 Diamond-on-point marking
• B. Dry ice label
• C. Class 6 hazard label
• D. None of the above

Answer: (A)

Labeling Category B shipments requires the UN 3373 mark, which identifies Biological Substance, Category B. This diamond-on-point symbol is the standard indicator that the package contains an infectious substance of Category B and that it must be handled and shipped under the proper packaging and transport rules. The dry ice label would only come into play if dry ice is used as a refrigerant, and it wouldn’t by itself designate Category B. A Class 6 hazard label points to a broader hazard category and isn’t the specific identifier for Category B infectious substances.