UN3172 (Toxins Extracted from Living Sources)
Also: UN3172, UN3462
The Class 6.1 entry for a toxin extracted from a plant, animal or bacterial source and separated from the organism that produced it. UN3172 is the liquid entry and UN3462 the solid.
A toxin on its own is classified as toxic rather than infectious, so it leaves Class 6.2 entirely and the packaging, labelling and declaration requirements change with it.
If an infectious organism is present alongside the toxin, the infectious classification takes precedence and the material is assessed as Category A or Category B in the normal way.