How many numbered hazard classes appear in the AAMVA hazard class table (Figure 4.1), and how many additional categories have no class number at all?

AAMVA CDL Manual Section 4.2.1, Figure 4.1, p. 4-2

The hazard class table is the reference drivers use to recognize what they're looking at on a shipping label. Knowing it covers nine numbered classes plus two special unnumbered categories helps a driver understand that a missing number on a label (like ORM-D) doesn't mean the material is unregulated.