Which of the following is NOT used to make toothpaste?

Galena

The correct answer is option 1. Galena.

Galena is NOT used to make toothpaste.

Toothpaste typically consists of abrasives, binders, detergents, humectants, flavoring agents, and sometimes fluoride. The abrasives are the components responsible for cleaning and polishing the teeth. Common abrasive agents in toothpaste include silica, calcium carbonate (which is derived from limestone), and aluminum oxide.

Galena, on the other hand, is a lead ore (lead sulfide, PbS) and is not used in toothpaste. The use of lead-based compounds in consumer products, including toothpaste, is avoided due to the potential health risks associated with lead exposure. Silica, limestone, and aluminum oxide are more commonly used as abrasives or in other capacities in toothpaste formulations.