Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by form]
6. [materials by chemical form]
7. compounds (materials)

Anotations

Scope note:

Any salt or ester of a phosphonic acid. Phosphonates have been tested in recent years as potential crystallization inhibitors for sodium sulfate, a soluble salt that damages historic buildings and sculptures.