Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. additive (material)

Anotations

Scope note:

Any chemical agent added to water that lowers its freezing point, usually to protect a mechanical system from damage. Ethylene glycol or propylene glycol are added to water in automobile cooling systems to prevent damage to radiators.