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:

Shiny white crystalline compound used in photography as a toner and to remove stains from negatives. Capable of dissolving silver salts, thiourea is often an active ingredient in silver-dip tarnish removal solutions. It is also used to accelerate the vulcanization of rubber. Its composition is the same as that of urea but with a sulfur atom in place of the oxygen atom.