Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. biological control agents
7. biocide

Anotations

Scope note:

Refers to any of several commercially prepared oxygen absorbing powders to be deployed in a sealed environment for insect eradication and oxygen-free storage in museums and archives; they are also used to extend the shelf-life of commercial food items. All contain a chemical compound the active ingredient of which is a finely divided iron oxide.