However, these exempt sources should not be in direct contact with the skin for extended periods and should not be directly handled if the source appears damaged. Damaged sealed sources and improperly sealed liquids or precipitate residues from chemical experiments using unsealed radioactive material can pose contamination and exposure hazards. Sources manufactured 30 or more years ago may have deteriorated to a point that source integrity may be uncertain. Uranium and Thorium Compounds Uranium oxide was commonly used to color ceramics. Uranium oxide is usually in the form of a fine powder that can present potential inhalation, ingestion, and contamination hazards.
Exposure also can result from holding a jar or bag of the material for an extended period of time.
Uranium nitrate was used as a component of the toners and intensifiers for developing photographs. Uranium acetate and uranium nitrate were used during the staining process for electron microscope slides. Uranium ore can also be found in schools. Thorium nitrate was used for solution color change demonstrations in chemistry classes. Thorium oxides were also commonly available for study in natural science classes.