| thorium dioxide | <chemical> Thorium oxide (tho2). A radiographic contrast agent that was used in the early 1930s through about 1954. High rates of mortality have been linked to its use and it has been shown to cause liver cancer. Pharmacological action: carcinogens. Chemical name: Thorium oxide (ThO2) (12 Dec 1998) |
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| titanium dioxide | TiO2;contains not less than 99.0% and not more than 100.5% of TiO2, calculated on the dry basis; used in creams and powders as a protectant against external irritations and solar rays. (05 Mar 2000) |
| 1,4-diethylene dioxide | 1,4-dioxane;a colourless liquid used as a solvent for cellulose esters and in histology as a drying agent. Synonym: 1,4-diethylene dioxide. (05 Mar 2000) |