Disclosed are glass compositions, glass fiber compositions, glass fiber battery separators, glass fiber filter media, battery additives and active materials formed with glass compositions disclosed, glass fiber radiation shields, and glass fiber paper compositions. Certain embodiments include, among other components, bismuth oxide. Certain embodiments include about 0.5-30% bismuth oxide of the composition by weight and silica oxide at about 54-70% of the composition by weight. Embodiments may also include other components. For example, zinc oxide can make up about 0.01-3% of the composition by weight.