Fluoroantimonic acid
This substance is a superacid that can be more than 1015 times stronger than pure sulfuric acid, depending on the proportion of its ingredients. Extreme care must be taken when handling and storing fluoroantimonic acid, as it is exceptionally corrosive. For example, it cannot be contained directly in glass containers as it will dissolve glass, but can be stored in containers lined with PTFE (Teflon).