Perbromic acid is any oxyacid (an acid containing oxygen) with the chemical formula HBrO4. It is highly unstable and is created through the protonation of a perbromate (BrO4-) ion. It is also known as hydroxidotrioxidobromine.
Perbromic acid is formed when a proton (a hydrogen atom without an electron) reacts with perbromate. It is a halogen oxyacid and is the least stable of all acids under the same class. As an acid, its most hazardous attribute is its powerful oxidizing properties. When left standing, it quickly decomposes into bromic acid and oxygen. When perbromic acids react with bases, they will form perbromate salts.