It forms unstable yellow[2] to yellow-orange[1] crystals.

It was first isolated by R. Schwarz and M. Schmeißer in 1937 and is hypothesized to be important in the atmospheric reaction of bromine with ozone.

[3] It is similar to chlorine dioxide, the dioxide of its halogen neighbor one period higher on the periodic table.

[citation needed] Bromine dioxide is formed when an electric current is passed through a mixture of bromine and oxygen gases at low temperature and pressure.

[1] When mixed with a base, bromine dioxide gives the bromide and bromate anions:[4]