Susceptibility of materials of construction to attack by bromine is very dependent on the process conditions including temperature, pressure, concentration, water content, and what other species are present. Whenever possible materials selected for bromine duty should be tested under the actual conditions of use. Most metals are not suitable for bromine service including titanium. In some limited cases Hastelloy C alloys can be used. Alloys of niobium and tantalum are usually acceptable but high cost restricts their use.