The term "refractory safe" or "refractory cabinet" appears in older catalogues from brands such as Fichet, Bauche and Haffner. It refers to safes whose walls were filled with refractory materials — materials capable of withstanding high temperatures and slowing the transfer of heat in the event of fire. This technique dates back to Henri Bauche, who from 1864 constructed his safes with two iron casings filled with a refractory compound between them.
Today, the correct term is fire-resistant safe or, where the model also offers certified burglary resistance, fire-resistant safe with burglary protection. The principle of refractory materials in the walls remains present in modern certified models.