|This article is about an older version of DF.|
Fire-safe materials are those that are not damaged by fire. These materials include glass, metal, and most stone. No types of wood are fire-safe, and neither are charcoal or coke. Bituminous coal and lignite are flammable stone, and therefore not fire-safe. Fire-safe materials are only required when the object is going to come into contact with extreme heat, such as a wood furnace, smelter, forge, kiln or glass furnace, or for the magma-powered versions of these facilities.
Flux materials, such as limestone, which are consumed in the purification of pig iron to produce steel, are considered fire-safe. It is perfectly fine to use limestone as a flux material to make steel in a limestone smelter.
As far as the game is concerned, any material which is stable at the temperature ice being considered fire-safe. Furthermore, the game only considers bars, blocks, stone, logs, and anvils to be capable of being fire-safe in custom reactions and workshops - all other item types are rejected outright. Despite this temperature being considered fire-safe, actual fire can generate temperatures significantly higher (in particular, any burning item will heat up to 200 degrees above its material's ignite point).(i.e. MELTING_POINT/BOILING_POINT/IGNITE_POINT/HEATDAM_POINT greater than 11000 and COLDDAM_POINT less than 11000) is supposed to be considered fire-safe; due to a bug, however, the game only checks that the material has no ignition point, resulting in such oddities as