|This article is about an older version of DF.|
Fire-safe materials are building materials that are not damaged by fire. These include stone, glass, and metal. Wood is not a fire-safe material, and neither are charcoal or coke (even though they are bars). 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 magma versions of these facilities.
Flux materials, such as limestone blocks, 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. Constructions will never melt or burn, regardless of what they're made of, but natural ice walls/floors/ramps/stairs will melt.
Fire-safety is supposed to require the item's material to be stable at the temperature ice is considered to be fire-safe.(i.e. MELTING_POINT/BOILING_POINT/IGNITE_POINT/HEATDAM_POINT greater than 11000 and COLDDAM_POINT less than 11000); due to a bug, however, it only requires that the material is incapable of burning (by having its IGNITE_POINT set to 'NONE'). For this reason,
This is not to be confused with magma-safe materials; many fire-safe materials will still melt when submerged in magma. Generally, though, using fire-safe materials is sufficient for buildings that are powered by magma or items like doors or floodgates that may be adjacent to or in contact with magma, but are never surrounded on all sides by it.