Despite vanilla blocks not being able to be smelted in a blast furnace or nuclear furnace (e.g. sand is not able to be smelted into glass from a blast furnace or nuclear furnace without the respective config being turned off), Scrap Metal, Smooth Limestone, Smooth Bone Blocks, Guanostone and Smooth Coprolith can still be smelted from their base ingredients in both furnaces.

While Unrefined Waste and Packed Galena can also be put into a Blast or Nuclear Furnace, these may be intentional as they smelt into Uranium Shards and Iron Nuggets respectively.