Sin-Offering: when for a Priest or the Congregation, the Skin, Carcass,
Source: TTT
Leviticus 4:11, 12, 21
But the hide of the bull and all its flesh, with its head and legs and its entrails and dung— / all the rest of the bull—he must take outside the camp to a ceremonially clean place where the ashes are poured out, and there he must burn it on a wood fire on the ash heap. / Then he is to take the bull outside the camp and burn it, just as he burned the first bull. It is the sin offering for the assembly.
Leviticus 6:30
But no sin offering may be eaten if its blood has been brought into the Tent of Meeting to make atonement in the Holy Place; it must be burned.
Leviticus 9:11
But he burned up the flesh and the hide outside the camp.