Keilim 8:6-7

Keilim 8:6

If a pot for leaven that has a tight lid is put into an oven, then if the leaven and a sheretz (vermin) are in separate compartments within the pot, the oven is rendered ritually unclean but the leaven remains ritually clean. If there was an olive-sized piece of a corpse in the pot’s other compartment (instead of a sheretz) then both the oven and the house are rendered unclean but the leaven remains ritually clean. If there’s a handbreadth-sized hole between the pot’s compartments, then everything is rendered unclean.

Keilim 8:7

Let’s say that a sheretz was found in the exhaust vent of an oven, stove or mini-stove. If it’s located from the inside edge of the vent and outward, then the oven or stove remains ritually clean. If it’s in the air, then it remains clean even if in the case of an olive-sized piece from a corpse. If there’s a handbreadth-sized opening in the vent, then both the vent and the oven are rendered ritually unclean.