Chulin 9:1-2

Chulin 9:1

An animal’s hide, juice, spices, scraps, bones, sinews, horns and hooves all combine to convey the ritual impurity of food but not the ritual impurity of neveila. Similarly, if one slaughters a non-kosher animal for a non-Jew and it jerks (i.e., it’s still alive), it conveys the ritual impurity of food but not the ritual impurity of neveila until it has died or been decapitated. More things convey the ritual impurity of food than the ritual impurity of neveila. Rabbi Yehuda says that if enough scraps are collected so that there’s the volume of an olive in one place, then one is liable to the ritual impurity of neveila.

Chulin 9:2

The following skins are considered like flesh regarding the laws of ritual impurity: that of a human; of a domestic pig – Rabbi Yosi also includes a wild pig; the skin of a young camel’s hump; that of a young calf’s head; of the hoofs; of the womb; of a fetus; the skin beneath the fat tail; that of a hedgehog, a chameleon, a lizard and a snail. Rabbi Yehuda says that a lizard is like a weasel (so its skin is not considered like flesh). All of these, if they were tanned or trod upon for as long as necessary to process them, are ritually pure except for human skin. Rabbi Yochanan ben Nuri says that the eight creeping creatures (sheratzim) have skins.