Tohoros 2:2-3

Tohoros 2:2

Rabbi Eliezer says that one who eats food of first-degree impurity is rendered unclean in the first decree; of second-degree impurity, in the second degree; of third-degree impurity, in the third degree. Rabbi Yehoshua says that one who eats food of first- or second-degree impurity is rendered unclean in the second degree; of third-degree impurity, he is rendered unclean in the second degree for sanctified food (kodesh) but not for trumah. This applies to non-sanctified food (chulin) that was prepared with the level of purity appropriate to trumah.

Tohoros 2:3

First-degree impurity in chulin is unclean and conveys impurity; second-degree impurity invalidates but does not convey impurity. Third-degree impurity may be eaten in a stew with trumah.