If someone has glass shelves inside of a fridge that food is put on directly (without being inside of a wrapper or some sort of packaging) do the glass shelves then need tevillah?
Because food is not usually placed directly on the shelves, there is no obligation of tevilah for them.
Another reason for the exemption is that the shelves cannot be considered “utensils of the se’udah.” Unlike a salt shaker (for instance), they do not move around, they are not brought to the meal or to the pot, and they take no part in the cooking or eating process.
See the following sources: Tevilas Keilim 11:10, Minchas Shlomo 2:66:8 (exempts shelves because they are not klei se’udah; see also Minchas Yitzchak 9:83), Shalmei Moed page 555 (who writes that the shelves are batel to the refrigerator, and therefore exempt from tevilah).
Be’er Moshe (4:99) writes that shelves are obligated in tevilah, but that one should not criticize those who are lenient.