אָסוּר לְטַמֵּא אֶת הַתְּרוּמָה שֶׁל אֶרֶץ יִשְׂרָאִל כִּשְׁאָר הַקָּדָשִׁים וְלֹא יְבִיאֶנָּה לִידֵי טֻמְאָה וְלֹא יַפְסִידֶנָּה אֶלָּא אוֹכֵל הַטְּהוֹרָה וּמַדְלִיק הַטְּמֵאָה. וּמֻתָּר לְטַמֵּא תְּרוּמַת חוּצָה לָאָרֶץ בְּטֻמְאוֹת שֶׁל תּוֹרָה. וְאַף עַל פִּי שֶׁאֵינָהּ טְמֵאָה אֶלָּא בְּאֶרֶץ הָעַמִּים שֶׁהִיא מִדִּבְרֵיהֶם מִפְּנֵי שֶׁעִקַּר חִיּוּבָהּ מִדִּבְרֵיהֶם. לְפִיכָךְ נִדָּה קוֹצָה לָהּ חַלָּה בְּחוּצָה לָאָרֶץ שֶׁאֵינָהּ מֻזְהֶרֶת אֶלָּא לְאָכְלָהּ לֹא לִגַּע בָּהּ כְּמוֹ שֶׁבֵּאַרְנוּ:
It is forbidden to cause the terumah of Eretz Yisrael to contract ritual impurity, as [is the rule with regard to] other sacred articles. One should not bring it to a state of ritual impurity, nor should one spoil it. Instead, he should partake of pure [terumah] and kindle impure terumah. It is permitted to cause terumah from the Diaspora to become impure, even with impurity mandated by Scriptural Law. Although it is only ritually impure because of the impurity stemming from the Diaspora which is a Rabbinic decree, [this leniency is granted] because the obligation to separate [such terumah] is also of Rabbinic origin. For this reason, a woman may separate challah while in the niddah state in the Diaspora, for she is cautioned only against eating it, not against touching it, as we explained.
