On the recordJanuary 29, 2002
The designation of a terrorist attack zone would be made by the President. Once you get past the rescue mission, the immediate response, and when the zone is designated a recovery scene, the tax exemption ends. The intent is for this to benefit those who rush in when there is still an opportunity to save a life; those first responders who themselves are endangered by the initial attack. I would not imagine that would last for anymore than a month. And again, it is validated on a monthly basis, like the combat zone tax exemption.
Source
govinfo.gov




