PORTLAND, Ore. (AP) -- Mailroom workers in the lower level of Portland's federal courthouse were evacuated because of concern about white powder found in an envelope. However, the FBI says field tests on the powder have come back negative for any harmful substance.
The powder was sent on Thursday to the Oregon State Public Health lab to determine what it is.
Portland Fire Bureau spokesman Paul Corah tells The Oregonian that officials initially isolated three mailroom workers who might have been exposed to the envelope's contents. No injuries were reported.
Portland police spokesman Sgt. Pete Simpson says the FBI will investigate because the incident happened at the federal courthouse.
Information from: The Oregonian, http://www.oregonlive.com