The Lexington fire department's hazardous materials crew was on scene, and workers were evacuated for more than an hour, after someone found an envelope containing a white powdery substance at the Xerox call center on Yorkshire Drive.
The substance turned out to be correction fluid, such as Wite-Out or Liquid Paper, which had dried on a document, peeled off and fallen into the bottom of the envelope, fire Major Ed Davis said.
The incident was reported about 2:45 p.m. Dozens of workers waited in the parking lot until after 4 p.m.
Davis said calls for suspicious packages and envelopes typically increase when Anthrax cases and hoaxes are in the news. The FBI this week said it thinks a single person is responsible for about 400 powdered letters mailed across the country and abroad over the last four years. The hoax letters have been sent to businesses, schools and homes.
Anthrax-laced letters first became a major public concern in September 2001. Following the 9/11 attacks, letters containing Anthrax spores were mailed to media outlets and public officials, causing five deaths in the first month.