The office of the Boston Fire Department’s Fire Prevention Division was evacuated and shut down when an envelope containing a powdery substance was opened early Thursday afternoon, the department said.
Firefighters responded to the fourth-floor office at 1010 Massachusetts Ave. just after 1 p.m., Boston fire and police said. The area where the envelope was opened was isolated and the floor evacuated as crews shut off the building’s air system, Fire Department spokesman Steve MacDonald said in messages posted on Twitter.
He said that all tests on the envelope with white powder had come back negative, but that the envelope would be sent to s state lab for further testing.
An initial test of the area’s air quality by the Boston police Hazardous Materials Unit just after 3 p.m. showed no sign of danger, prompting firefighters to scale down their response, MacDonald said.
People in the building’s five other floors were initially evacuated, though MacDonald said he expected them to be allowed back in later in the day. The building also houses Boston’s Parks and Recreation Department, Public Health Commission, and Inspectional Services.
Officials briefly shut down Massachusetts Avenue from 1010 Massachusetts Ave. to Victoria’s Diner at 1024 Massachusetts Ave. while crews responded, MacDonald said.
In another incident on Thursday, Harvard Law School tweeted around 3:30 p.m. that police were investigating a suspicious package containing white powder that was sent to Hauser Hall on Massachusetts Avenue.
Cambridge Assistant Fire Chief Gerry Mahoney said a hazmat team was investigating the envelope sent to Hauser.
An office worker who opened the envelope and saw the white powder inside quickly washed her hands and called police, he said.
There is no evidence that the package sent to the Boston Fire Department office and the envelope sent to Hauser Hall were related, Mahoney said.
He said students and staff were asked to stay out of Hauser Hall, but that there did not appear to be any danger. The envelope was taken to a state lab for further testing, he said.Globe correspondent Todd Feathers contributed to this report. Lauren Dezenski can be reached at lauren.dezenski@
globe.com. Follow her on Twitter @LaurenDezenski.