By the Daily Post staff
A suspicious package that arrived at Facebook on Monday set off an alarm for the chemical warfare agent sarin, but further testing by federal officials found no trace of toxic nerve agent, a Menlo Park fire official said this morning.
The package was delivered by the U.S. Postal Service around 11 a.m. to one of the company’s mail rooms in the 1100 block of Hamilton Avenue in the former Prologis Industrial Park off of Willow Road.
The incoming mail goes through a processing machine and the package in question tested positive for sarin. The package was re-tested twice, with one positive and one negative result, fire officials said.
Two people handled the package, but neither has reported any symptoms, and they are not thought to have been exposed to any hazardous materials.
Four buildings were evacuated and three were cleared for people to come back in, said Facebook spokesman Anthony Harrison in a statement.
Later in the day, the FBI took over the investigation, as is standard procedure in such cases, Fire Chief Harold Schapelhouman said. The Hayward-based 95th Civil Support Team, a unit of the California Army National Guard, arrived at the scene, he added. He said the team has the equipment and expertise to determine if the package contains sarin.
At about 9 p.m., Menlo Park Fire Marshal Jon Johnston said the tests by the team were inconclusive.
Between 10 and 11 Monday night, crews re-entered the building and recovered the package, and put it in a mobile containment device and removed it from the area.
More sophisticated detection equipment was used and the presence of sarin was ruled out.