Emergency crews evacuated four of Facebook’s buildings in Menlo Park Monday morning after the possible presence of a chemical weapon was detected on mail delivered by the U.S. Postal Service.
Firefighters said that around 11 a.m. their hazardous materials protocol was activated after a package tested three times for sarin gas came back positive twice.
Three of the buildings that were evacuated have since been cleared to repopulate, according to Facebook spokesman Anthony Harrison, but authorities have not yet positively identified the suspicious substance in question.
As of 3:30 p.m., a team was setting up outside 1005 Hamilton Ave., waiting for additional resources to arrive on scene.
Two people handled the package in question, but there are no medical issues to report, and these individuals are not thought to have been exposed to any dangerous materials.
Menlo Park Fire Protection District Fire Chief Harold Schapelhouman said it’s not yet clear whether this situation is a false alarm or a serious threat to public safety.
“We don’t know yet.”
Sarin gas is a clear, colorless nerve agent with no taste or odor that can occur in liquid or vapor form, according to the federal Centers for Disease Control and Prevention.
Exposure is possible through skin or eye contact, as well as inhalation. For more information, people can go to https://emergency.cdc.gov/agent/sarin/basics/facts.asp.