The suspicious package was delivered around 11 am to one of the company’s mail rooms. Two people were being evaluated for possible exposure. The people who came in contact with the suspicious package at about 11am PT (1800 GMT) did not show any symptoms of exposure to sarin, said Jon Johnston, fire marshal for the city of Menlo Park, California. There were no reports of injuries at the site. Sarin, which was used as a chemical weapon, is a chemical warfare agent that is colourless, odourless, and tasteless. A drop of sarin on skin can cause sweating and muscle twitching. Exposure to large doses may result in paralysis and respiratory failure.
The Facebook facility tests all incoming packages and initiated standard protocol after a package tested positive for sarin. Officials at the Menlo Park Fire Protection District arrived at the Facebook headquarters. Agents from the San Francisco office of the Federal Bureau of Investigation were responding to the scene. Later, three of the evacuated buildings have been cleared for repopulation.