Authorities are investigating a suspicious package that was delivered to an office building near the Galleria.
Houston firefighters were called to the Capitol One Building on Westheimer at Bering Drive around 8:30 a.m. Thursday.
Officials say the suspicious package contained light blue powder in an envelope and was found by employees on the fourth floor.
A hazmat team has been called to the scene.
Police say 13 people were exposed to the powder. They are being checked out, and so far, three of them have a slight rash.
Authorities with the Houston fire and police departments are investigating. The FBI has also been contacted.
The material was tested for any type of active ingredient that could be dangerous, but it turned out to be a neutral substance.