Firefighters arrived at the fire at Uniseal, located on the 1800 block of West Maryland Street, around 2:30 Thursday afternoon.
The company makes adhesives and sealants for vehicles and fire crews say the wrong chemicals were put together in a mixer and it generated too much heat, then flames.
They say the fire began on the first floor and smoke traveled to the second floor through a vent.
Extra companies were called due to the complexity of the building, but firefighters say all the employees got out okay and no one was injured.
Firefighters say the mixer is totally destroyed but aside from that, there's only some smoke damage to the second floor.