TULSA, Oklahoma - After a few hours of cleanup, things are getting back to normal at the BeavEx building. 

The Tulsa Fire Department tells us less than a half gallon of desensitized nitroglycerin spilled at the company near Pine and 169 around 8:00 a.m. 

They evacuated employees and are monitoring a man who may have had contact with the chemical. We've just learned employees were just allowed back inside. 

TFD used an absorbent to contain the spill. 

"Which is not as flammable or explosive as regular nitroglycerin, but out of an abundance of caution, we've damned off the area around there," said TFD spokesperson. 

Firefighters weren't sure how the chemical was spilled on the floor.