Emergency crews were on the scene near Irving Park Road and Taft around 7:30 a.m. at the Lufthansa cargo facility.
Officials said there was no danger from the spilled material. Firefighters had feared that a radioactive material had spilled from a crushed container.
The hazardous materials team was called in to investigate as a precaution. It is unclear what spilled, but the substance has been determined not to be radioactive.
Two workers were exposed to the substance but are expected to be OK.
The situation was not in a terminal or in the airport itself, according to fire department spokesperson Rich Rosado.