The building was evacuated as crews worked to contain the spill.
A chemical spill was reported at the Rolls Royce plant early Thursday on the city's west side.
Hazmat crews were called to the 2000 block of South Tibbs Avenue just after midnight on reports of an acid spill.
Officials said the spill happened when three types of acid were mistakenly mixed in an aluminum drum.
The building was evacuated, the spill was contained and no injuries were reported, officials said.