The order was issued by Georgetown police around 7 p.m. Wednesday due to a "hazardous materials incident" at the plant located on Savanna Road in Sussex County.
Georgetown Mayor Bill West told WMDT that the incident stemmed from two chemicals being mixed together at the facility.
"We've had somebody mix two chemicals together at the Perdue plant that has put off a smell," Mayor West explained.
Police lifted the order around 10:46 p.m., saying the incident was resolved and crews had cleared the scene.
No injuries have been reported.