Thick black smoke billowed over the city, near the site of the former Nazi German death camp of Auschwitz, local media reported.
The fire broke out before noon inside one of the plant's facilities, which produces latexes, synthetic rubbers and styrene plastics.
A spokesman for the regional fire service, Hubert Ciepły, said that one person was injured and taken to a hospital before the firefighters arrived.
About 50 firefighters were deployed to contain the flames.
Police are investigating the cause of the fire.
(mp/gs)
Source: IAR, PAP