KNOXVILLE, Tenn. (AP) - Knoxville's Solid Waste Management Facility will remain closed Friday as crews work to dispose of toxic chemicals that were accidentally brought there.

Public Works Director David Brace tells local media that workers found PCBs - man-made chemicals once widely used in electronics - leaking from switch boxes and transformers in a pile of construction debris picked up by a crew Wednesday.

According to the Agency for Toxic Substances and Disease Registry, exposure to PCBs can cause acne and rashes in adults, neurobehavioral and immunological changes in children and cancer in animals.

The workers immediately shut down the facility, called in a contracted environmental engineering firm and began working to clean up the chemicals. Cleaning continued through Thursday.

Brace says officials are investigating where the waste came from.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.