Thousands of people were told to stay home with their windows shut Monday after a fire at a Georgia industrial plant caused a chemical reaction that prompted around 17,000 people to evacuate Sunday and left potentially harmful chlorine lingering in the air.

Rockdale County officials ordered people to evacuate the area near the BioLab plant in Conyers, Ga., and they said others should stay home to avoid the “harmful irritant chlorine.”

For everyone sheltering in place, the best practice is to turn the air conditioning off and keep windows and doors shut,” a statement said.