La Salle residents told to avoid contact with green residue released during fire at chemical plant

La Salle residents are being told to avoid contact with a green residue that was released during a fire at a chemical plant Wednesday in the town about 90 miles southwest of Chicago.

The substance is from potassium permanganate, a chemical compound produced at the Carus Chemical plant and used to treat drinking water, wastewater and industrial chemicals, officials said.

“Do not touch this substance,” La Salle police warned in an alert to residents. “If you see this substance near or on your residence, it can be deactivated.”

It advised residents to use a mixture of one gallon of water, one gallon of peroxide and one gallon of vinegar to clean the residue.

Despite the warning, a spokesperson from the chemical plant said the compound was not toxic.

“It’s a good chemical that cleans up the drinking water,” Allen Gibbs, the company’s vice president of operations, said at a news conference Wednesday afternoon. “When it’s in the form it’s in, it can create a problem. It oxidizes and it turns into a dust.”

Robert Kondreck, an on-scene coordinator for the U.S. Environmental Protection Agency, said a team began monitoring air in the area upwind of the plant on Wednesday afternoon.

Kondreck said representatives for the U.S. Coast Guard and the Illinois Environmental Protection Agency also visited the site and believe the nearby Vermilion River did not receive runoff from the firefighting efforts.

The city had issued a shelter in place order after the fire broke out in the shipping area of the plant in the 1500 block of 8th Street around 9 a.m. The order was lifted about 5 p.m.

The blaze sent dramatic columns of smoke into the sky. Aerial photos of the site showed a collapsed structure, burned columns, trucks and other rubble.

La Salle Fire Chief Jerry Janick said a possible explosion may have led to the blaze, but the cause of the fire remains under investigation.

A firefighter suffered minor injuries and was treated and released, officials said. No other injuries have been reported, and all workers at the plant have been accounted for, officials said.

Residents with questions can call Carus Chemical at (815) 224-6206.

The Associated Press contributed