Rescue crews on the scene at Stepan Chemical. (CBS))

Rescue crews on the scene at Stepan Chemical. (CBS))

CHICAGO (CBS) — Rescue crews are on the scene of a possible chemical leak at a plant in far southwest suburban Elwood.

The incident occurred around 9:30 a.m. on Tuesday at Stepan Chemical Co., 22500 W Millsdale Road.

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According to the Will County Emergency Management Agency, a relief valve opened up and a chemical called therminol was released in vapor form.

A total of 18 workers in the area were exposed and most used a decontamination shower to treat themselves. One person was taken to a hospital in Joliet.

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Several ambulances and hazardous materials personnel were sent to the scene.

According to the company website, Stepan Company was founded in 1932 by Alfred C. Stepan Jr.

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Headquartered in Northfield, Stepan manufactures basic and intermediate chemicals for a variety of food and pharmaceutical products.