GLENWOOD SPRINGS, Colo. - Food contaminated with a chemical at a Colorado restaurant sent four people to a hospital. 

Hospital officials say the female customers of the Qdoba Mexican Grill in Glenwood Springs were treated and released Thursday. 

Qdoba franchise owner Michael Scott says employee error caused a chemical to get into a food product. 

Scott did not specify the chemical but says the contamination happened during a shift change. 

The restaurant closed immediately and patrons were told to go the hospital.

Health officials say two people sought treatment at Valley View Hospital after eating white rice and two seeking medical care did not experience symptoms or eat white rice. 

The restaurant reopened Friday.

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