CONCORD, Mass. (AP) — Officials say road salt led to a hazardous materials scare that shut down a hospital emergency room in Concord for several hours.

Hospital officials say a patient walked into the ER at Emerson Hospital around 5 p.m. Saturday with medical complaints and an unidentified white powdery substance.

Hospital officials secured the area and diverted new patients to other facilities. At least five people were put through a decontamination process.

After hours of testing, the substance was identified as road salt, which can cause burning to the skin. The ER was reopened around 9 p.m.