O'FALLON, Mo. — Emergency crews responded to a hazmat situation in O'Fallon, Missouri.

At 7:45 a.m. Wednesday, firefighters responded to SAK Construction at 864 Hoff Road, which is just off of Interstate 70 in St. Charles County.

Some solid organic peroxide leaked. There were concerns because the product must be kept cool because it can generate its own heat. Crews had to work to keep the organic peroxide cool to stabilize it before they could address the leak.

About a dozen people were evacuated from the scene. The St. Charles County Ambulance District checked out those who were evacuated and also checked the first responders who are were in contact with the potentially contaminated area.

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No one was taken to the hospital.

There's no information at this time about what led to the leak.