LEHI — A small explosion in a dental lab Monday sent one man to the hospital with minor injuries and injured a woman.

Just before noon, a 75-year-old man was working at Alpine Dental Lab, 1220 N. 500 West in Lehi, when a small explosion injured his hand.

The man was taken via ambulance to Intermountain Medical Center, and the woman was treated at the scene for minor injuries, said Lehi Police Lt. Darren Paul.

Officials still aren't sure what caused the explosion, although they know it was contained to one small room and did not start a fire or send out smoke or noxious gases.

However, there were little pieces of debris on the walls and ceiling, Paul said.

"When the medical and fire people got on scene, they evacuated the building and cleared it to make sure that it was structurally safe," Paul said. "There was no other threat of an explosion and they have released the building for occupancy. However, the investigation is ongoing."

Lehi's fire marshal and police department plus the Occupational Safety and Health Administration will be reviewing the case to see if there were any safety violations, Paul said.

There are no patients treated at the lab, Paul said, as it's a place that specializes in the production of crowns and dentures.