Fire officials describe the blast as minor.

Firefighters responded to an explosion at a business on Jefferson Road in Henrietta.

It happened at the Schlegel Systems, a manufacturing company off Jefferson Road near Winton Road just before 10:30 a.m. Tuesday.

Fire officials describe the blast as minor, saying it was a natural gas explosion in a boiler tank.

A 58-year-old employee was looking through the "looking glass" of the boiler when too much pressure had built inside the boiler. This pressure knocked the man to the floor and caused head pain and ringing in his ears.

He was taken to the hospital for minor injuries.