A laboratory explosion Tuesday morning sparked a huge fire at a refinery in Yabucoa, Puerto Rico, specializing in recycled oils and lubricants.

At about 12:20 a.m., the explosion shook Olein Refinery & Lubricants, a company with a processing capacity of 10 million gallons of used oil per year, Primera Hora reports. Firefighters from Yabucoa, Juncos, Humacao, Caguas, Gurabo and San Lorenzo responded to the scene.

The fire was contained by 2:30 a.m., according to the Negociado del Cuerpo de Bomberos Facebook page.

A night shift was on duty at the time of the explosion and fire, but no injuries were reported. The cause of the initial explosion is under investigation.