According to reports by BBC News, residents reported hearing a loud bang and seeing a plume of smoke at the AMG Alpoco plant in Holyhead at about 18:00 BST on Saturday.
Two men made their own way to hospital for treatment for minor injuries, North Wales Fire and Rescue Service said.
AMG Alpoco has not yet been available to comment on the concerns.
Everyone at the plant was accounted for and four crews were sent to the scene, the fire service added.
Photo courtesy of BBC NEWS