An employee went to perform a routine visual inspection by opening the manway hatch of the tank. As he turned to the tank and opened the manway hatch, the steam and/or the caustic cleaning solution was released with a high force. The temperature of the tank holding the caustic solution was 200 F. The employee sustained chemical and thermal burns to his back and body. He also suffered a compound fracture to his right ankle and fractures to his right elbow and right scapula. The employee was hospitalized.