Abstract: While cleaning a fermenting tank that was approximately 10 ft tall with a round porthole opening at the top, Employee #1 put water in the tank (about half full) and started the heater. He put sodium hydroxide powder at the bottom of a bucket, and added water to within 2 to 3 in. of the top. After the water in the tank became hot, Employee #1 climbed the ladder to the platform near the top of the tank and started to add the sodium hydroxide to the tank. When the cleaning solution hit the water, steam erupted from the tank, startling the employee and causing him to spill the concentrated solution onto his hand, arm, and body. He was not wearing gloves even though they were provided. Employee #1 removed his contaminated clothing, and attempted to neutralize the base with a mild acid. A coworker stopped the neutralization and drenched Employee #1 with water. Employee #1 sustained chemical burns on his hand, wrist, arm, and shoulder.