Abstract: At 4:00 p.m. on March 13, 2017, in preparation of a new pump arriving, a coworker started draining lines leading to a 30,000 gallon liquid anhydrous ammonia tank. After the tank drained, the coworker started loosening the bolts that held the pump down; however, heard gas escaping and immediately stopped work. The coworker left the area, as well as the bolts in a loosened state. Later, the coworker was assigned to go get a truck while they waited for the tank to finish draining. Unaware of the potential gas leak, the employee returned from lunch and noticed the loosened bolts. So, the employee continued where the coworker had left off in removing the pump. As the employee used an impact wrench to finish removing the bolts, the pump came loose and released anhydrous ammonia. The caustic liquid contacted the employee's hands, arms, and chin, where he sustained chemical burns.