Abstract: On August 20, 1999, Employee #1 was performing maintenance on the float column of a slop tank sub-unit in the refrigeration engine room. The objective of the maintenance was to change the sight glasses on the float column. While removing a valve seal cap, the valve body loosened and allowed approximately 61 pounds of ammonia to escape. Employee #1 and three employees of another company were exposed. Employee #1 was not wearing eye protection at the time of the incident and received an ocular exposure to the ammonia gas. The other three employees were sorting bell peppers approximately 100 yards south of the engine room at the time of the release. The three other employees reported eye and throat irritation. All four employees were treated and released at local hospitals. None are known to have sustained permanent injuries.