Employee #1 attempted to replace a leaking oil valve on a minus 30 degree freezer when a tank inside the freezer exploded. The company uses anhydrous ammonia to manufacture ice cream. The liquid ice cream mixture (at 50 degrees) is added to the tank. This freezer was down for seven days, and the tank’s oil had congealed. Normal weekly maintenance requires the removal of used oil through the oil valve. Employee #1 closed all valve lines and used steam to loosen the thick oil. The steam caused pressure to build up inside the tank, and the tank, not equipped with a relief valve, exploded.
When the tank exploded, Employee #1 was killed.
Employee #2 was approximately 10 feet away and was hospitalized with burns to his eyes.
Employee #3 was injured in an adjacent room when he inhaled the ammonia vapors.