 There have been reports of refrigerators exploding if the refrigerant leaks isobutane in the presence of a spark.If the coolant leaks into the fridge, at times when the door is not being opened (such as overnight) the concentration of coolant in the air within the fridge can build up to form an explosive mixture that can be ignited either by a spark from the thermostat or when the light comes on as the door is opened, resulting in documented cases of serious property damage and injury or even death from the resulting explosion.Disposal of discarded refrigerators is regulated, often mandating the removal of doors for safety reasons.