Monday Accident & Lesson Learned: Overpressure of Explosion Proof Enclosure
This past May, as an engineer unscrewed the cover off of an explosion-proof enclosure, a mass amount of pressure inside forced the cover to propel towards the engineer giving him a fatal head injury. Two problems were found: the pressure was caused by leaked sample gas or instrument air components and there is no outer pressure meter to read before attempting to open.
(Resource: IOGP Safety Alert #288)