Most ammonia refrigeration personnel know their refrigerant is flammable, but most would also tell us that they do not have any "Hazardous Locations" (e.g. Class 1, Div 1 or 2 locations).  Most of these workers will explain their ventilation system is designed, installed, and maintained to ensure that NH3 never achieves 25% of it's LEL (e.g. 40,000 ppm), thus allowing the facility to escape the requirement of making their engine room an electrically classified area (e.g. hazardous location).  But in these technological days, this may no longer be the case...

An older post, with updates...Ever since the 2005 BP Texas City tragedy, refineries and chemical plants have been working diligently to review “facility siting” risks for their facilities.  As with all of the PSM elements, many of us took this new focus as a learning opportunity.  We had all done something we called “facility siting” in our Process Hazards Analysis, but in the early 1990’s many of us “did not know what we did not know” in regards to what a real facility siting analysis was suppose to look like. 

Let me be clear... I am not a Fall Protection expert in any stretch of the imagination, so I am all about engineering out the fall hazards whenever possible.  A few weeks ago we received a call from a new client who had just suffered a bad accident where one of their star employees was on the roof working on a piece of equipment.  The roof is perfectly flat and has a raised edge of 27" around it.  The employee was working on an environmental control device and as he was trying to pull some duct work up from the roof penetration, he began to step back in order to get the duct work up and out of the roof hole - something he had done dozens of times in the past couple of years.  Unfortunately, this time he did it with his back to the edge and as he stepped back with this heavy piece of duct work that was hung up in the penetration, it broke free and he and the duct work took a 30' fall over the edge.  He survived merely because he flip in the air and landed on the fiberglass duct work which acted as a cushion.  A fractured sternum and several broken ribs and he was back to work four days later on light duty.  The results could have EASILY been a fatality; he knows it and the company knows.