Ammonia safety & handling
Ammonia has been used as a heat transfer fluid since the dawn of refrigeration. James Harrison’s original refrigeration machines usedammonia, and to this day it’s still used widely in our cold stores,refrigeration facilities, and even in some air conditioning systems.
Ammonia is also toxic, however, and it can be very dangerous if nothandled correctly.
Three things to remember:
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Safe handling of ammonia is based on knowledge. The vast majority of ammonia accidents can be traced back to mistakes made by operators or service people, or sometimes even the system designer.
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Water should never be sprayed onto ammonia. Spraying water directly onto ammonia will force it to evaporate quicker and produce large quantities of heat, risking an explosion.
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Ammonia is a colourless gas, however, it has a very strong odour. This odour can be as good a warning of a refrigerant leak as a dedicated leak detector, so be aware of it.
What provisions should be made inside the refrigerated space?
Refrigerated spaces have to incorporate a number of safety features, including; access doors that can be opened from inside and outside, a means to manually open doors that are operated electrically or pneumatically, an electric light which can’t be turned off from outside the room, independent lighting indicating the emergency exit or alarm button, an alarm light or buzzer operated from within the space and visible or audible outside the space, and either an axe near the door, a telephone in every room, an unlocked insulated safety exit which can only be opened from the inside, or a panel removable from the door or adjacent wall making an opening that a person can pass through easily. If your plant doesn’t have all of these safety features, speak to your supervisor. If you are the supervisor, take immediate steps to rectify the situation (see AS/NZS 1677.2-1998 for more detail).
Source: Article courtesy of HVAC&R Nation August 2007, Victorian Code of Practice for Ammonia Refrigeration
