January Safety Moment: Ammonia Refrigeration

Ammonia is considered a high health hazard because it is corrosive to the skin, eyes, and lungs with exposure to 300 parts per million (ppm) being immediately dangerous to life and health.  Ammonia is also flammable at concentrations of approximately 15% to 28% by volume in air and when mixed with lubricating oils, its flammable concentration range is increased.  It can explode if released in an enclosed space with a source of ignition present, or if a vessel containing anhydrous ammonia is exposed to fire.  Fortunately, ammonia has a low odor threshold (20 ppm), so most people will seek relief at much lower concentrations.

The use of anhydrous ammonia is common as a refrigerant in many industrial facilities, including:

  • Meat, poultry, and fish processing facilities
  • Dairy and ice cream plants
  • Wineries and breweries
  • Fruit juice, vegetable juice, and soft drink processing facilities
  • Cold storage warehouses
  • Other food processing facilities
  • Petrochemical facilities

Ammonia spills and releases pose a significant threat to workers from skin contact, inhalation, and fire and explosion.  The key provision of process safety management is Process Hazard Analysis (PHA) – a careful review of what could go wrong and what safeguards must be implemented to prevent releases of hazardous chemicals such a ammonia.  PSRG have highly skilled Facilitators who can guide your team through the PHA process, so if you would like to know more please contact us at psrghouston@psrg.com.

Source: https://www.osha.gov/SLTC/ammoniarefrigeration