An ammonia leak (NH3) occurred around 10 pm on the refrigeration installations of a dairy. The 3 detectors placed in the vulnerable zones activated one after the other at their maximum threshold, triggering automatic shutoff and a security mode protocol for the dairy’s refrigerating units. The employees on duty left the premises to take shelter. The dairy’s managers and maintenance company were on the scene by 10:30 pm. Responders wearing appropriate gear surveyed the site in order to identify the source of the leak. Found on an aboveground “drain”, the leak could be isolated; the refrigeration installations resumed operations at 12:15 am. The alarm was lifted 5 min later, and the dairy employees returned to their posts.

Property damage was limited, with plant activities suspended for 6 hours; 1 tonne of NH3 was released into the atmosphere out of the 10 tonnes contained inside the facilities. No toxic concentration of NH3 was detected outside the site boundary.

A new leak of a similar type occurred on 15th February (ARIA 37167). The company’s Hygiene and Safety Committee met within the next few days, and an operational response programme was implemented. Some of the facilities were modified (hydraulic and NH3 circuits, electric control boxes); operations resumed at the dairy on 15th March.