In an industrial catering facility dedicated to fish dishes employing 700 staff, a water pipe carrying an added bio-detergent product with corrosive properties was punctured and its contents spilled onto a 28-mm diameter copper pipe transporting chlorodifluoromethane (R22) under high pressure. This second pipe, exposed to the action of a corrosive liquid for several months, in turn was also perforated. Approx. 120 kg of liquid refrigerant leaked for 2 to 3 consecutive hours. The cloud formed was heavier than air and got suctioned to the ground and propelled to another part of the building, where it reached the gas burners of an industrial frying machine. When making contact with the flame, the R22 refrigerant decomposed into irritant and toxic products, such as phosgene and hydrochloric and hydrofluoric acids; 13 employees became intoxicated.
The investigation conducted by British authorities (HSE) revealed several flaws in company procedures regarding air conditioning system maintenance (by failing to specify controls, responsibilities, a preventive maintenance programme, personnel training, and a leak detection system). The company was fined 15,000 GBP for noncompliance with the labour regulation and another 4,000 GBP for noncompliance with ozone legislation.
The company performed many improvements in managing its refrigeration and air conditioning systems. All systems were disassembled; the defective parts and sections were either replaced or repaired. The cost of this remedial campaign was appraised at 20,000 GBP. A preventive maintenance programme was also instituted. A new software was installed and run in order to record the operating times of each refrigeration or air conditioning system component. This programme automatically indicated the devices requiring inspection or replacement. One of the company’s engineers underwent training in refrigeration engineering, with assistance provided by a staff member from a specialised firm in developing an in-house guide. All actions taken by the external specialist were recorded in the computer programme. Moreover, a new leak detection method using fluorescent tubes was implemented.
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