The gradual phase-out of ODP and global warming refrigerants has been boosting promotion of the use of flammable, toxic and high-pressure alternatives but accident prevention and emergency preparedness are seen as key to the widespread introduction of these alternatives in developing economies.
These were the views of international experts at a recent UNEP meeting in Yerevan, Armenia.
In separate presentations, Alexander Cohr Pachai, technology manager at Johnson Controls Denmark and Gert Nielsen, of leading Scandinavian consulting engineers Multiconsult A/S, pointed out that accidents happen mainly because of lack of training, the poor design of refrigeration and air-conditioning systems, irresponsible company management or unprofessional behaviour of service technicians. Good practices and safety standards are often ignored and systems are retrofitted with flammable refrigerants which are not designed for that purpose.
Many accidents, it was said, are not related to the choice of the refrigerant, and they happen because of risky behaviour including falls from height because of unsafe working practices. Often fires originate from faulty electrical systems rather than the refrigerant circuits.
Explosions have occurred with refrigerants such as R22, R134a or R407C which are normally considered non-flammable. The reason is that at elevated pressure and temperature levels, the lower flammability limit can be reached if there is air in the system. Other accidents occurred because of counterfeit refrigerants containing methyl chloride which reacts with the aluminium in the compressor.
The audience was told that a common reason for fire in air conditioning systems is lack of proper maintenance and cleaning when dust is ignited by short circuits in the electrical components or damaged wires. Incidents might become accidents because of wrong reactions such as pulling out electrical plugs in case of refrigerant leaks in the machine room.
The machine room should only be accessible to qualified persons as specified in the standards, and not be used as a storage room or parking place for vehicles, they advised.
A key message from the presentations was that legislation, standards and codes of good practices should not be questioned on the basis of accidents that happened because people ignored them.
They also added a word of caution, that the media does not always tell the full story since important details concerning the causes of accidents are missing or unknown at the time of reporting.
Priority should be given to appropriate training, the enforcement of relevant legislation, standards and codes of good practices, the safe design of refrigeration and air conditioning systems as well as the promotion of a general safety culture. Safety should be part of the company policy from the top to the bottom and remain a management priority.