In preparation for the phaseout of HCFCs, the United Nations Environment Program has produced a series of fact sheets on the safe use of alternative refrigerants.
Produced by UNEP's OzonAction Division of Technology, the safety guide points out that the newer alternatives possess very different toxicity, flammability or higher pressure characteristics to R22.
Three separate factsheets cover the topics of toxicity, flammability and higher pressures.
"When refrigeration and airconditioning equipment is installed, serviced, repaired and dismantled, safety issues need to be carefully evaluated and considered particularly when servicing technicians have to deal with refrigerants with properties that are unfamiliar," the fac sheet explains.
"On the topic of flammability, the risk arises with the possible ignition of a flammable concentration. There are many flammable refrigerants and the extent of their flammability varies widely."
The flammability fact sheet covers tools and equipment, as well as special requirements.
When it comes to dealing with higher pressures, the fact sheet explains that there are several refrigerants with a higher pressure than R22, most of these are within a pressure range which is not more than 50 per cent greater.
"Carbon dioxide (R-744) has a substantially higher pressure, typically by a factor of six. For some others such as R-410A and HFC-32, the pressure is notably higher so paying attention to the pressure aspects remains important," according to the fact sheet.
Special requirements range from ensuring systems have a high level of leak tightness to the careful selection and application of additional pressure safety devices such as pressure limiting switches and pressure relief valves.
On the subject of higher toxicity refrigerants, including ammonia, the primary hazard is the inhalation of leaked refrigerant.
The fact sheet recommends designing the system and components for smaller refrigerant charge amounts, not installing equipment in vulnerable locations and more frequent use of gas detection and ventilation systems to assist with despersing any leaks.