are based on the leaks occurring in insufficiently leak-tight refrigerating installations or during maintenance-related refrigerant-handling processes. Depending on the refrigerants used, these installations and their subsequent leaks can lead to ozone depletion (chlorinated refrigerants like CFCs and HCFCs) and/or climate change, by exerting an additional greenhouse effect (fluorinated refrigerants: CFCs, HCFCs and HFCs). Alternative Refrigerants In their continuous research of methods to replace ozone-depleting refrigerants and greenhouse refrigerants (CFCs, HCFCs and HFCs, respectively) the scientific community together with the refrigerant industry came up with alternative all-natural refrigerants which are eco-friendly. According to a report issued by the UN Environment Programme, “the increase in HFC emissions is projected to offset much of the climate benefit achieved by the earlier reduction in the emissions of Ozone depleting substances”. Among non-HFC refrigerants found to successfully replace the traditional ones are ammonia, hydrocarbons and carbon dioxide. Ammonia The history of refrigeration began with the use of ammonia. After more than 120 years, this substance is still the preeminent refrigerant used by household, commercial and industrial refrigeration systems. The major problem with ammonia is its toxicity at relatively low concentrations. On the other hand, ammonia has zero impact on the ozone layer and very low global warming effects. While deaths caused by ammonia exposure are extremely rare, the scientific community has come up with safer and technologically solid mechanisms of preventing ammonia leakage in modern refrigerating equipment. This problem out of the way, ammonia is considered an eco-friendly refrigerant with numerous applications. Carbon Dioxide (CO2) Carbon dioxide has been used as a refrigerant for many years. Just like ammonia, it has fallen in almost complete disuse due to its low critical point and its high operating pressure. Carbon dioxide has zero impact on the ozone layer and the global warming effects of the quantities required for use as a refrigerant are also negligible. Modern technology is solving such issues and is widely used today as an alternative to traditional refrigeration in several fields: industrial refrigeration ( is usually combined with ammonia, either in cascade systems or as a volatile brine), the food industry (food and retail refrigeration), heating (heat pumps) and the transportation industry (transport refrigeration). Hydrocarbons Hydrocarbons are natural products with high thermodynamic properties, zero ozone-layer impact and negligible global warming effects. One issue with hydrocarbons is that they are highly flammable, restricting their use to specific applications in the refrigeration industry. In 2011,