###### Abstract  
Fluorinated greenhouse gases (F-gases) are used for various applications, such as in refrigeration and air conditioning, as substitutes of the ozone-depleting substances. Their utilization has increased drastically over the last few decades, with serious consequences for global warming. The Kigali Amendment to the Montreal Protocol and several national and international legislations, such as the 2014 EU F-gas Regulation, aim to control the utilization and emissions of these gases. In the EU, the phase-down of hydrofluorocarbons (HFCs) is underway, with successive reductions in quotas up to 2050. Under this scenario, efficient strategies for managing the produced and already existing F-gases are of vital importance to guarantee that their effect on the environment is mitigated. Up to now, most of the F-gases recovered from end-of-life equipment or when retrofitting systems are either released into the atmosphere or destroyed. However, in order to put forward a cost-efficient adaptation to the F-gas phase-down, increasing separation and recycling efforts must be made. This critical review aims at providing a revision of the current F-gas management problems and strategies and providing an overview on the innovative strategies that can be applied to contribute to build a sustainable market under circular economy principles. fluorinated greenhouse gases; gas separation; WEEE; refrigerant reclamation; refrigerant recycling; climate change; circular economy +
Footnote †: journal:  
(PFCs), sulfur hexafluoride (SF\({}_{6}\)), and nitrogen trifluoride (NF\({}_{3}\)), are the so-called fluorinated greenhouse gases (F-gases). These synthetic gases have several advantages over naturally occurring gases, such as durability, inertness, non-flammability, non-explosivity, non-reactivity, non-toxicity, and thermal stability [3]. While these properties are ideal for refrigeration and other industrial applications, these compounds are harmful to the environment. Most F-gases are highly stable in the atmosphere, with an atmospheric lifetime of up to 50,000 years, and are potent greenhouse gases (GHGs), with a global warming potential (GWP) up to 23,000 times greater than that of CO\({}_{2}\). Consequently, small atmospheric concentrations of F-gases induce large effects on global temperature and have a great impact on climate change. Upon releasing, F-gases persist in the atmosphere and their effects cannot be controlled, affecting the environment for long periods. Therefore, the substitution of F-gases by other compounds is essential to control their impacts in the environment. In 2015, F-gases represented 2% of the global GHG emissions [4], and in 2018 they were 3% of the GHG emissions in the EU [5]. Considering the high GWP of the F-gases, they have a major contribution to global warming. While the emissions of all other GHGs in the EU have decreased, the emissions of F-gases almost doubled from 1990 to 2014 [5] and were expected to have a 4 to 5-fold increase in 2005-2050 if efficient measures were not taken [6]. A key aspect of F-gases is that they are synthetic. Therefore, unlike natural pollutants, their production, use, and emissions can be almost totally controlled if appropriate and efficient legislations and practices are applied. The transition into alternatives with lower GWP is already underway and it is expected that it can be achieved almost totally in the near future. However, most of the F-gases produced in the last few decades are stored inside equipment or are part of several products. Therefore, the correct handling and management of these equipment and products, even after the complete transition of the new alternatives, is key to control the release of F-gases into the atmosphere. This critical review aims at giving a perspective of the legislation and mechanism to progress the F-gas phase-down and of the current F-gas management practices of waste electrical and electronic equipment (WEEE) and end-of-life vehicles (ELVs).