Hydrofluoroalkanes (HFAs) are a class of compounds used primarily as propellants in metered-dose inhalers (MDIs) and as refrigerants.
They are composed of hydrogen, fluorine, and carbon atoms.
HFAs were developed as replacements for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) due to their lower potential for ozone depletion and reduced global warming potential.
The most commonly used HFAs in medical applications are 1,1,1,2-tetrafluoroethane (HFA-134a) and 1,1,1,2,3,3,3-heptafluoropropane (HFA-227), used for their chemical stability, non-flammability, and low toxicity, making them suitable for delivering medications via inhalation.
In addition to their use in MDIs, HFAs are employed in refrigeration, air conditioning, and as blowing agents in the production of foamed plastics.
Despite their advantages, HFAs are potent greenhouse gases, and efforts are ongoing to mitigate their environmental impact.