### Human:\nwhat's the major difference between cfc and hfa inhalers for asthma?\n\n### Assistant: cost. cfc inhalers run about $5 to $25 apiece whereas the hfa inhalers cost $30 to $60. the hfa inhalers that have been available for several years are brand-name and it could be five years before patents expire allowing less expensive generics to enter the market.