The transition to the new inhalers was mandated by Congress to remove one of the last remaining exemptions to the Montreal Protocol, a treaty signed in 1987 to reduce chlorofluorocarbon, or CFC, emissions that can damage the Earth’s ozone layer. The Food and Drug Administration was charged with phasing out all medications using CFC propellants once viable alternatives became available. Albuterol inhalers, used as rescue medicines for asthma attacks, were some of the last holdouts.