FDA has proposed removing chlorofluorocarbons used as propellants in albuterol metered-dose inhalers from the essential-use exemptions listed under the global treaty to protect the ozone layer. Albuterol is used to treat bronchospasm associated with asthma and chronic obstructive pulmonary disease. The Montreal Protocol on Substances That Deplete the Ozone Layer obligates governments to phase out ozone-depleting substances but allows them to continue using a specified amount of a banned substance if it is considered essential. Previously, either trichlorofluoromethane (CFC-11) or dichlorodifluoromethane (CFC-12) was required as a propellant for albuterol inhalers. But now an alternative propellant, the hydrofluoroalkane HFA-134a (CF3CH2F), which does not deplete ozone, is available. One of the most important essential uses of chlorofluorocarbons has been in metered-dose inhalers. FDA is accepting public comment on the proposal until Aug. 16 [Fed. Regist., 69, 33602 (2004)].