Metered-dose inhaler stringent set of criteria, they must: In the early days of MDIs the most commonly used propellants were the chlorofluorocarbons CFC-11, CFC-12 and CFC-114. In 2008 the Food and Drug Administration announced that inhalers using chlorofluorocarbons as a propellant, such as Primatene Mist, could no longer be manufactured or sold as of 2012. This followed from the U.S. decision to agree to the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. Phospholipids are important natural surfactant lipids used in enhancing penetration and bioavailability. Phospholipids act by reducing the high surface tension forces at the air-water interface within the
Toxic Substances Control Act of 1976 later explained during a 1975 Congressional Testimony, "While some authority exists to control the production of certain categories of toxic substances, such as pesticides, drugs, and food additives, most existing Federal authorities are designed to prevent harmful exposure only after the substances have been introduced into production." In Order to adequately regulate what chemicals should enter the environment, CEQ recommended that the government create a more comprehensive chemical policy to identify and control the chemicals that are manufactured, produced, and used in the U.S economy. Specifically, CEQ recommended that TSCA strengthen government oversight by requiring the following measures: First, manufacturers