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
Canada and the Kyoto Protocol of compliance has been estimated 20 times lower. States for which the emissions are not covered by the Kyoto Protocol (the US and China) have the largest emissions, being responsible for 41% of the Kyoto Protocol. China's emissions increased by over 200% from 1990 to 2009. Canadian Council of Chief Executives VP John Dillon argued (2011-11-22) that a further extension of Kyoto would not be effective as many countries, not just Canada, were not on track to meet their 1997 Kyoto commitments to reduce emissions. He called for a comprehensive, long-term global agreement that includes major emitters like the US,