Zeotropic mixture harmful effects that hydrochlorofluorocarbons (HCFC) and chlorofluorocarbons (CFC) have on the ozone layer and global warming. Researchers have focused on using new mixtures that have the same properties as past refrigerants to phase out harmful halogenated substances, in accordance to the Montreal Protocol and Kyoto Protocol. For example, researchers found that zeotropic mixture R-404A can replace R-12, a CFC, in household refrigerators. However, there are some technical difficulties for using zeotropic mixtures. This includes leakages, as well as the high temperature glide associated with substances of different boiling points, though the temperature glide can be matched to the temperature difference
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