Hydrofluorocarbons, chlorofluorocarbon

Production of hydrogen fluoride from reaction of Cap2 with sulfuric acid is the largest user of fluorspar and accounts for approximately 60—65% of total U.S. consumption. The principal uses of hydrogen fluoride are ia the manufacture of aluminum fluoride and synthetic cryoHte for the Hall aluminum process and fluoropolymers and chlorofluorocarbons that are used as refrigerants, solvents, aerosols (qv), and ia plastics. Because of the concern that chlorofluorocarbons cause upper atmosphere ozone depletion, these compounds are being replaced by hydrochlorofluorocarbons and hydrofluorocarbons. 

A leader in the refrigerants industry, we manufacture and supply customers with economical chlorofluorocarbon (CFC) replacements and non-ozone depleting hydrofluorocarbon (HFC) refrigerants for automotive, home, commercial and transportation uses. In the Americas and Asia, you can find these products under the Genetron name and in Europe and the Middle East under Honeywell Refrigerants. 

As you know, most countries are phasing out certain refrigerants to lessen damage to the ozone layer. The chemicals being phased out are chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). Replacements are hydrofluorocarbons (HFCs) and certain blends. The DuPont web site (www.dupont.com) gives the handy Table I of recommended replacement refrigerants for various applications. 

The cap is the percentage of the calculated level of chlorofluorocarbons consumed in the base year plus the calculated level of hydrofluorocarbons consumed the same base year It applies only to HCFCs Calculated in the context means that the amount of each substance is adjusted by its ozone depletion potential (ODP), a measure of its potential to deplete stratosphenc ozone relative to that of CFC 11... 

Refngeration technology is moving into a new phase with the introduction of hydrofluorocarbons that combme the safety of chlorofluorocarbons with a much lower environmental impact The considerable care bemg taken to choose the new refngerants under the close scrutmy of the public and regulatory bodies will ensure that the new products wiU benefit mankind for years to come... 

Acronyms for chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (MFCs)... 

Hydrofluorocarbon-134a or 1,1,1,2-Tetrafluoroethane (HFC-134a) has been developed as a replacement for fully halogenated chlorofluorocarbons because, compared with chlorofluorocarbons, its residence time in the atmo... 

In the discussion of ecotoxicity the perhalogenated chlorofluorocarbons (CFCs), hydrogen-containing hydrochlorofluorocarbons (HCFCs) and the chlorine-free hydrofluorocarbons (HCFs) have been for several years in the headlines (the depletion of the ozone layer in the stratosphere, the greenhouse or global warming effects in the troposphere).75... 

Within the family of halocarbon refrigerants are compounds that contain chlorine, fluorine, and carbon, the chlorofluorocarbons (CFCs). Hydrochlorofluorocarbons (HFCs) contain chlorine, fluorine, carbon and hydrogen. Halocarbons that contain only carbon, fluorine, and hydrogen are called hydrofluorocarbons (HFCs). 

The active ingredients in MDIs are usually water-soluble and chlorofluorocarbon- or hydrofluorocarbon-insoluble. Some CFC and HFA formulations use ethanol as a suspending agent by using an ethanol-insoluble salt form of the drug. Since the vehicle in MDIs must be propellant-based, a product with the drug suspended in the propellant may be the most stable dosage form. 

In the early 1990s, chlorofluorocarbon refrigerants and propellants were largely replaced by hydrofluorocarbons and hydrochlorofluorocarbons in order to reduce stratospheric ozone depletion. The hydrochlorofluorocarbons and hydrofluorocarbons, unlike the older chlorofluorocarbons, are unstable in the... 

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