A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, blowing agents, cleaning fluids, solvents, and as fire extinguishing agents. They have been shown to cause stratospheric ozone depletion and have been banned for many uses.
A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.
Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A group of ethane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.
The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).
A shift in the balance between production and destruction of STRATOSPHERIC OZONE that results in a decline of the amount of OZONE in the lower stratosphere.
Ozone in the Earth's stratosphere. It is produced continuously by the action of solar ULTRAVIOLET RAYS on oxygen in the stratosphere. The stratospheric ozone (especially at the ozone layer) blocks much of the solar UV radiation of wavelengths of 320 nanometers or less from being transmitted to lower ATMOSPHERE of the Earth.
The reactions and interactions of atoms and molecules, the changes in their structure and composition, and associated energy changes.
A hydrocarbon used as an industrial solvent. It has been used as an aerosal propellent, as a refrigerant and as a local anesthetic. (From Martindale, The Extra Pharmacopoeia, 31st ed, p1403)
The maintenance of certain aspects of the environment within a defined space to facilitate the function of that space; aspects controlled include air temperature and motion, radiant heat level, moisture, and concentration of pollutants such as dust, microorganisms, and gases. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The mechanical process of cooling.
A series of hydrocarbons containing BROMINE; CHLORINE and FLOURINE.
The science of controlling or modifying those conditions, influences, or forces surrounding man which relate to promoting, establishing, and maintaining health.
An agency of the NATIONAL INSTITUTES OF HEALTH concerned with overall planning, promoting, and administering programs pertaining to advancement of medical and related sciences. Major activities of this institute include the collection, dissemination, and exchange of information important to the progress of medicine and health, research in medical informatics and support for medical library development.
A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.
Inorganic compounds that contain chlorine as an integral part of the molecule.
Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)
A group of symptoms that are two- to three-fold more common in those who work in large, energy-efficient buildings, associated with an increased frequency of headaches, lethargy, and dry skin. Clinical manifestations include hypersensitivity pneumonitis (ALVEOLITIS, EXTRINSIC ALLERGIC); allergic rhinitis (RHINITIS, ALLERGIC, PERENNIAL); ASTHMA; infections, skin eruptions, and mucous membrane irritation syndromes. Current usage tends to be less restrictive with regard to the type of building and delineation of complaints. (From Segen, Dictionary of Modern Medicine, 1992)
Reproduction of data in a new location or other destination, leaving the source data unchanged, although the physical form of the result may differ from that of the source.
Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Supplying a building or house, their rooms and corridors, with fresh air. The controlling of the environment thus may be in public or domestic sites and in medical or non-medical locales. (From Dorland, 28th ed)
The contamination of indoor air.
An institute of the CENTERS FOR DISEASE CONTROL AND PREVENTION which is responsible for assuring safe and healthful working conditions and for developing standards of safety and health. Research activities are carried out pertinent to these goals.
A nonmetallic, diatomic gas that is a trace element and member of the halogen family. It is used in dentistry as flouride (FLUORIDES) to prevent dental caries.
Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
The study of chance processes or the relative frequency characterizing a chance process.
The condition in which reasonable knowledge regarding risks, benefits, or the future is not available.
The branch of mathematics dealing with the purely logical properties of probability. Its theorems underlie most statistical methods. (Last, A Dictionary of Epidemiology, 2d ed)
A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.
The complete summaries of the frequencies of the values or categories of a measurement made on a group of items, a population, or other collection of data. The distribution tells either how many or what proportion of the group was found to have each value (or each range of values) out of all the possible values that the quantitative measure can have.

Structural consequences of anesthetic and nonimmobilizer interaction with gramicidin A channels. (1/62)

Although interactions of general anesthetics with soluble proteins have been studied, the specific interactions with membrane bound-proteins that characterize general anesthesia are largely unknown. The structural modulations of anesthetic interactions with synaptic ion channels have not been elucidated. Using gramicidin A as a simplified model for transmembrane ion channels, we have recently demonstrated that a pair of structurally similar volatile anesthetic and nonimmobilizer, 1-chloro-1,2,2-trifluorocyclobutane (F3) and 1,2-dichlorohexafluorocyclobutane (F6), respectively, have distinctly different effects on the channel function. Using high-resolution NMR structural analysis, we show here that neither F3 nor F6 at pharmacologically relevant concentrations can significantly affect the secondary structure of the gramicidin A channel. Although both the anesthetic F3 and the nonimmobilizer F6 can perturb residues at the middle section of the channel deep inside the hydrophobic region in the sodium dodecyl sulfate micelles, only F3, but not F6, can significantly alter the chemical shifts of the tryptophan indole N-H protons near the channel entrances. The results are consistent with the notion that anesthetics cause functional change of the channel by interacting with the amphipathic domains at the peptide-lipid-water interface.  (+info)

Distinctly different interactions of anesthetic and nonimmobilizer with transmembrane channel peptides. (2/62)

Although it plays no clinical role in general anesthesia, gramicidin A, a transmembrane channel peptide, provides an excellent model for studying the specific interaction between volatile anesthetics and membrane proteins at the molecular level. We show here that a pair of structurally similar volatile anesthetic and nonimmobilizer (nonanesthetic), 1-chloro-1,2,2-trifluorocyclobutane (F3) and 1, 2-dichlorohexafluorocyclobutane (F6), respectively, interacts differently with the transmembrane peptide. With 400 microM gramicidin A in a vesicle suspension of 60 mM phosphatidylcholine-phosphatidylglycerol (PC/PG), the intermolecular cross-relaxation rate constants between (19)F of F3 and (1)H in the chemical shift regions for the indole and backbone amide protons were 0.0106 +/- 0.0007 (n = 12) and 0.0105 +/- 0.0014 (n = 8) s(-1), respectively. No cross-relaxation was measurable between (19)F of F6 and protons in these regions. Sodium transport study showed that with 75 microM gramicidin A in a vesicle suspension of 66 mM PC/PG, F3 increased the (23)Na apparent efflux rate constant from 149.7 +/- 7.2 of control (n = 3) to 191.7 +/- 12.2 s(-1) (n = 3), and the apparent influx rate constant from 182.1 +/- 15.4 to 222.8 +/- 21.7 s(-1) (n = 3). In contrast, F6 had no effects on either influx or efflux rate. It is concluded that the ability of general anesthetics to interact with amphipathic residues near the peptide-lipid-water interface and the inability of nonimmobilizer to do the same may represent some characteristics of anesthetic-protein interaction that are of importance to general anesthesia.  (+info)

Challenges in changing to non-chlorofluorocarbon inhalers in the treatment of asthma. (3/62)

The chlorofluorocarbon (CFC)-based metered dose inhaler, which has been the mainstay of the management of obstructive lung diseases, will soon be phased out world wide and replaced by CFC-free devices. Patients will have to be changed to the devices in a co-ordinated manner to avoid any risk to their health and safety. The different shapes and aerosol delivery characteristics of the new inhalers, as well as their distinctive taste, could add to the levels of poor drug use already experienced in asthma. From previous change scenarios in disease management, the potential for unstable asthma control is a real possibility with all the attendant costs. By using the time available before CFC-based inhalers are withdrawn, there is an opportunity to enhance asthma management during this period of change.  (+info)

Review of therapeutically equivalent alternatives to short acting beta(2) adrenoceptor agonists delivered via chlorofluorocarbon-containing inhalers. (4/62)

BACKGROUND: To study the transition from metered dose inhalers using chlorofluorocarbons as propellants (CFC-MDIs) to non-CFC containing devices, a systematic review was conducted of clinical trials which compared the delivery of salbutamol and terbutaline via CFC-MDIs and non-CFC devices. METHODS: Papers were selected by searching electronic databases (Medline, Cochrane, and BIDS) and further information and studies were sought from pharmaceutical companies. The studies were assessed for their methodological quality. RESULTS: Fifty three relevant trials were identified. Most were scientifically flawed in terms of study design, comparison of inappropriate doses, and insufficient power for the determination of therapeutic equivalence. Differences between inhaler devices were categorised according to efficacy and potency. Most trials claimed to show therapeutic equivalence, usually for the same doses from the different devices. Two commercially available salbutamol metered dose inhalers using a novel hydrofluorocarbon HFC-134a as propellant were equally as potent and efficacious as conventional CFC-MDIs, as were the Rotahaler and Clickhaler dry powder inhalers (DPIs). Evidence suggests that a dose of 200 microg salbutamol via CFC-MDI may be substituted with 200 microg and 400 microg of salbutamol via Accuhaler and Diskhaler DPIs, respectively. Terbutaline delivered via a Turbohaler DPI is equally as potent and efficacious as terbutaline delivered via a conventional CFC-MDI. CONCLUSIONS: When substituting non-CFC containing inhalers for CFC-MDIs, attention must be given to differences in inhaler characteristics which may result in variations in pulmonary function.  (+info)

Pharmacokinetics of chlorofluorocarbon and hydrofluoroalkane metered-dose inhaler formulations of beclomethasone dipropionate. (5/62)

AIMS: To compare the pharmacokinetic profile of Beclazone (beclomethasone dipropionate) in its chlorofluorocarbon (CFC)-based and CFC-free formulations. METHODS: Ten healthy adults received a single 1,000 microg nominal dose (ex-valve) of beclomethasone dipropionate from a CFC inhaler (BEC-CFC) or from a CFC-free inhaler containing hydrofluoroalkane (HFA)-134a (BEC-HFA) in an open-label, randomized, two-way, crossover study. Blood samples were collected predose and over 12 h after inhalation. Comparisons were made of maximum plasma concentration of beclomethasone 17-monopropionate (17-BMP) (Cmax), and area under the plasma concentration vs time curve (AUC). RESULTS: The tmax was significantly (P<0.05) earlier with BEC-HFA and plasma levels were significantly higher following administration of BEC-HFA than BEC-CFC. Geometric mean values for AUC were 1.5 fold greater (90% CI 1.3-1.9) and for Cmax were 1.9 fold greater (90% CI 1.6-2.6) following BEC-HFA than BEC-CFC. CONCLUSIONS: Our data in healthy volunteers would not be consistent with the manufacturers' recommendation for a microgram equivalent (1:1) nominal dose switch between these HFA and CFC formulations. Further well designed trials are required in asthmatic patients to properly define their respective dose-response relationships for antiasthmatic and systemic adverse effects.  (+info)

Global warming in the twenty-first century: an alternative scenario. (6/62)

A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO(2) greenhouse gases (GHGs), such as chlorofluorocarbons, CH(4), and N(2)O, not by the products of fossil fuel burning, CO(2) and aerosols, the positive and negative climate forcings of which are partially offsetting. The growth rate of non-CO(2) GHGs has declined in the past decade. If sources of CH(4) and O(3) precursors were reduced in the future, the change in climate forcing by non-CO(2) GHGs in the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO(2) emissions, this reduction of non-CO(2) GHGs could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition-specific long-term global monitoring of aerosol properties.  (+info)

Factors affecting the efficiency of aerosol therapy with pressurised metered-dose inhalers through plastic spacers. (7/62)

AIM: The main objective of this study was to compare the in vitro delivery of salbutamol from a chlorofluorocarbon(CFC)-propelled pressurised metered-dose inhaler (pMDI) versus a newly developed hydrofluoroalkane(HFA)-propelled pMDI through various spacers. In addition, we aimed to study the effect on bronchodilator response when using an optimal pMDI/spacer combination for aerosol delivery compared to a suboptimal combination. METHODS: Particle size distribution and output from salbutamol pMDIs containing either CFC propellants (Ventolin) or HFA propellants (Airomir) were measured using a multistage liquid impinger (MSLI) and compared to that through both detergent-coated (non-static) or untreated (static) large volume (Nebuhaler, Volumatic) and small volume (Aerochamber) plastic spacers. Flow-volume curves (FEV1) were obtained from twelve asthmatic children with known significant bronchodilator response (8 males), aged 13-17 years, randomly inhaling salbutamol from a CFC-pMDI through a static spacer (Nebuhaler) and from an HFA-pMDI through a non-static spacer (Nebuhaler). RESULTS: In vitro output of particles in the respirable range (< 6.8 microns) from HFA-pMDIs was significantly higher than that from CFC-pMDIs using various spacers. Removal of electrostatic charge increased output from CFC- and HFA-pMDIs through all spacers by 17-82%. The mean (SD) bronchodilator response after inhalation of salbutamol from a CFC-pMDI through a static spacer was 7.1% (6.3%) compared to 17.5% (7.9%) after inhalation from an HFA-pMDI through a non-static spacer (p = 0.002). CONCLUSIONS: Use of a newly developed HFA-propelled pMDI greatly improves drug delivery through spacers compared to a CFC-propelled pMDI. However, electrostatic charge in plastic spacers remains the key determinant limiting delivery of salbutamol from a pMDI through spacers, and can be reduced by soaking the spacer in a household detergent. Using an optimal pMDI/spacer combination leads to a significantly improved bronchodilator response.  (+info)

Moving from CFC aerosol to HFA aerosol or dry powder inhalers: what do patients think? (8/62)

BACKGROUND/OBJECTIVES: Environmentally friendly hydrofluoroalkane (HFA) pressurised metered-dose inhalers are currently being marketed to replace chlorofluorocarbon (CFC)-driven devices. It is uncertain whether these new formulations with different properties are acceptable to patients. Similarly, switching a patient to a dry powder inhaler (DPI) carries the risk of non-acceptance. METHODS: One hundred patients with obstructive airway disease on regular CFC aerosol inhaler medication underwent a standardised, structured interview. During the interview patients were asked to use a new HFA aerosol inhaler and three DPIs in random order. Patients' notions were recorded. RESULTS: Most patients (96) agreed to change from their CFC to the HFA inhaler, of those, only 12 did so with some reservation. Properties (taste, user-friendliness, design) of the HFA inhaler were rated favourably. DPIs represented an acceptable alternative to aerosol inhalers. In fact, 57 patients preferred a DPI over the HFA inhaler. Not all powder devices were equally acceptable. Replacing the CFC inhaler with patients' preferred alternative devices resulted in a more than 3-fold increase in costs. CONCLUSION: Concerns about the acceptability of reformulated CFC-free aerosol inhalers are ill founded. However, if given the choice, many patients prefer a DPI over the HFA inhaler. The transition offers an opportunity to review patients' current treatment and the proficiency of their inhaling technique. Moving to CFC-free inhalers will have revenue implications.  (+info)

The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earths ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989.. The parties to the Protocol meet once a year to make decisions aimed at ensuring the successful implementation of the agreement. These include adjusting or amending the Protocol, which has been done six times since its creation. The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons (HFCs) in 2016. These HFCs were used as replacements for a batch of ozone-depleting substances eliminated by the original Montreal Protocol. Although they do not deplete the ozone layer, they are known to be powerful greenhouse gases and, thus, contributors to climate change.. The Montreal Protocol provided a set of practical, actionable tasks ...
The latest Scientific Assessment of Ozone Depletion reveals a healing ozone layer, global warming reduction potential, and options for more ambitious climate action.. The quadrennial review from the Scientific Assessment Panel of the Montreal Protocol will be presented here at the 30th Meeting of the Parties to this historic accord. Its findings confirm first and foremost that actions taken under the Montreal Protocol have led to long-term decreases in the atmospheric abundance of controlled ozone-depleting substances (ODSs) and the ongoing recovery of stratospheric ozone.. Evidence presented by the authors shows that the ozone layer in parts of the stratosphere has recovered at a rate of 1-3% per decade since 2000. At projected rates, Northern Hemisphere and mid-latitude ozone is scheduled to heal completely by the 2030s followed by the Southern Hemisphere in the 2050s and polar regions by 2060. The ozone layer protects life on Earth from harmful levels of ultraviolet rays from the sun.. It is ...
i) Cost-benefit analysis. The Food and Drug Administration (FDA) analyzed the costs and benefits of this final rule. According to FDA, the benefits of this rule include environmental and public health improvements from protecting stratospheric ozone by reducing chlorofluorocarbons (CFCs) emissions. FDA also expect the benefits to include expectations of increased returns on investments in environmentally friendly technology and continued international cooperation to comply with the spirit of the Montreal Protocol, thereby potentially reducing future emissions of ozone-depleting substances (ODSs) throughout the world. FDA determined that the costs of the final rule would include increased spending for needed medicines used to treat asthma and Chronic Obstructive Pulmonary Disease (COPD). FDA determined that the social costs of the final rule include the health benefits lost through decreased use of medicines that may result from increased prices. FDA was unable to quantify the economic costs of ...
The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earths ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989.. The parties to the Protocol meet once a year to make decisions aimed at ensuring the successful implementation of the agreement. These include adjusting or amending the Protocol, which has been done six times since its creation. The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons (HFCs) in 2016. These HFCs were used as replacements for a batch of ozone-depleting substances eliminated by the original Montreal Protocol. Although they do not deplete the ozone layer, they are known to be powerful greenhouse gases and, thus, contributors to climate change.. The Montreal Protocol provided a set of practical, actionable tasks ...
Plasma technologies for the destruction of ozone-depleting substances are reviewed. Particular attention is paid to the PLASCON process, based on an argon plasm...
Paula Lombardi reviews a case where one of Canadas largest fastener distributers pled guilty to contravening the Ozone-Depleting Substances Regulations.
Introduction. Eugine Whint 7/12/2005 Chemistry 5G Chlorofluorocarbons (CFCs) Chlorofluorocarbons (CFCs) (also known as Freon) are non-toxic, non-flammable and non-carcinogenic. They contain fluorine atoms, carbon atoms and chlorine atoms. The 5 main CFCs include CFC-11 (trichlorofluoromethane - CFCl3), CFC-12 (dichloro-difluoromethane - CF2Cl2), CFC-113 (trichloro-trifluoroethane - C2F3Cl3), CFC-114 (dichloro-tetrfluoroethane - C2F4Cl2), and CFC-115 (chloropentafluoroethane - C2F5Cl). CFCs are widely used as coolants in refrigeration and air conditioners, as solvents in cleaners, particularly for electronic circuit boards, as a blowing agents in the production of foam (for example fire extinguishers), and as propellants in aerosols. Indeed, much of the modern lifestyle of the second half of the 20th century had been made possible by the use of CFCs. Man-made CFCs however, are the main cause of stratospheric ozone depletion. CFCs have a lifetime in the atmosphere of about 20 to 100 years, and ...
in Liang, Qing; Newman, Paul A; Reimann, Stefan (Eds.) SPARC Report on the Mystery of Carbon Tetrachloride (2016). The Montreal Protocol (MP) controls the production and consumption of carbon tetrachloride (CCl4 or CTC) and other ozone-depleting substances (ODSs) for emissive uses. CCl4 is a major ODS, accounting for ... [more ▼]. The Montreal Protocol (MP) controls the production and consumption of carbon tetrachloride (CCl4 or CTC) and other ozone-depleting substances (ODSs) for emissive uses. CCl4 is a major ODS, accounting for about 12% of the globally averaged inorganic chlorine and bromine in the stratosphere, compared to 14% for CFC-12 in 2012. In spite of the MP controls, there are large ongoing emissions of CCl4 into the atmosphere. Estimates of emissions from various techniques ought to yield similar numbers. However, the recent WMO/UNEP Scientific Assessment of Ozone Depletion [WMO, 2014] estimated a 2007-2012 CCl4 bottom-up emission of 1-4 Gg/year (1-4 kilotonnes/year), based on ...
Abstract. Coupling between the stratosphere and the troposphere allows changes in stratospheric ozone abundances to affect tropospheric chemistry. Large-scale effects from such changes on chemically produced tropospheric aerosols have not been systematically examined in past studies. We use a composition-climate model to investigate potential past and future impacts of changes in stratospheric ozone depleting substances (ODS) on tropospheric oxidants and sulfate aerosols. In most experiments, we find significant responses in tropospheric photolysis and oxidants, with small but significant effects on methane radiative forcing. The response of sulfate aerosols is sizeable when examining the effect of increasing future nitrous oxide (N2O) emissions. We also find that without the regulation of chlorofluorocarbons (CFCs) through the Montreal Protocol, sulfate aerosols could have increased by 2050 by a comparable amount to the decreases predicted due to relatively stringent sulfur emissions controls. ...
Phaseout of the fumigant methyl bromide has been a long process, with several delays and reassignment of target dates. The following overview of the impact of methyl bromide is adapted from the April 2001 issue of the USDA newsletter, Methyl Bromide Alternatives, available on the Internet at www.ars.usda.gov/is/np/mba/mebrhp.htm. To protect the earth from the detrimental effects of ozone depletion, an international treaty, the Montreal Protocol, was developed in the late 1980s. Since then, it has been controlling the production and trade of ozone-depleting substances on a global basis and has been signed by more than 160 nations. The treaty phases out chlorofluorocarbons and other ozone-depleting compounds, including methyl bromide. In 1995, Montreal Protocol signatory countries agreed to freeze production of methyl bromide at 1991 levels for developed countries. Total phaseout for developed countries will occur January 1, 2005, except for quarantine, critical, and emergency exemptions. ...
Phaseout of the fumigant methyl bromide has been a long process, with several delays and reassignment of target dates. The following overview of the impact of methyl bromide is adapted from the April 2001 issue of the USDA newsletter, Methyl Bromide Alternatives, available on the Internet at www.ars.usda.gov/is/np/mba/mebrhp.htm. To protect the earth from the detrimental effects of ozone depletion, an international treaty, the Montreal Protocol, was developed in the late 1980s. Since then, it has been controlling the production and trade of ozone-depleting substances on a global basis and has been signed by more than 160 nations. The treaty phases out chlorofluorocarbons and other ozone-depleting compounds, including methyl bromide. In 1995, Montreal Protocol signatory countries agreed to freeze production of methyl bromide at 1991 levels for developed countries. Total phaseout for developed countries will occur January 1, 2005, except for quarantine, critical, and emergency exemptions. ...
BACKGROUND: Hydrochlorofluorocarbons (HCFCs) are used increasingly in industry as substitutes for ozone-depleting chlorofluorocarbons (CFCs). Limited studies in animals indicate potential hepatotoxicity of some of these compounds. We investigated an epidemic of liver disease in nine industrial workers who had had repeated accidental exposure to a mixture of 1,1-dichloro-2,2,2-trifluoroethane (HCFC 123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC 124). All nine exposed workers were affected to various degrees. Both compounds are metabolised in the same way as 1-bromo-1-chloro-2,2,2-trifluoroethane (halothane) to form reactive trifluoroacetyl halide intermediates, which have been implicated in the hepatotoxicity of halothane. We aimed to test whether HCFCs 123 and 124 can result in serious liver disease. METHODS: For one severely affected worker liver biopsy and immunohistochemical stainings for the presence of trifluoroacetyl protein adducts were done. The serum of six affected workers and five ...
The Montreal Protocol led to a global phase-out of most substances that deplete the ozone layer, such as chlorofluorocarbons (CFCs). A happy side-effect of the gradual ban of these products is that Earths climate has also benefited because CFCs are also potent greenhouse gases. However, now a rebound effect threatens to accelerate the rate of global warming.. Hydrofluorocarbons (HFCs), which have been used in recent years in increasing quantities as substitutes for CFCs, are also climatically very active and many are also extremely long-lived. In the journal Science an international team of researchers recommends that the most potent of these gases also be regulated. This could save the positive side effect of the Montreal Protocol for the global climate.. It is regarded as the most successful international environmental agreement and has, to date, been ratified by 196 countries - the Montreal Protocol on Substances That Deplete the Ozone Layer. As a result, CFCs and ozone killers will ...
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The details of polar ozone hole formation differ from that of mid-latitude thinning, but the most important process in both is catalytic destruction of ozone by atomic halogens.[1] The main source of these halogen atoms in the stratosphere is photodissociation of man-made halocarbon refrigerants (CFCs, freons, halons.) These compounds are transported into the stratosphere after being emitted at the surface.[2] Both types of ozone depletion were observed to increase as emissions of Halocarbons increased. CFCs and other substances contributing to this effect are referred to as ozone-depleting substances (ODS). Since the ozone layer prevents most harmful UVB wavelengths (280-315 nm) of ultraviolet light (UV light) from passing through the Earths atmosphere, observed and projected decreases in ozone have generated worldwide concern. As a result, the Montreal Protocol has been adopted. The treaty bans the production of CFCs, halons as and other ozone-depleting chemicals such as carbon tetrachloride ...
Chlorofluorocarbons: A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, blowing agents, cleaning fluids, solvents, and as fire extinguishing agents. They have been shown to cause stratospheric ozone depletion and have been banned for many uses.
Ozone is a very important gas, because stratospheric ozone absorbs most harmful ultraviolet radiation, preventing it from reaching Earths surface. In the 1970s, researchers began to think that human activity could affect the ozone, even though they were focusing on the exhaust from supersonic airplanes and the space shuttle. However, after studying other possible causes for ozone depletion, the international community came to a consensus that certain manmade chemical compounds called chlorofluorocarbons (CFCs), were largely responsible for the ozone loss. As a result, the Montreal Protocol was adopted in 1987, calling for the worldwide elimination of CFCs and other ozone-destroying substances. So far, the Montreal Protocol has been signed by more than 160 nations. Image: Courtesy of NASA. The Protocol has been updated several times, most recently in 1995. Since knowledge of the ozone depletion problem continues to increase rapidly, the director of the United Nations Environment Programme (UNEP) ...
1990-26. Climate change is of key importance. We are committed to undertake common efforts to limit emissions of greenhouse gases, such as carbon dioxide. We strongly support the work of the Intergovernmental Panel on Climate Change (IPCC) and look forward to the release of its full report in August.. 1990-27. We reiterate our support for the negotiation of a framework convention on climate change, under the auspices of the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO).. 1990-28. The convention should be completed by 1992.. 1990-29. Work on appropriate implementing protocols should be undertaken as expeditiously as possible and should consider all sources and sinks.. 1990-30. We welcome the amendment of the Montreal Protocol to phase out the use of chlorofluorocarbons (CFCs) by the year 2000 and to extend coverage of the Protocol to other ozone-depleting substances.. 1990-31. We acknowledge that enhanced levels of cooperation will be necessary with ...
Montréal Protocol Following the discovery of the Antarctic ozone hole in late 1985, various governments recognized the need for stronger measures to reduce the production and consumption of a number of chlorofluorocarbons (CFCs).
Abstract. The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of ...
Chlorofluorocarbons have been banned since 1996 because they destroy the ozone layer. From the U.S. National Library of Medicine. [ ]
Chlorofluorocarbons are a family of halocarbons that contain only carbon, chlorine & fluorine. Used in blowing plastics & fridges. CFCs destroy the ozone layer
This improved version of the Trends Analysis is based on an interactive Flash module using a map-based interface, and it provides more precise year-wise data to the user. Based on official data reported by Governments to the Ozone Secretariat under Article 7 of the Montreal Protocol, the module presents country-wise analyses for the main substances controlled under the Protocol, i.e. chlorofluorocarbons (CFCs), hydrofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride (CTC), methyl chloroform (MCF). The graphics can be exported by the user for use in publications and presentations. The graphs include some or all of the following lines or data points: Consumption level: This appears for all countries. Production level: This appears only if the country is or was a producer of the specific ODS. Montreal Protocol reduction targets: The respective freeze or reduction target dates are included on the graph for reference.. Note that for HCFCs, since Article 5 countries have not yet ...
The stratospheric ozone layer is Earths sunscreen - protecting living things from too much ultraviolet radiation from the sun. The emission of ozone depleting substances has been damaging the ozone layer. But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. This website addresses stratospheric ozone issues, including the science of ozone depletion, EPAs regulatory approach to protecting the ozone layer, EPA-approved alternatives to ozone-depleting substances, and sun safety.. ...
Ive just arrived in Bangkok, where negotiators from around the world will convene next week for the mid-year meeting of the Montreal Protocol, the worlds most successful environmental treaty. There they will look for common ground on whether use this treaty to tackle some of the most potent heat-trapping pollutants, the super greenhouse gases known as hydrofluorcarbons, or HFCs. To recap, the phase-out of chlorofluorocarbons (CFCs) and other ozone-destroying chemicals under the Montreal Protocol has brought huge climate side-benefits because these chemicals are also powerful heat-trapping pollutants. Scientists tell us that phasing out CFCs worldwide delivered a climate protection bonus equivalent to 11 billion tons of CO2 reductions in 2010 alone - more than five times the carbon reductions of the Kyoto Protocol. Another way to look at it: The CFC phase-out bought us a 10-year delay on warming. Imagine what this roaring-hot, extreme-weather summer would have been like with all that extra ...
SAGE III on ISS is the fourth generation of a series of NASA Earth-observing instruments, known as the Stratospheric Aerosol and Gas Experiment. The first SAGE III instrument was launched on the Russian Meteor (satellite) spacecraft. The recently revised SAGE III will be mounted to the International Space Station where it will use the unique vantage point of ISS to make long-term measurements of ozone, aerosols, water vapor, and other gases in Earths atmosphere. The first SAGE instrument was launched February 18, 1979, to collect data on the various gases in the atmosphere, including ozone. The data collected on SAGE I and the following instrument SAGE II, which began taking measurements in October 1984, were critical to the discovery of the Earths ozone hole and the creation of 1987 Montreal Protocol, which banned ozone-depleting substances, such as chlorofluorocarbon (CFC). SAGE III on ISS is a nearly exact replica of SAGE III Meteor-3M, sent into orbit in 2001 on a Russian satellite. SAGE ...
Safeway, headquartered in Pleasanton, Calif., is the second largest grocery chain in North America with 1,412 stores in the United States and 2012 revenues of $44.2 billion. Safeway operates companies under the banner of Vons in southern California and Nevada, Randalls in Texas, and Carrs in Alaska. The settlement covers 659 Safeway stores - all Safeway stores in the United States that have commercial refrigeration equipment regulated by the CAA except for those stores in Safeways Dominicks Division, which was the subject of a 2004 settlement with the United States. The settlement was lodged today in the U.S. District Court for the Northern District of California, and is subject to a 30-day public comment period and final court approval. It will be available for viewing at www.justice.gov/enrd/Consent_Decrees. ...
Main page of Environment Canadas website. Environment Canada works to preserve and enhance the quality of the natural environment; conserve Canadas renewable resources; conserve and protect Canadas water resources; carry out meteorology and provide weather forecasts; enforce rules relating to boundary waters; and, coordinate environmental policies and programs for the federal government.
Information on the environment for those involved in developing, adopting, implementing and evaluating environmental policy, and also the general public
Next week, the twelfth Meeting Of The Parties To The Montreal Protocol on Substances that Deplete the Ozone Layer will take place in Burkina Faso to negotiate multi-governmental cooperation in the protection of the earths ozone layer. Given the recent collapse of the United Nations climate talks in the Hague, at which the US refused to agree to reduce global warming through stricter pollution controls (arguing instead for getting credit for carbon sinks), the importance of the upcoming meeting cannot be underestimated. The ozone layer exists in the stratosphere, a thin band of atmosphere 10-50km above the earths surface. This thin band absorbs (and thereby protects the earths surface from) harmful ultra-violet wavelengths (UV-B) that are produced in sunlight. The widespread use of human-produced chemicals that are ozone-depleting (such as chlorofluorocarbons -- used in air conditioning, or halocarbons -- used in fire extinguishers) has led to a reduction in stratospheric ozone, resulting ...
NASA scientists say theres been a 20 percent reduction in ozone depletion over the Antarctic compared to 12 years ago. Theyre crediting a worldwide effort started in the 1980s to ban production of ozone-depleting chemicals.
Since the start of the Montreal Protocol, the use of CFCs for Metered dose inhalers (MDIs) for the treatment of respiratory illnesses, such as asthma and chronic obstructive pulmonary disease (COPD), has dropped from a 1997 peak of around 10,000 tonnes to about 300 tonnes in 2013.. According to IPAC (International Pharmaceutical Aerosol Consortium), 2015 will be the final year of essential use exemptions for metered dose inhalers (MDIs).. MDIs were CFC based, but the Montreal Protocol Parties decided to leave them outside the CFC ban decisions and place them under the regime of Essential Use Exemptions CFCs have been replaced by HFCs (95 per cent HFC-134a, 5 per cent HFC-227ea) in new MDIs formulations. For an approximate 630 million HFC based MDIs manufactured annually worldwide, 9,400 tonnes HFCs were used in 2014.. By moving from CFC MDIs to HFC MDIs, besides the suppression of their action on the ozone layer, their climate impact has dropped by 90 %.. Alternatives to HFC based MDIs do exist ...
In 1985, the Vienna Convention for the Protection of the Ozone Layer was adopted and opened for signature. It entered into force on 22 Sep 1988 and established that secretariat functions would be carried out by the United Nations Environment Programme. Control of ozone-depleting substances was needed because ecological and health damage results from a depleted ozone layer due to more UV-B radiation reaching the Earths surface. Results include increased rates of skin cancers and eye cataracts, reduced plant and fishing yields from adverse effects on terrestrial and ocean ecosystems, weakened immune systems, and more damage to plastics. The subsequent Montreal Protocol established specific limits to production «[Image: the largest ozone hole ever recorded, Sep 2000, exposed all the Antarctic and reached the southern tip of Argentina.] ...
The scientific article enterprise has great potential to benefit all aspects of society, as well as to increase our understanding of the Creative Commons can you buy farxiga online Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. We urge you to take advantage of that opportunity, vote and have these issues are pervasive throughout the world we are witnessing attacks on scientific independence and the Montreal protocol, a global agreement to phase out ozone-depleting substances, saved the ozone layer. Those of us that have the good fortune of living in democratic societies will can you buy farxiga online have a chance to make our voices heard. Both public and political leaders once embraced great advances, such as leading centers for the benefit of society.. Across the world and at all levels of government. In addition, decisions on science funding and support should be can you buy farxiga ...
The atmosphere surrounding the earth is made up of several layers. These layers protect the earth and its inhabitants. The troposphere is the layer that we breathe. It goes about as high as the top of Mount Everest. The next atmospheric layer...
An Occupational Safety & Health Administration investigation into n-Propyl Bromide -- a chemical used as an adhesive and a solvent -- and recent publicity surrounding a furniture workers claim of illness due to nPB exposure may lead to heightened scrutiny of businesses and increased regulatory oversight of nPB and related chemicals.. Increased Use of nPB. In the mid-1980s, the United States and other countries moved to reduce and/or eliminate a number of chlorofluorocarbons and other chemicals that could damage the stratospheric ozone layer. In the 1990 amendments to the Clean Air Act, Congress established timetables for phasing out ozone-depleting substances (ODS) but also encouraged the use of alternative processes and product substitutes. 42 U.S.C. §7671c-e. In 1994, the EPA also established the Significant New Alternatives Policy (SNAP), whereby companies could petition the Environmental Protection Agency for the inclusion of certain chemicals as safer ODS alternatives. 42 U.S.C. ...
I have asthma and I normally used albuterol its generic and cheap and now they are taking them off the market because they destroy the ozone.So now they are switching to HFA Inhalers I got my first one and just let me say they are useless.The meds. do spray out good you have to pratically hold it down your thoat to get any in your lungs I think i end up eating most of it lol. I was wondering if anyone else is having problems with these HFA inhalers?They have me on proventil which is basically suppose to be albuterol, It just is not workig for me I use to be able to take one puff of albuterol but find myself taking a few puffs of proventil and it still feels like iam suffocating it feels like it doesnt work at all.Is there anything else i can switch to.This sucks I get to suffocate but aleast our ozone is not getting depleted,I do care about the enviroment but what are we suppose to do here?
The TOMS images of the Antarctic ozone hole caused worldwide alarm and thus played a key role in the Montreal Protocol and other international agreements to phase out the offending chemicals from our environment, said Goddards Pawan Bhartia, project scientist for the mission. In addition, measurements from the Stratospheric Aerosol and Gas Experiment, along with the Microwave Limb Sounder and the Halogen Occultation Experiment aboard the Upper Atmospheric Research Satellite, were important to scientists understanding of ozone ...
The Montreal Protocol in 1987 was one of those rare times in human history where we saw a problem and came together to implement a global solution. The problem was CFCs from aerosols and refrigerants that were chewing through atmospheric ozone. The Montreal Protocol was an agreement to phase-out the use of CFCs, and was recently lauded as a success by a NASA study using statellite data that showed the ozone hole over Antarctica recovering. ...
Significant reductions in stratospheric ozone occur inside the polar vortices each spring when chlorine radicals produced by heterogeneous reactions on cold particle surfaces in winter destroy ozone mainly in two catalytic cycles, the ClO dimer cycle and the ClO/BrO cycle. Chlorofluorocarbons (CFCs), which are responsible for most of the chlorine currently present in the stratosphere, have been banned by the Montreal Protocol and its amendments, and the ozone layer is predicted to recover to 1980 levels within the next few decades. During the same period, however, climate change is expected to alter the temperature, circulation patterns and chemical composition in the stratosphere, and possible geo-engineering ventures to mitigate climate change may lead to additional changes. To realistically predict the response of the ozone layer to such influences requires the correct representation of all relevant processes. The European project RECONCILE has comprehensively addressed remaining questions in ...
The Ministry of Environment & Forests (MoEF) is the nodal agency in the administrative structure of the Central Government for the planning, promotion, co-ordination and overseeing the implementation of Indias environmental and forestry policies and programmes.
Perhaps the single most successful international environmental agreement to date has been the Montreal Protocol Kofi Annan. Using atmospheric observations, we have monitored international progress on phasing out ozone depleting substances such as CFCs for over 30 years.. The Medusa Gas Chromatography Mass Spectrometry instrument, co-developed by the ACRG, provides high-precision measurements of more than 40 ozone depleting substances and other related gases. Using models, we have used these data to track how emissions of these substances continue to change in response to the Montreal Protocol.. Follow the links to the right for further information on individual projects involving the ACRG.. ...
Consider next the CFC2025 experiment, shown in Fig. 10b. This case looks like a typical global warming scenario, with both the P − E response and its attributions largely consistent with Fig. 12 (top) of Seager et al. (2010), which shows the global warming results for a CMIP3 multimodel average. The thermodynamic contribution is primarily an intensification of the climatological hydrological cycle (i.e., wet gets wetter and dry gets drier) but itself does not suggest any broadening of the subtropical dry zones. The contribution from the mean meridional circulation shows a tripolar response in each hemisphere away from the tropics (i.e., a moistening trend roughly poleward of 60°, a drying trend between 60° and 40°, and a moistening trend in the subtropics between 40° and 20°). This is consistent with the change in transient eddy momentum flux and vertical velocity (shown in Figs. 9d,h). The transient eddy momentum flux shifts poleward in both hemispheres and drives anomalous rising ...
International Relations theory (IR) involves the development of theoretical frameworks and theories to assist and make easy the comprehensio...
Find the blue Begin button to the right to start. Text of petition: The FDA, in compliance with the Montreal Protocol, has banned the use of life-saving CFC propellant albuterol asthma rescue inhalers in order to help restore the ozone layer, even though it has been widely acknowledged that these CFC inhaler emissions are too trivial to harm the ozone layer: Leslie Hendeles, University of Florida Professor of Pharmacy and Pediatrics, has noted that CFC inhalers release negligible amounts of the propellant and DO NOT POSE A THREAT TO OZONE DEPLETION. (LINK 1) The amount of CFCs in inhalers is minute, so BANNING THEM WONT MAKE ANY IMPROVEMENT (in the ozone layer). says Sallie Baliunas, an astrophysicist at Harvard University and the George Marshall Institute (LINK 2) CFC rescue inhalers have proven their safety, effectiveness, and reliability to tens of millions of asthma, COPD, cystic fibrosis, lung cancer, and other pulmonary patients for almost thirty years. Therefore, before the FDA could ...
We present the organization, instrumentation, datasets, data interpretation, modeling, and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment). AGAGE is distinguished by its capability to measure globally, at high frequency, and at multiple sites all the important species in the Montreal Protocol and all the important non-carbon-dioxide (non-CO2) gases assessed by the Intergovernmental Panel on Climate Change (CO2 is also measured at several sites). The scientific objectives of AGAGE are important in furthering our understanding of global chemical and climatic phenomena. They are the following: (1) to accurately measure the temporal and spatial distributions of anthropogenic gases that contribute the majority of reactive halogen to the stratosphere and/or are strong infrared absorbers (chlorocarbons, chlorofluorocarbons CFCs, bromocarbons, hydrochlorofluorocarbons HCFCs, hydrofluorocarbons HFCs and polyfluorinated ...
HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer. The safety and pharmacokinetics of HFC 134a and HFC 227 were assessed in two separate double-blind studies. Each HFC (hydrofluorocarbon) was administered via whole-body exposure as a vapor to eight (four male and four female) healthy volunteers. Volunteers were exposed, once weekly for 1 h, first to air and then to ascending concentrations of HFC (1000, 2000, 4000, and 8000 parts per million (ppm)), interspersed with a second air exposure and two CFC 12 (dichlorodifluoromethane) exposures (1000 and 4000 ppm). Comparison of either HFC 134a or HFC 227 to CFC 12 or air gave no clinically significant results for any of the measured laboratory parameters. ...
Freons (fluorocarbons and chlorofluorocarbons [CFCs)) historically have been widely used as aerosol propellants, in refrigeration units, in the manufacture of plastics, in foam blowing, and as degreasing agents. Under provisions of the Montreal Protocol of 1987, the use of CFCs is being phased out to avoid further depletion of stratospheric ozone. Nevertheless, freons remain in older refrigeration
In 1987, many countries signed the Montreal Protocol. This was an international agreement that attempted to ban and/or limit the production of Chlorofluorocarbons (CFCs). CFCs are industrial compounds that damage the ozone layer. They were found in most aerosol sprays and in many of the major asthma
Four new ozone-depleting gases have been detected in the atmosphere, despite a ban of similar compounds under an international treaty.
Chlorofluorocarbons and chlorocarbons[edit]. Chlorofluorocarbons, which are banned or highly regulated, were widely used ...
"Chlorofluorocarbons". NOAA National Centers for Environmental Information. NOAA. "Why Do Koreans Think Electric Fans Will Kill ... Ozone depletion is a separate problem caused by chlorofluorocarbons (CFCs) which have been released into the atmosphere. ...
CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, sufficiently long that it will ... 1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane or CFC-113, is a chlorofluorocarbon. It has the ... ". "Chlorofluorocarbons". Columbia Encyclopedia. 2008. Retrieved 2008-05-28. Zumdahl, Steven (1995). Chemical Principles. ...
Chlorofluorocarbons (CFCs) • Cyanide • DDT • Endocrine disruptors • Explosives • Environmental impact of the coal industry • ...
Prior to their phaseout some early refrigerants, such as chlorofluorocarbons (CFCs), contributed significantly to ozone ... University of California (April 18, 2017). "Chlorofluorocarbons and Ozone Depletion". American Chemical Society. Retrieved 2019 ...
"Chlorofluorocarbons and Ozone Depletion". American Chemical Society. Retrieved 4 June 2018. "Plutonium-238 Production for Space ... on The Vitamin B Complex The discovery of Ivermectin Infrared Spectrometer and the Exploration of Mars Chlorofluorocarbons and ...
"Chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs)". Minnesota Pollution Control Agency. 2009-11-16. Retrieved 2020-10-22 ...
These data show that CO 2 dominates the total forcing, with methane and chlorofluorocarbons (CFC) becoming relatively smaller ... chlorofluorocarbons (CFCs) 12 and 11; and fifteen other halogenated gases. These data do not include the significant forcing ...
As with fluorocarbons, chlorofluorocarbons and bromofluorocarbons are not flammable: they do not have carbon-hydrogen bonds to ... Substituting other halogens in combination with fluorine gives rise to chlorofluorocarbons (CFCs) or bromofluorocarbons (BFCs) ... "Potentially acceptable substitutes for the chlorofluorocarbons". International Journal of Thermophysics. 10 (3): 553-561. ...
"Chlorofluorocarbons (CFCs): Your Environment, Your Health , National Library of Medicine". Tox Town. Retrieved 2020-03-09. ... Almost always, this propellant gas is called chlorofluorocarbons (CFCs). CFCs have been proven to damage the ozone layer and ... As aforementioned, products packaged in aerosol cans currently contain chlorofluorocarbons (CFCs), which damages the ozone ...
Materials compatible with fluoroantimonic acid as a solvent include SO2ClF, and sulfur dioxide; some chlorofluorocarbons have ...
Chlorofluorocarbons also cause stratospheric ozone depletion. International efforts are ongoing under the Montreal Protocol and ... Nevertheless, the buildup of relatively small concentrations (parts per trillion) of chlorofluorocarbon, hydrofluorocarbon, and ...
... for example chlorofluorocarbons (CFCs) and formaldehyde. Volatile organic compounds are a subsection of Hydrocarbons that are ...
CS1 maint: discouraged parameter (link) Stix, T.H. (1993). "Removal of chlorofluorocarbons from the troposphere". International ...
Chlorofluorocarbons (CFCs) - harmful to the ozone layer; emitted from products are currently banned from use. These are gases ... methane and chlorofluorocarbons), particulates (both organic and inorganic), and biological molecules. Air pollution may cause ...
Ramanathan, V. (1975). "Greenhouse Effect Due to Chlorofluorocarbons: Climatic Implications". Science. 190 (4209): 50-51. ...
These include the chlorofluorocarbons (CFCs) and hydrofluororcarbons (HFC and HCFCs). As discussed below, a major reason that ... ISBN 978-0-495-55573-5. Ramanathan, Veerabhadran; 'Greenhouse Effect Due to Chlorofluorocarbons: Climatic Implications'; ... one year after Roland and Molina's much-more-celebrated paper on the ability of chlorofluorocarbons to destroy stratospheric ...
Chlorofluorocarbons have ODPs roughly equal to 1. Brominated substances have usually higher ODPs in range 5-15, because of more ... Ozone-Depletion and Chlorine-Loading Potential of Chlorofluorocarbon Alternatives Hurwitz, Margaret M.; Fleming, Eric L.; ...
Chlorofluorocarbons and chlorocarbonsEdit. Chlorofluorocarbons, which are banned or highly regulated, were widely used cleaning ...
CFCs that deplete the ozone layer are chlorofluorocarbons. Industry actually manufactured the chemicals and consumers purchased ...
"chlorofluorocarbons". Encyclopedia.com. Retrieved March 28, 2011.. *^ Laube, Johannes C.; Newland, Mike J.; Hogan, Christopher ... Chlorofluorocarbons (CFCs) and other halogenated ozone-depleting substances (ODS) are mainly responsible for man-made chemical ... These elements are found in stable organic compounds, especially chlorofluorocarbons, which can travel to the stratosphere ... "Stratospheric Ozone Depletion by Chlorofluorocarbons (Nobel Lecture)-Encyclopedia of Earth". Eoearth.org. Archived from the ...
Traditionally chlorofluorocarbons (CFCs) were the predominant fluorinated organic chemical. CFCs are identified by a system of ... Even though chlorofluorocarbons are widely banned, the replacement refrigerants are often other fluorinated molecules. ...
... diluents include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and carbon dioxide. Ethylene oxide is still ...
Exceptions include highly volatile, persistent substances such as chlorofluorocarbons. Stockholm Convention "Ridding the world ...
develops chlorofluorocarbons (CFC's) as a non-toxic refrigerant. The first warnings of damage to stratospheric ozone were ... 1974 - Chlorofluorocarbons are first hypothesized to cause ozone thinning. - National Reserves Management Act. - World human ...
He later earned the Nobel Prize in Chemistry for discovering how chlorofluorocarbons deplete the ozone layer. Dr. Molina is a ... "Chlorofluorocarbons and Ozone Depletion: A National Historic Chemical Landmark". International Historic Chemical Landmarks. ... This study soon led to research into chlorofluorocarbons (CFCs), apparently harmless gases that were used in refrigerants, ... of the 1995 Nobel Prize in Chemistry for his role in noting the threat to the Earth's ozone layer from chlorofluorocarbon (CFC ...
use of chlorofluorocarbons (CFCs) in refrigeration systems, and use of CFCs and halons in fire suppression systems and ...
It was commonly used before the popularisation of chlorofluorocarbons (Freons). Anhydrous ammonia is widely used in industrial ...
Class II substances consist of 33 different hydro-chlorofluorocarbons (HCFCs). The EPA has already begun plans to decrease ... This regulation aims to decrease emission of chlorofluorocarbons (CFCs) and other chemicals that are destroying the ...
1. 4, respectively). In the upper atmosphere, the photodissociation of normally unreactive chlorofluorocarbons (CFCs) by solar ... the use of chlorofluorocarbons as refrigerants has been restricted. Radicals play important roles in biology. Many of these are ...
... chlorofluorocarbon-11 and chlorofluorocarbon-12 in seawater". Deep-Sea Research Part I: Oceanographic Research Papers. 55 (8): ... Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CClmF4−m and C2ClmF6−m, ... Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CClmFnH4−m−n and ... Chlorofluorocarbons (CFCs) are anthropogenic compounds that have been released into the atmosphere since the 1930s in various ...
PRODUCT MATRIX - Chlorofluorocarbons (Site not responding. Last check: 2007-10-07). Chlorofluorocarbons are highly volatile ... FDA Consumer: Chlorofluorocarbons and the incredible shrinking ozone. Chlorofluorocarbons, or CFCs, have been at the center of ... Chlorofluorocarbons (CFC) are haloalkanes with both chlorine and fluorine. Chlorofluorocarbons (CFC) were developed by the ... Chlorofluorocarbons, fully halogenated (EHC 113, 1990). Throughout this monograph, percentages of chlorofluorocarbons in air ...
Make research projects and school reports about chlorofluorocarbons easy with credible articles from our FREE, online ... Chlorofluorocarbons Encyclopedia of Public Health COPYRIGHT 2002 The Gale Group Inc.. CHLOROFLUOROCARBONS. Chlorofluorocarbons ... Chlorofluorocarbon (CFC). A chlorofluorocarbon (CFC) is an organic compound typically consisting of chlorine, fluorine, carbon ... chlorofluorocarbon (CFC) Chemical compound in which hydrogen atoms of a hydrocarbon, such as an alkane, are replaced by atoms ...
Chlorofluorocarbons in the environment : the aerosol controversy. [T M Sugden; T F West; Society of Chemical Industry (Great ... Chlorofluorocarbons in the environment : the aerosol controversy. Author:. T M Sugden; T F West; Society of Chemical Industry ( ... schema:name "Chlorofluorocarbons in the environment : the aerosol controversy"@en ;. schema:productID "7737942" ;. schema: ... Chlorofluorocarbons in the environment.. Chichester, Eng. : Ellis Horwood for the Society of Chemical Industry ; New York : ...
Make research projects and school reports about CFCs (Chlorofluorocarbons) easy with credible articles from our FREE, online ... CFCs (Chlorofluorocarbons). Chlorofluorocarbons (CFCs), once described as "miracle chemicals," cause the breakdown of the ozone ... CFCs (Chlorofluorocarbons) Pollution A to Z COPYRIGHT 2004 The Gale Group Inc. ... "CFCs (Chlorofluorocarbons)." Pollution A to Z. . Encyclopedia.com. 17 Feb. 2018 ,http://www.encyclopedia.com,. ...
Protection against depletion of stratospheric ozone by chlorofluorocarbons available in on Powells.com, also read synopsis and ...
... or other chlorofluorocarbons in confined spaces may cause death by cardiac arrhythmia or asphyxiation. ... WARNING! Working with chlorofluorocarbon 113 (CFC-113) or other chlorofluorocarbons in confined spaces may cause death by ... EPA [1983]. Health assessment document for 1,1,2-trichloro-1,2,2- trifluoromethane (chlorofluorocarbon CFC-113), final report. ... Preventing Death from Excessive Exposure to Chlorofluorocarbon 113(CFC-113). ...
... * Share ... Many inhalers that do not use chlorofluorocarbons (CFC) are already available for the treatment of asthma and chronic ...
Chlorofluorocarbons: A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, ... Chlorofluorocarbons. Subscribe to New Research on Chlorofluorocarbons A series of hydrocarbons containing both chlorine and ... 06/01/1995 - "Metered dose inhalers for the treatment of asthma use chlorofluorocarbons as propellants. ". 12/01/1998 - "The ... 09/01/2005 - "This expansion has been driven by the Montreal protocol and the need to eliminate chlorofluorocarbons (CFCs) from ...
Among the most important of these are chlorofluorocarbons, or freons, for example, Freon 12. Chlorofluorocarbons, or CFCs, are ...
Eugine Whint 7/12/2005 Chemistry 5G Chlorofluorocarbons (CFCs) Chlorofluorocarbons (CFCs) (also known as Freon) are non-toxic, ...
Organofluorides, Organochlorides, Chlorofluorocarbons, Organobromides, Organoiodides. Organic halides are organic compounds ...
Main cause - chlorofluorocarbon (CFC). CFC man made gases used as. refrigerant (substance that make things. cold or freeze) and ... chlorofluorocarbon, nitrogen oxides and,. methane. The layer of gases trap the Suns heat. around the world. Greenhouse effect ...
Non-chlorofluorocarbon aerosol formulations DE69231991D1 (en) * 1991-06-10. 2001-09-13. Schering Corp. Chlorofluorocarbons ... Non-chlorofluorocarbon aerosol formulations US5314682A (en) * 1992-09-21. 1994-05-24. Great Lakes Chemical Corp.. Ozone ... Chlorofluorocarbon-free mometasone furoate aerosol formulations US6068832A (en) * 1996-08-29. 2000-05-30. Schering Corporation ... Chlorofluorocarbon-free mometasone furoate aerosol formulations US6039932A (en) * 1996-09-27. 2000-03-21. 3M Innovative ...
p>Chlorofluorocarbons have been banned since 1996 because they destroy the ozone layer. From the U.S. National Library of ... What are chlorofluorocarbons (CFCs)?. Chlorofluorocarbons (CFCs) are a group of manufactured chemical compounds that contain ... Chlorofluorocarbons have been banned since 1996 because they destroy the ozone layer. ... Chlorofluorocarbons. Haz-Map (National Library of Medicine) How to Keep Your Cool and Protect the Ozone Layer (Environmental ...
Sweden became the first country to ban the use of aerosol sprays which use chlorofluorocarbons (CFCs) as their propellants. ...
What is chlorofluorocarbons? Meaning of chlorofluorocarbons medical term. What does chlorofluorocarbons mean? ... Looking for online definition of chlorofluorocarbons in the Medical Dictionary? chlorofluorocarbons explanation free. ... chlorofluorocarbons. Also found in: Dictionary, Thesaurus, Financial, Encyclopedia, Wikipedia. chlorofluorocarbons. A range of ... Group I (chlorofluorocarbons 11, 12, 113, 114 and 115) for essential medical use: 155,460 kg weighted according to the ozone- ...
... chlorofluorocarbons (CFCs) and tritium/helium 3 (3H/3He)) and groundwater flow path analysis is useful for investigating ... Groundwater age dating through the combination of transient tracer methods (chlorofluorocarbons (CFCs) and tritium/helium 3 (3H ... Age dating of shallow groundwater with chlorofluorocarbons, tritium/helium: 3, and flow path analysis, southern New Jersey ... Age dating of shallow groundwater with chlorofluorocarbons, tritium/helium: 3, and flow path analysis, southern New Jersey ...
Metabolism of chlorofluorocarbons and polybrominated compounds by Pseudomonas putida G786(pHG-2) via an engineered metabolic ... Metabolism of chlorofluorocarbons and polybrominated compounds by Pseudomonas putida G786(pHG-2) via an engineered metabolic ... Metabolism of chlorofluorocarbons and polybrominated compounds by Pseudomonas putida G786(pHG-2) via an engineered metabolic ... Metabolism of chlorofluorocarbons and polybrominated compounds by Pseudomonas putida G786(pHG-2) via an engineered metabolic ...
Chlorofluorocarbons (CFCs) are man-made compounds which act to destroy this barrier. This paper presents (1) the first ... Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air S. J ... Abstract. The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the ... Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air, ...
Comparative effects of hydrofluoroalkane and chlorofluorocarbon beclomethasone dipropionate inhalation on small airways: ...
The fully halogenated ones with chlorine in their molecule are chlorofluorocarbons, referred to as CFCs. Those containing H ...
UNSPECIFIED (1980) Aspects of implementing a reduction in chlorofluorocarbon usage in aerosols. Final report, June 1980. [EU ... Aspects of implementing a reduction in chlorofluorocarbon usage in aerosols. Final report, June 1980. ...
CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, sufficiently long that it will ... 1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane or CFC-113, is a chlorofluorocarbon. It has the ... ". "Chlorofluorocarbons". Columbia Encyclopedia. 2008. Retrieved 2008-05-28. Zumdahl, Steven (1995). Chemical Principles. ...
Chlorofluorocarbons (CFC-11, CFC-12, CFC113), nutrients, dissolved oxygen, temperature, salinity and other measurements ... title: Chlorofluorocarbons (CFC-11, CFC-12, CFC113), nutrients, dissolved oxygen, temperature, salinity and other measurements ... 2019). Chlorofluorocarbons (CFC-11, CFC-12, CFC113), nutrients, dissolved oxygen, temperature, salinity and other measurements ... Chlorofluorocarbons (CFC-11, CFC-12, CFC113), nutrients, dissolved oxygen, temperature, salinity and other measurements ...
Chlorofluorocarbons and chlorocarbons[edit]. Chlorofluorocarbons, which are banned or highly regulated, were widely used ...
Chlorofluorocarbons are a family of halocarbons that contain only carbon, chlorine & fluorine. Used in blowing plastics & ... Chlorofluorocarbons (CFC). What are Chlorofluorocarbons (CFCs)?. Chlorofluorocarbons are a family of halocarbons that contain ... Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CClmF4-m and C2ClmF6-m, ... Notoriously chlorofluorocarbons were also widely used as aerosol propellants, cleansing agents for electrical and electronic ...
... and Japan Triamcinolone Ointment Chlorofluorocarbons Market cost, and Japan Triamcinolone Ointment Chlorofluorocarbons Market ... and Japan Triamcinolone Ointment Chlorofluorocarbons Market Size, and Japan Triamcinolone Ointment Chlorofluorocarbons Market ... and Japan Triamcinolone Ointment Chlorofluorocarbons Market trends, and Japan Triamcinolone Ointment Chlorofluorocarbons Market ... and Japan Triamcinolone Ointment Chlorofluorocarbons Market Growth, and Japan Triamcinolone Ointment Chlorofluorocarbons Market ...
Allocating Chlorofluorocarbon Permits: Who Gains, Who Loses, and What Is the Cost?. Jan 1, 1981 ... Economic Implications of Regulating Nonaerosol Chlorofluorocarbon Emissions: An Executive Briefing. Jan 1, 1980 ... Projections of Consumption of Products Using Chlorofluorocarbons in Developing Countries. Jan 1, 1987 ... Economic Implications of Regulating Chlorofluorocarbon Emissions from Nonaerosol Applications. Jan 1, 1980 ...
  • The invention of chlorofluorocarbons (CFCs) in the late 1920s and early 1930s stemmed from the call for safer alternatives to the sulfur dioxide and ammonia refrigerants used at the time. (factbites.com)
  • Chlorofluorocarbons , or CFCs, have been at the center of an intense debate for nearly 15 years over scientific uncertainties and the conflict between environmental protection and economic interests. (factbites.com)
  • Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CClmF4−m and C2ClmF6−m, where m is nonzero. (wikipedia.org)
  • Chlorofluorocarbons (CFCs) are a class of chemicals that contain only atoms of carbon, chlorine, and fluorine. (encyclopedia.com)
  • Chlorofluorocarbons (CFCs), once described as "miracle chemicals," cause the breakdown of the ozone layer that protects the earth from the sun's ultraviolet (UV) radiation. (encyclopedia.com)
  • The National Institute for Occupational Safety and Health (NIOSH) requests assistance in reducing the risk of death from cardiac arrhythmia and asphyxiation in workers exposed to 1,1,2-trichloro-1,2,2-trifluoroethane (more commonly known as CFC-113 or by a trade name such as Freon 113 ® , Genetron 113 ® , Halocarbon 113 ® , or Refrigerant 113 ® ) or to other chlorofluorocarbons (CFCs). (cdc.gov)
  • fluorocarbons that contain chlorine are called chlorofluorocarbons (CFCs). (cdc.gov)
  • Chlorofluorocarbons, or CFCs, are very stable molecules in the lower atmosphere. (blausen.com)
  • Eugine Whint 7/12/2005 Chemistry 5G Chlorofluorocarbons (CFCs) Chlorofluorocarbons (CFCs) (also known as Freon) are non-toxic, non-flammable and non-carcinogenic. (markedbyteachers.com)
  • What are chlorofluorocarbons (CFCs)? (nih.gov)
  • Chlorofluorocarbons (CFCs) are a group of manufactured chemical compounds that contain chlorine, fluorine, and carbon. (nih.gov)
  • An anisotropic distribution of electron density in chlorofluorocarbons (CFCs), make them suitable lewis base acceptors. (thefreedictionary.com)
  • These contain gases such as Chlorofluorocarbons (CFCs) and HCFCs, used for the coolant and insulation. (thefreedictionary.com)
  • Groundwater age dating through the combination of transient tracer methods (chlorofluorocarbons (CFCs) and tritium/helium 3 ( 3 H/ 3 He)) and groundwater flow path analysis is useful for investigating groundwater travel times, flow patterns, and recharge rates, as demonstrated by this study of the homogeneous shallow, unconfined Kirkwood-Cohansey aquifer system in the southern New Jersey coastal plain. (usgs.gov)
  • The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O 3 ). (atmos-chem-phys.net)
  • Chlorofluorocarbons (CFCs) are man-made compounds which act to destroy this barrier. (atmos-chem-phys.net)
  • CFCs (chlorofluorocarbons) produced in the 1920s were seen as ideal refrigerants because they did not have any of the previously described characteristics. (packerintersections.com)
  • into four parts: price benefits, reduction of chlorofluorocarbons (CFCs), oxygenate replacement and green fuel alternatives. (equities.com)
  • It was green, renewable and had the added benefit of reducing chlorofluorocarbons (CFCs) as well. (equities.com)
  • The FDA finished its phase-out of all inhaler medical products containing chlorofluorocarbons (CFCs) on December 31, 2013. (lww.com)
  • Chlorofluorocarbons (CFCs) have been used in the past as both refrigerants and aerosol propellants. (mapleridge.ca)
  • It appears to be clearly established that one factor responsible for the decrease of the ozone layer in the stratosphere is chlorofluorocarbons The reason for this is that liberated CFCs tend to percolate slowly up to the stratosphere, where they decompose by photodissociation releasing monoatomic chlorine. (allindianpatents.com)
  • The bomb contributions from the latter two are called transient tracers, as are the chlorofluorocarbons (CFCs), because they have been in the atmosphere for only a short time. (waterencyclopedia.com)
  • The chlorofluorocarbons, CFCs, are synthetic halogenated methanes. (waterencyclopedia.com)
  • BACKGROUND: Hydrochlorofluorocarbons (HCFCs) are used increasingly in industry as substitutes for ozone-depleting chlorofluorocarbons (CFCs). (uclouvain.be)
  • Attorney General Janet Reno also vowed that the Clinton administration will expand a crackdown on illegal imports of the chlorofluorocarbons, or CFCs , including the type commonly known by the brand name Freon. (thefreedictionary.com)
  • Probably the greatest example is CFCs, or chlorofluorocarbons. (forbes.com)
  • Chapter 5 Vocabulary air pollution emissions photochemical smog ozone acid rain ozone layer chlorofluorocarbons (CFCs) greenhouse effect global warming. (slideplayer.com)
  • Cutting down trees increases carbon dioxide levels Chlorofluorocarbons, CFCs, have been used in aerosols, such as hairspray cans, fridges and in making foam plastics. (slideplayer.com)
  • This product does not contain chlorofluorocarbons (CFCs) as the propellant. (nih.gov)
  • There is concern that halons are being broken down in the atmosphere to bromine, which reacts with ozone, leading to depletion of the ozone layer (this is similar to the case of chlorofluorocarbons such as freon ). (factbites.com)
  • Release of chlorofluorocarbons into the global environment during use, disposal of wastes, transport, and storage are an increasing concern because of the potential impact such uncontrolled releases may have on the future health of mankind, mainly through the depletion of stratospheric ozone. (factbites.com)
  • Chlorofluorocarbons and the depletion of stratospheric ozone. (factbites.com)
  • Chlorofluorocarbons are implicated in two major threats to the global environment: the greenhouse effect and the reduction of the ozone layer . (factbites.com)
  • As the chlorofluorocarbons break down, they release a chlorine atom which is capable of destroying tens of thousands of ozone molecules before being washed out of the atmosphere. (factbites.com)
  • Chlorofluorocarbons have been banned since 1996 because they destroy the ozone layer. (nih.gov)
  • When it became known that chlorofluorocarbons and hydrochlorofluorocarbons in refrigerants were contributing to depletion of the earth's protective ozone layer, NIST began a program (funded by the Department of Energy's Office of Basic Energy Sciences and Office of Building Technologies) to measure the properties of their replacements. (thefreedictionary.com)
  • The U.S. Environmental Protection Agency (EPA) has undertaken a major effort to study the potential effects of emitting chlorofluorocarbons and related potential ozone-depleting substances (PODs) into the atmosphere. (rand.org)
  • That blend would provide the beneficial green benefits of reduction of soot (SMOG), ground-level ozone and chlorofluorocarbons, and not add a potentially deadly ether compound back into the environment. (equities.com)
  • Scientists discovered in the 1970s that chlorofluorocarbons such as Freon were hurting Earth's ozone layer. (sciencenews.org)
  • Volatile chlorofluorocarbons are believed to cause depletion of the atmospheric ozone layer. (thefreedictionary.com)
  • Chlorofluorocarbons are compounds, similar to hydrocarbons, in which most, or all, of the hydrogen atoms have been replaced by various combinations of fluorine and chlorine atoms. (factbites.com)
  • Chlorofluorocarbons are highly volatile compounds, contributing to air pollution. (factbites.com)
  • Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CClmFnH4−m−n and C2ClxFyH6−x−y, where m, n, x, and y are nonzero. (wikipedia.org)
  • Metabolism of chlorofluorocarbons and polybrominated compounds by Pseudomonas putida G786(pHG-2) via an engineered metabolic pathway. (asm.org)
  • The present study investigated metabolism of brominated and chlorofluorocarbon compounds by the recombinant strain. (asm.org)
  • Among the most important of these are chlorofluorocarbons, or freons, for example, Freon 12. (blausen.com)
  • Likewise, Radiological Health), was summarized by although chlorofluorocarbons (Freon) were environmental media (such as surface water, used in significant quantities at each of the sediment, air, drinking water, groundwater, ORR facilities, they were judged unlikely to and food items). (cdc.gov)
  • Of the 682 million kilograms of chlorofluorocarbons consumed globally during 1991, the DuPont Corporation estimates the use for various applications as follows: 32 percent for refrigerants , 28 percent for blowing agents, 20 percent for cleaning agents, and 18 percent for propellants. (factbites.com)
  • Sweden and Norway have banned the use of chlorofluorocarbons as aerosol propellants. (factbites.com)
  • Canada's ban on chlorofluorocarbon propellants will be effective this May. (factbites.com)
  • Since the banning of the chlorofluorocarbons once used as propellants in the aerosol cans that dispense anything from shaving cream to deodorant, manufacturers have switched to natural gases like butane and propane. (thefreedictionary.com)
  • Notoriously chlorofluorocarbons were also widely used as aerosol propellants, cleansing agents for electrical and electronic components, and blowing agents in plastic insulation. (greenspec.co.uk)
  • Since then, concern over the chlorofluorocarbon propellants recommended for aerosols to be used for disinsection of aircraft has led to a reconsideration of their use. (who.int)
  • Aspects of implementing a reduction in chlorofluorocarbon usage in aerosols. (pitt.edu)
  • Chlorofluorocarbons (CFC) were developed by the American engineer Thomas Midgley in 1928 as a replacement for ammonia (NH chloromethane (CH Cl), and sulfur dioxide (SO), toxic but in common use at the time as refrigerants . (factbites.com)
  • On a global scale, man-made (anthropogenic) greenhouse gases, such as chlorofluorocarbon (CFC) refrigerants, methane, nitrous oxide, and carbon dioxide, are implicated in global warming and climate change. (informit.com)
  • Chlorofluorocarbons (CFC's) and hydrochlorofluorocarbons (HCFC's) are fully or partly halogenated paraffin hydrocarbons that contain only carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivative of methane, ethane, and propane. (wikipedia.org)
  • The heater uses carbon dioxide as a refrigerant instead of chlorofluorocarbons , which are commonly used in such devises. (thefreedictionary.com)
  • Chlorofluorocarbons are a group of chemicals discovered around 1930 that contain varying numbers of chlorine , fluorine, carbon and, sometimes, bromine atoms. (factbites.com)
  • Some of them are afforestation, selective deforestation, reduced release of carbon dioxide and other greenhouse gases by cutting down our use of chlorofluorocarbons , using catalytic converters in our cars and minimizing the combustion of fossil fuels that is actually shifting to renewable energy resources from non-renewable ones which is important to balance the ecosystem. (thefreedictionary.com)
  • Chlorofluorocarbons (CFC) are haloalkanes with both chlorine and fluorine. (factbites.com)
  • Liam S. ('18) wrote this piece for his Organic Chemistry class where they studied the environmental impacts of chlorofluorocarbons. (packerintersections.com)
  • s:9:\"\u0000*\u0000aucorp\";s:0:\"\";s:7:\"\u0000*\u0000isbn\";s:0:\"\";s:8:\"\u0000*\u0000coden\";s:0:\"\";s:8:\"\u0000*\u0000genre\";s:7:\"article\";s:7:\"\u0000*\u0000part\";s:0:\"\";s:9:\"\u0000*\u0000btitle\";s:94:\"In Memoriam: Professor Tetsuro Seiyama: Structure-Function Relationship in Catalytic Chemistry\";s:8:\"\u0000*\u0000title\";s:142:\"Decomposition of chlorofluorocarbons over metal phosphate catalysis. (inist.fr)
  • Equivalence of hydrofluoroalkane (HFA) and chlorofluorocarbons (CFC) formulations of inhaled beclomethasone. (ox.ac.uk)
  • To assess the long-term safety of hydrofluoroalkane 134a (HFA)-beclomethasone dipropionate (BDP) extrafine aerosol administered by the Autohaler compared with chlorofluorocarbon (CFC)-BDP administered by a press-and-breathe metered-dose inhaler (pMDI) and spacer (+S) in the treatment of children with asthma. (aappublications.org)
  • Development of the chlorofluorocarbon (CFC) technique as a tool for dating groundwater has occurred over the past 20 years, and a number of research publications have documented its use in specific aquifers. (environmental-expert.com)
  • The original debate over chlorofluorocarbons was set off in the early 1970s by chemists F. Sherwood Rowland and Mario Molina , both then with the University of California at Irvine. (factbites.com)
  • Many inhalers that do not use chlorofluorocarbons (CFC) are already available for the treatment of asthma and chronic obstructive pulmonary disease. (fda.gov)
  • ABSTRACT PROCESS FOR THE HYDROGENOLYSIS OF CHLOROFLUOROCARBONS AND OF CHLOROFLUOROHYDROCARBONS The invention relates to the gas-phase hydrogenolysis of chlorofluorocarbons or of chlorofluorohydrocarbons in the presence of a palladixim based catalyst deposited on a support. (allindianpatents.com)
  • The present invention relates to a process for the gas-phase hydrogenolysis chlorofluorocarbons or of chlorofluorohydrocarbons. (allindianpatents.com)
  • According to the invention there is provided a process for the gas-phase hydrogenolysis of chlorofluorocarbons or of chlorofluorohydrocarbons in the presence of a palladium-based catalyst on a support, wherein sulphur is incorporated into the catalyst. (allindianpatents.com)
  • Allocating Chlorofluorocarbon Permits: Who Gains, Who Loses, and What Is the Cost? (rand.org)
  • Alternatives to chlorofluorocarbons. (bmj.com)
  • Chlorofluorocarbon effects and regulations: hearing before the Subcommittee on the Upper Atmosphere of the Committee on Aeronautical and Space Sciences, United States Senate, Ninety-fourth Congress, second session, December 15, 1976. (factbites.com)
  • Association are well on course to meet the objective of eliminating the non-essential use of chlorofluorocarbons in their products by the end of this year. (parliament.uk)
  • In combination with effects predicted to occur as a result of increased combustion of fossil fuels, continued release of chlorofluorocarbons at current levels could also contribute to a potentially dangerous warming of the earth's atmosphere, altering climate and possible even partially melting the polar icecaps. (factbites.com)
  • Chlorofluorocarbons were chosen for their safety and for their advantageous chemical properties. (factbites.com)
  • These gases include carbon dioxide, methane, nitrogen oxide, and some engineered chemicals such as chlorofluorocarbons. (marketsandmarkets.com)
  • Greenhouse gases comprise Carbon Dioxide (CO2), Methane (CH4), Chlorofluorocarbon (CFC), and Nitrous oxide (N2O). (myseek.org)
  • The earth's climate is predicted to change because human activities are altering the chemical composition of the atmosphere through the buildup of greenhouse gases -- primarily carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. (epa.gov)
  • The nations of the world were able to come together to phase out ozone-depleting chlorofluorocarbons, so why can't we do the same to fight global warming? (earthtalk.org)
  • The 1987 Montreal Protocol mandated that countries phase out ozone-depleting chlorofluorocarbons (CFC) and similar chemicals used widely at the time for air conditioning and refrigeration. (epa.gov)
  • Chlorofluorocarbons a series of hydrocarbons containing both chlorine and fluorine. (biologyonline.com)
  • Its basically that ultraviolet light hits a chlorofluorocarbon (CFC) molecule, breaking off a chlorine atom. (shroomery.org)
  • CFC chlorofluorocarbon - A compound consisting of chlorine, fluorine and carbon. (brentanofabrics.com)
  • Most of the chlorine and bromine in the atmosphere comes from chlorofluorocarbons and halons, the chemically active forms of chlorine and bromine that were once used in refrigerants, foams, and aerosol-spray cans and are now banned by the Montreal Protocol . (nasa.gov)
  • In addition, several extinguishing agents (Halon 1211 and potential substitutes such as hydrogenated chlorofluorocarbons) are also considered hazardous chemicals by nature of their associated health hazards. (osha.gov)
  • In light of the current and future limitations on the production of chlorofluorocarbons both nationally and internationally, the development and utilization of environmentally safe alternatives to chlorofluorocarbons at this time will create such alternatives prior to the effective date of any comprehensive international, federal or state regulations banning the use of chlorofluorocarbons and halons. (ecode360.com)
  • Les gaz destructeurs de la couche d'ozone (CFC, chlore, bromure, halons) ont été progressivement éliminés dans les pays industrialisés après la signature du Protocole de Montréal, en 1987. (terresacree.org)
  • Proposal for a Council Decision authorizing the Commission to participate in the negotiations for a protocol on chlorofluorocarbons to the Vienna Convention for the Protection of the Ozone Layer. (pitt.edu)
  • Non-ozone layer destructive chlorofluorocarbon (CFC) alternatives have been initially used for laser-induced thermochemical etching of GaAs. (tms.org)
  • This informational piece, part of an interactive laboratory series for grades 8-12, explores the destruction of the ozone layer by chlorofluorocarbons. (nottingham.ac.uk)
  • Chlorofluorocarbons was one of the main reasons for the depletion in the ozone layer and the greenhouse gas effect. (eupedia.com)
  • In the late 1980s, however, chlorofluorocarbons were found to be contributing to the destruction of Earth's protective ozone layer. (greatachievements.org)
  • F. Sherwood Rowland, the founding University of California, Irvine professor who won a Nobel Prize for discovering that chlorofluorocarbons could destroy the Earth's ozone layer, has died, the university announced Monday. (nbclosangeles.com)
  • We are currently pumping pollutants known as chlorofluorocarbons into our own atmosphere as a byproduct of our technological activity. (slate.com)
  • But we do know that if we hadn't stopped putting chlorofluorocarbons into the atmosphere because of the Montreal Protocol , the Arctic depletion this year would have been much worse. (nasa.gov)
  • Tells how some of his proposals got lost in the shuffle such as his child-care proposal, his education proposals, the announcement that the U.S. would join the worldwide movement to reduce the amount of chlorofluorocarbons in the atmosphere, the new policy of economic help for Poland. (newyorker.com)
  • The Commission proposes to cut the use of chlorofluorocarbons in aerosols. (pitt.edu)
  • Aspects of implementing a reduction in chlorofluorocarbon usage in aerosols. (pitt.edu)
  • No, Glade ® Sprays and all other SC Johnson aerosols have been chlorofluorocarbon (CFC) free since 1975. (glade.com)
  • Task 1 Technical alternatives to selected chlorofluorocarbon uses. (epa.gov)
  • Aspects of effecting further reductions in chlorofluorocarbon usage in the EEC. (pitt.edu)
  • Chlorofluorocarbons are widely used in refrigeration and air-conditioning systems in a form commonly known as "Freon. (ecode360.com)
  • however, until such bans have been adopted by the appropriate agencies responsible action on the part of the City is necessary to reduce chlorofluorocarbon and halon use in order to promote the long-term health, safety and welfare of the general public, and the environment. (ecode360.com)
  • Proposal for a Council Decision concerning chlorofluorocarbons in the environment. (pitt.edu)
  • Chlorofluorocarbons in the environment. (pitt.edu)
  • Chlorofluorocarbons in the environment: information and basis for evaluation for the pursuit of Community policy. (pitt.edu)
  • Chlorofluorocarbons in the environment: updating the situation. (pitt.edu)
  • Chlorofluorocarbons in the environment: a reexamination of control measures. (pitt.edu)
  • 2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (usgs.gov)
  • Depending on what type of working fluid is used (ammonia, water, or chlorofluorocarbons), the piping in the heat pump system may require corrosion resistant stainless steel or aluminum. (encyclopedia.com)
  • The RSOW is identified and tracked as a layer with minimum potential vorticity and maximum chlorofluorocarbon-12. (mit.edu)
  • The recapturing and recycling of chlorofluorocarbons from auto air-conditioning units alone could eliminate approximately 20% of all chlorofluorocarbons used in the United States. (ecode360.com)