Fluorocarbons are, in general, less toxic than the corresponding chlorinated or brominated hydrocarbons. Esta menor toxicidad puede deberse a una mayor estabilidad del enlace C-F y, tal vez también, a la menor solubilidad lipoide de las sustancias más fluoradas. Thanks to their low level of toxicity, it has been possible to select fluorocarbons that are safe for the uses for which they are intended.

In reality, volatile hydrocarbons have narcotic properties similar to those of chlorinated hydrocarbons, although weaker. Acute inhalation of 2,500 ppm of trichlorotrifluoromethane" causes intoxication and psychomotor incoordination in humans, an effect that is also observed with concentrations of 10,000 ppm (1%) of dichlorodifluoromethane"). Inhalation of dichlorodifluoromethane at concentrations of 150,000 ppm (15%) causes loss of consciousness. More than 100 deaths related to the inhalation of fluorocarbons have been recorded as a result of spraying aerosols containing dichlorodifluoromethane as a propellant into a paper bag and subsequently inhaling them. The TLV of 1000 ppm established by the American Conference of Government Industrial Hygienists (ACGIH) does not produce narcotic effects in humans.[3]​.

Fluoromethanes and fluoroethanes also do not produce toxic effects, such as liver or kidney damage, upon repeated exposure. Fluoralkenes, such as tetrafluoroethylene, hexafluoropropylene, or chlorotrifluoroethylene, can cause liver and kidney damage in experimental animals after prolonged and repeated exposures at appropriate concentrations.[3]​.

However, the acute toxicity of fluoroalkenes is surprising in some cases. Perfluorisobutylene is a good example of this. With an LC50 of 0.79 ppm for four hours of exposure in rats, it is more toxic than phosgene. Like this last product, it produces acute pulmonary edema. For their part, vinyl fluoride and vinylidene fluoride are fluoroalkanes of very low toxicity.[3]​.

Like many other solvent vapors and anesthetics used in surgery, volatile fluorocarbons can also cause arrhythmia or cardiac arrest when the body releases an abnormally high amount of adrenaline (such as in situations of distress, fear, excitement, or violent exercise). The concentrations necessary to produce this effect are much higher than those normally found in the industry.[3]​.

In dogs and monkeys, both chlorodifluoromethane and dichlorodifluoromethane rapidly cause respiratory depression, bronchoconstriction, tachycardia, myocardial depression, and hypotension at concentrations between 5 and 10%. Chlorodifluoromethane, unlike dichlorodifluoromethane, does not cause cardiac arrhythmias in monkeys (although it does in mice) and does not reduce lung function.[3]​.

Health and safety measures. All fluorocarbons undergo thermal decomposition when exposed to the action of flame or red-heated metals. The decomposition products of chlorofluorocarbons are hydrofluoric and hydrochloric acids, along with smaller amounts of phosgene and carbonyl fluoride. This last compound is very unstable to hydrolysis and quickly transforms into hydrofluoric acid and carbon dioxide in the presence of humidity.[3]​.

Mutagenicity and teratogenicity studies carried out on the three most important fluorocarbons from an industrial point of view (trichlorofluoromethane, dichlorodifluoromethane and trichlorotrifluorethane) have given negative results.[3]​.

Chlorodifluoromethane (R-22), once considered a possible aerosol propellant, was found to be mutagenic in bacterial mutagenesis studies. Lifetime exposure studies provided some evidence of carcinogenesis in male rats exposed to concentrations of 50,000 ppm (5%), but not to concentrations of 10,000 ppm (1%). This effect was not seen in female rats or other species. The International Agency for Research on Cancer (IARC) has classified this substance in Group 3 (limited evidence of carcinogenesis in animals). Some evidence of teratogenicity was also obtained in rats exposed to 50,000 ppm (5%), but not to 10,000 ppm (1%), nor in rabbits exposed to concentrations up to 50,000 ppm.[3]​.

Victims of fluorocarbon exposure should be evacuated from the contaminated area and given symptomatic treatment. They will not be administered adrenaline, as there is the possibility of causing arrhythmias or cardiac arrest.[3]​ The damage that chlorinated refrigerants CFC AND HCFC do to the OZONE LAYER, PLUS THE HIGH POTENTIAL of global warming generated by most CFC, HCFC, HFC refrigerants. They require the owners of equipment that use refrigerants to take action on what the industry offers in favor of the continuity of their refrigeration installations, in favor of the environment.

In recent years a great effort has been made to find alternatives to CFCs.

Among them, the most studied have been hydrochlorofluorcarbons (HCFC) and hydrofluorocarbons (HFC). These molecules contain, attached to carbon atoms, hydrogen, chlorine and/or fluorine atoms. Hydroxyl radicals, present in the troposphere, easily degrade the C--H bonds of these compounds. At the same time, the presence of these Cl and Br substituent compounds gives them some of the advantageous properties of CFCs: low reactivity and fire suppression, good insulators and solvents, and boiling points suitable for use in refrigeration cycles.

Some of the CFCs have already been replaced by these compounds. CHFCl (HCFC-22) is a refrigerant that can replace CClF (CFC-12) in the compressors of domestic air conditioning and refrigerator systems. For the manufacture of polyurethane foam insulation, CHCFCl (HCFC-141b) or CFCHCl (HCFC-123) can be used instead of CClF (CFC-11).

New technologies consider compounds other than HCFCs and HFCs as substitutes for CFCs. Both isobutane and dimethyl ether (mixed with water to reduce their flammability) can be used as aerosol propellants. Similarly, hydrocarbons have replaced CFCs as bubble-forming agents in foam manufacturing. The rigid foams used in the insulation of refrigerator walls, initially made up of CFC-11 and currently of HCFC-141b, will be replaced in the future with panels filled with a solid material and sealed under vacuum. The electronics industry is replacing CFCs, used as solvents for cleaning circuits, with aqueous detergent cleaners, or is developing new printing systems that reduce the number of cleaning steps necessary.

Replacing the fluids used in air conditioning and refrigerator systems is more difficult. There are many alternatives in perspective. One of them is the application of substances already used in the past for these purposes, such as ammonia and hydrocarbons.

However, its development has been slowed by the problems of ammonia corrosion and hydrocarbon flammability.

There are currently air conditioning systems that do not require a compressor. These are based on the combination of an evaporative cooling system and a desiccant to dry the cold air.

Currently, no suitable alternative has been found to halons, substances used to extinguish fires in closed spaces such as offices, airplanes and military tanks. Since production ceased in 1994, they have been subject to careful marketing, depending on the development of alternatives. Halons exhibit an attractive, hard-to-match combination of low reactivity and effective fire suppression. CFI is currently the most promising candidate, since like CFBr (halon-1301) it is heavy enough to extinguish fires. The C--I bond is easily broken by the action of UV photons, even at ground level, therefore the lifetime of the molecule is very short.

The change, from maximum CFC production to CFC substitution, is occurring faster than could have been anticipated a few years ago.

CFCs arose from the need to search for non-toxic substances that could serve as refrigerants for industrial applications, and Thomas Midgley was the one who discovered that these gases were harmless to humans, thus preventing thousands of accidental poisonings. Since at the time the use of CFCs was discovered there was not much information about ozone and the harmful effects of CFCs were unknown, Thomas Midgley himself died thinking that he had done a great service to humanity.

CFCs, also known commercially as freons, replaced ammonia and their use spread mainly in automobile air conditioners, refrigerators and industries. Starting in 1950, they began to be used as propelling agents for atomizers, in the manufacture of plastics and to clean electronic components.

The discoverers of the threat posed by the use of CFCs were the American chemist F. Sherwood Rowland, from the University of California, the Mexican chemist Mario J. Molina "Mario Molina (chemist)") from the Massachusetts Institute of Technology (MIT) and the Dutch Paul Crutzen, from the Max Planck Institute of Chemistry in Mainz"), Germany, architects of these discoveries, who on October 11, 1995 received the Nobel Prize in Chemistry in recognition for his research in this field.

A clear example of the CFC problem, of how the conflict developed and was resolved, is found in the book Billions by Carl Sagan (chapter 10: "A piece of the sky is missing").

However, there were other experts who contracted the hypothesis of the action of CFCs on the ozone. An example is the book by Rogelio Maduro") and Ralph Schauerhammer"), "The Holes in the Ozone Scare," published in 1992 by 21st Century Science Associates. ISBN 0-9628134-0-0. This informative book was answered in magazine articles at the time and its arguments do not correspond to the evidence that appeared in scientific magazine articles (reviewed and contrasted).

The latest major review of knowledge about the ozone hole was written and reviewed by some 300 scientists and was presented in Geneva on September 16, 2010, on the occasion of the UN International Day for the Preservation of the Ozone Layer.

Fluorocarbons are, in general, less toxic than the corresponding chlorinated or brominated hydrocarbons. Esta menor toxicidad puede deberse a una mayor estabilidad del enlace C-F y, tal vez también, a la menor solubilidad lipoide de las sustancias más fluoradas. Thanks to their low level of toxicity, it has been possible to select fluorocarbons that are safe for the uses for which they are intended.

In reality, volatile hydrocarbons have narcotic properties similar to those of chlorinated hydrocarbons, although weaker. Acute inhalation of 2,500 ppm of trichlorotrifluoromethane" causes intoxication and psychomotor incoordination in humans, an effect that is also observed with concentrations of 10,000 ppm (1%) of dichlorodifluoromethane"). Inhalation of dichlorodifluoromethane at concentrations of 150,000 ppm (15%) causes loss of consciousness. More than 100 deaths related to the inhalation of fluorocarbons have been recorded as a result of spraying aerosols containing dichlorodifluoromethane as a propellant into a paper bag and subsequently inhaling them. The TLV of 1000 ppm established by the American Conference of Government Industrial Hygienists (ACGIH) does not produce narcotic effects in humans.[3]​.

Fluoromethanes and fluoroethanes also do not produce toxic effects, such as liver or kidney damage, upon repeated exposure. Fluoralkenes, such as tetrafluoroethylene, hexafluoropropylene, or chlorotrifluoroethylene, can cause liver and kidney damage in experimental animals after prolonged and repeated exposures at appropriate concentrations.[3]​.

However, the acute toxicity of fluoroalkenes is surprising in some cases. Perfluorisobutylene is a good example of this. With an LC50 of 0.79 ppm for four hours of exposure in rats, it is more toxic than phosgene. Like this last product, it produces acute pulmonary edema. For their part, vinyl fluoride and vinylidene fluoride are fluoroalkanes of very low toxicity.[3]​.

Like many other solvent vapors and anesthetics used in surgery, volatile fluorocarbons can also cause arrhythmia or cardiac arrest when the body releases an abnormally high amount of adrenaline (such as in situations of distress, fear, excitement, or violent exercise). The concentrations necessary to produce this effect are much higher than those normally found in the industry.[3]​.

In dogs and monkeys, both chlorodifluoromethane and dichlorodifluoromethane rapidly cause respiratory depression, bronchoconstriction, tachycardia, myocardial depression, and hypotension at concentrations between 5 and 10%. Chlorodifluoromethane, unlike dichlorodifluoromethane, does not cause cardiac arrhythmias in monkeys (although it does in mice) and does not reduce lung function.[3]​.

Health and safety measures. All fluorocarbons undergo thermal decomposition when exposed to the action of flame or red-heated metals. The decomposition products of chlorofluorocarbons are hydrofluoric and hydrochloric acids, along with smaller amounts of phosgene and carbonyl fluoride. This last compound is very unstable to hydrolysis and quickly transforms into hydrofluoric acid and carbon dioxide in the presence of humidity.[3]​.

Mutagenicity and teratogenicity studies carried out on the three most important fluorocarbons from an industrial point of view (trichlorofluoromethane, dichlorodifluoromethane and trichlorotrifluorethane) have given negative results.[3]​.

Chlorodifluoromethane (R-22), once considered a possible aerosol propellant, was found to be mutagenic in bacterial mutagenesis studies. Lifetime exposure studies provided some evidence of carcinogenesis in male rats exposed to concentrations of 50,000 ppm (5%), but not to concentrations of 10,000 ppm (1%). This effect was not seen in female rats or other species. The International Agency for Research on Cancer (IARC) has classified this substance in Group 3 (limited evidence of carcinogenesis in animals). Some evidence of teratogenicity was also obtained in rats exposed to 50,000 ppm (5%), but not to 10,000 ppm (1%), nor in rabbits exposed to concentrations up to 50,000 ppm.[3]​.

Victims of fluorocarbon exposure should be evacuated from the contaminated area and given symptomatic treatment. They will not be administered adrenaline, as there is the possibility of causing arrhythmias or cardiac arrest.[3]​ The damage that chlorinated refrigerants CFC AND HCFC do to the OZONE LAYER, PLUS THE HIGH POTENTIAL of global warming generated by most CFC, HCFC, HFC refrigerants. They require the owners of equipment that use refrigerants to take action on what the industry offers in favor of the continuity of their refrigeration installations, in favor of the environment.

In recent years a great effort has been made to find alternatives to CFCs.

Among them, the most studied have been hydrochlorofluorcarbons (HCFC) and hydrofluorocarbons (HFC). These molecules contain, attached to carbon atoms, hydrogen, chlorine and/or fluorine atoms. Hydroxyl radicals, present in the troposphere, easily degrade the C--H bonds of these compounds. At the same time, the presence of these Cl and Br substituent compounds gives them some of the advantageous properties of CFCs: low reactivity and fire suppression, good insulators and solvents, and boiling points suitable for use in refrigeration cycles.

Some of the CFCs have already been replaced by these compounds. CHFCl (HCFC-22) is a refrigerant that can replace CClF (CFC-12) in the compressors of domestic air conditioning and refrigerator systems. For the manufacture of polyurethane foam insulation, CHCFCl (HCFC-141b) or CFCHCl (HCFC-123) can be used instead of CClF (CFC-11).

New technologies consider compounds other than HCFCs and HFCs as substitutes for CFCs. Both isobutane and dimethyl ether (mixed with water to reduce their flammability) can be used as aerosol propellants. Similarly, hydrocarbons have replaced CFCs as bubble-forming agents in foam manufacturing. The rigid foams used in the insulation of refrigerator walls, initially made up of CFC-11 and currently of HCFC-141b, will be replaced in the future with panels filled with a solid material and sealed under vacuum. The electronics industry is replacing CFCs, used as solvents for cleaning circuits, with aqueous detergent cleaners, or is developing new printing systems that reduce the number of cleaning steps necessary.

Replacing the fluids used in air conditioning and refrigerator systems is more difficult. There are many alternatives in perspective. One of them is the application of substances already used in the past for these purposes, such as ammonia and hydrocarbons.

However, its development has been slowed by the problems of ammonia corrosion and hydrocarbon flammability.

There are currently air conditioning systems that do not require a compressor. These are based on the combination of an evaporative cooling system and a desiccant to dry the cold air.

Currently, no suitable alternative has been found to halons, substances used to extinguish fires in closed spaces such as offices, airplanes and military tanks. Since production ceased in 1994, they have been subject to careful marketing, depending on the development of alternatives. Halons exhibit an attractive, hard-to-match combination of low reactivity and effective fire suppression. CFI is currently the most promising candidate, since like CFBr (halon-1301) it is heavy enough to extinguish fires. The C--I bond is easily broken by the action of UV photons, even at ground level, therefore the lifetime of the molecule is very short.

The change, from maximum CFC production to CFC substitution, is occurring faster than could have been anticipated a few years ago.

CFCs arose from the need to search for non-toxic substances that could serve as refrigerants for industrial applications, and Thomas Midgley was the one who discovered that these gases were harmless to humans, thus preventing thousands of accidental poisonings. Since at the time the use of CFCs was discovered there was not much information about ozone and the harmful effects of CFCs were unknown, Thomas Midgley himself died thinking that he had done a great service to humanity.

CFCs, also known commercially as freons, replaced ammonia and their use spread mainly in automobile air conditioners, refrigerators and industries. Starting in 1950, they began to be used as propelling agents for atomizers, in the manufacture of plastics and to clean electronic components.

The discoverers of the threat posed by the use of CFCs were the American chemist F. Sherwood Rowland, from the University of California, the Mexican chemist Mario J. Molina "Mario Molina (chemist)") from the Massachusetts Institute of Technology (MIT) and the Dutch Paul Crutzen, from the Max Planck Institute of Chemistry in Mainz"), Germany, architects of these discoveries, who on October 11, 1995 received the Nobel Prize in Chemistry in recognition for his research in this field.

A clear example of the CFC problem, of how the conflict developed and was resolved, is found in the book Billions by Carl Sagan (chapter 10: "A piece of the sky is missing").

However, there were other experts who contracted the hypothesis of the action of CFCs on the ozone. An example is the book by Rogelio Maduro") and Ralph Schauerhammer"), "The Holes in the Ozone Scare," published in 1992 by 21st Century Science Associates. ISBN 0-9628134-0-0. This informative book was answered in magazine articles at the time and its arguments do not correspond to the evidence that appeared in scientific magazine articles (reviewed and contrasted).

The latest major review of knowledge about the ozone hole was written and reviewed by some 300 scientists and was presented in Geneva on September 16, 2010, on the occasion of the UN International Day for the Preservation of the Ozone Layer.