Chlorofluorocarbons (CFCs) are gaseous chemicals that have been widely used over the past century since their inception in 1928. These products were investigated and their properties were shown to endanger public health by destroying the ozone layer, which is why its use was prohibited.
What are CFCs or chlorofluorocarbons
CFCs or chlorofluorocarbons are chemical substances made up of carbon, fluorine and chlorine atoms , belonging to the group of halocarbons, so they are not toxic or flammable. CFCs were first synthesized in 1928 by Thomas Midgley as an alternative to the chemicals used in refrigerators. After World War II, they were used as propellants in insecticides, paints, hair conditioners, and other health care products.
Between 1950 and 1960, they were used in home, car, and office air conditioners. The use of CFCs worldwide increased enormously with one million metric tons produced annually in the United States, being used in the manufacture of aerosols, refrigerants, blowing agent for foams and packaging material, as well as in solvents.
Chlorofluorocarbon compounds are volatile derivatives of methane, ethane, and propane. So some examples of more popular chlorofluorocarbons are:
- Methyl Chloroform – A well-known CFC, used in the past as a writing correction fluid under the trade name Tippex. It is estimated that it is the source responsible for more than half of the chlorine emissions in the atmosphere from CFCs.
- CFC-113 o tricloro-trifluoroetano.
- CFC-12, Dichlorodifluoromethane, or F-12 – Used extensively as refrigerants, aerosol propellants, solvents, and foam blowing agents. As they are not toxic or flammable, they had many uses, as well as their rapid transition from liquid to gas and vice versa, with a boiling temperature of -30 ºC.
- CFC-11, F-11 or trichlorofluoromethane : used for the same purposes as CFC-12. At one time it was one of the most common CFCs used as a propellant in nearly half of the aerosols manufactured worldwide. Its boiling temperature is 24 ºC.
- CFC-114 is dichlorotetrafluoroethane .
- CFC-115 or chloropentafluoroethane .
Products with CFCs or chlorofluorocarbons
Chlorofluorocarbons have no significant natural sources. They have been used as refrigerants, as propellants, as industrial solvents in the manufacture of foams and as cleaning agents in the manufacture of electronics. Therefore, if you wonder where chlorofluorocarbons are found , some of the products that contain CFCs, despite their use being prohibited since 1996, are:
- Refrigerants in air conditioners.
- Propellants in aerosols.
- Refrigerants in refrigerators.
- Haloalkanes in aircraft.
- Until 2009, CFCs could be found in inhalers to control asthma.
- Degreasing solvents.
After having explained what chlorofluorocarbons are, having seen some examples and discovered in what products they are found, let’s now see what are the effects of chlorofluorocarbons on the ozone layer, the atmosphere and our own health.
Being chemically inert compounds, it was initially thought that chlorofluorocarbons would be harmless to the atmosphere, but over time it was found that, upon reaching the stratosphere, CFCs reacted with ultraviolet radiation , which is more intense in this part of the world. atmosphere. When interacting with radiation, chlorofluorocarbons undergo photolytic decomposition that turns them into sources of inorganic chlorine. The released chlorine atoms catalyze the conversion of ozone molecules into oxygen, with the possible destruction of up to 100,000 ozone molecules for each chlorine atom. This is why CFCs are associated with the destruction of the ozone layer , which has very harmful consequences and encourages thechemical pollution , since ozone absorbs part of the sun’s ultraviolet radiation, specifically that between the wavelengths of 280 and 320 nm, which is harmful to both animal and plant organisms. Thus, the destruction of the ozone layer increases the amount of UV-B radiation reaching the Earth’s surface and endangers life on Earth.
The use of CFCs has resulted in the creation of holes in the ozone layer in different parts of the world and for that reason their use has been banned in a large number of countries. However, despite their prohibition, due to their chemical inertness and their insolubility, CFCs have long life expectancies in the atmosphere, which is why they continue to have an impact on it between tens and hundreds of years after their release. Due to all this, since 1987 in the Montreal protocol, CFCs have been recognized as harmful chemical compounds, which is why that protocol and other international agreements (such as the Kyoto Protocol of 1997) have determined the need to reduce and eliminate its use, since in addition to the aforementioned, CFCs alsothey act like greenhouse gases .
Health Effects of Chlorofluorocarbons
Although their use has been gradually decreasing, there may be old refrigerators and other appliances in service today with their consequent negative impact on health through inhalation, ingestion or other type of physical contact. Inhalation of CFCs affects the central nervous system, so that the health effects of chlorofluorocarbons can cause problems such as respiratory distress, kidney and liver problems, headaches, tremors, seizures and even heart rhythm disturbances and, in extreme cases, can lead to cases of suffocation and death. Contact of CFCs with the skin can cause skin irritation, dermatitis or even frostbite (in the case of exposure to pressurized CFCs, such as those present in refrigerants). In turn, the ingestion of CFCs can cause nausea, vomiting, diarrhea and other digestive disorders.