Ozone

The following information came from www.epa.gov
What is the ozone layer and why is it important?
The ozone layer is a concentration of ozone molecules in the stratosphere. About 90% of the planet's ozone is in the ozone layer. The layer of the Earth's atmosphere that surrounds us is called the troposphere. The stratosphere, the next higher layer, extends about 10-50 kilometers above the Earth's surface. Stratospheric ozone is a naturally-occurring gas that filters the sun's ultraviolet (UV) radiation. A diminished ozone layer allows more radiation to reach the Earth's surface. For people, overexposure to UV rays can lead to skin cancer, cataracts, and weakened immune systems. Increased UV can also lead to reduced crop yield and disruptions in the marine food chain. UV also has other harmful effects. The Earth's ozone layer protects all life from the sun's harmful radiation, but human activities have damaged this shield. Less protection from ultraviolet light will, over time, lead to higher skin cancer and cataract rates and crop damage. The U.S., in cooperation with over 160 other countries, is phasing out the production of ozone-depleting substances in an effort to safeguard the ozone layer.
I. The Ozone Layer
The Earth's atmosphere is divided into several layers. The lowest region, the troposphere, extends from the Earth's surface up to about 10 kilometers (km) in altitude. Virtually all human activities occur in the troposphere. Mt. Everest, the tallest mountain on the planet, is only about 9 km high. The next layer, the stratosphere, continues from 10 km to about 50 km. Most commercial airline traffic occurs in the lower part of the stratosphere.
Source: World Meteorological Organization, Scientific Assessment of Ozone Depletion: 1998, WMO Global Ozone Research and Monitoring Project - Report No. 44, Geneva, 1998.
As shown in the graph, most atmospheric ozone is concentrated in a layer in the stratosphere, about 15-30 kilometers above the Earth's surface. Ozone is a molecule containing three oxygen atoms. It is blue in color and has a strong odor. Normal oxygen, which we breathe, has two oxygen atoms and is colorless and odorless. Ozone is much less common than normal oxygen. Out of each 10 million air molecules, about 2 million are normal oxygen, but only 3 are ozone.
However, even the small amount of ozone plays a key role in the atmosphere. The ozone layer absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface. Most importantly, it absorbs the portion of ultraviolet light called UVB. UVB has been linked to many harmful effects, including various types of skin cancer, cataracts, and harm to some crops, certain materials, and some forms of marine life.
At any given time, ozone molecules are constantly formed and destroyed in the stratosphere. The total amount, however, remains relatively stable. The concentration of the ozone layer can be thought of as a stream's depth at a particular location. Although water is constantly flowing in and out, the depth remains constant.
While ozone concentrations vary naturally with sunspots, the seasons, and latitude, these processes are well understood and predictable. Scientists have established records spanning several decades that detail normal ozone levels during these natural cycles. Each natural reduction in ozone levels has been followed by a recovery. Recently, however, convincing scientific evidence has shown that the ozone shield is being depleted well beyond changes due to natural processes.
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II. Ozone Depletion
For over 50 years, chlorofluorocarbons (CFCs) were thought of as miracle substances. They are stable, nonflammable, low in toxicity, and inexpensive to produce. Over time, CFCs found uses as refrigerants, solvents, foam blowing agents, and in other smaller applications. Other chlorine-containing compounds include methyl chloroform, a solvent, and carbon tetrachloride, an industrial chemical. Halons, extremely effective fire extinguishing agents, and methyl bromide, an effective produce and soil fumigant, contain bromine. All of these compounds have atmospheric lifetimes long enough to allow them to be transported by winds into the stratosphere. Because they release chlorine or bromine when they break down, they damage the protective ozone layer. The discussion of the ozone depletion process below focuses on CFCs, but the basic concepts apply to all of the ozone-depleting substances (ODS).
In the early 1970s, researchers began to investigate the effects of various chemicals on the ozone layer, particularly CFCs, which contain chlorine. They also examined the potential impacts of other chlorine sources. Chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere. Chlorine compounds from these sources readily combine with water and repeated measurements show that they rain out of the troposphere very quickly. In contrast, CFCs are very stable and do not dissolve in rain. Thus, there are no natural processes that remove the CFCs from the lower atmosphere. Over time, winds drive the CFCs into the stratosphere.
The CFCs are so stable that only exposure to strong UV radiation breaks them down. When that happens, the CFC molecule releases atomic chlorine. One chlorine atom can destroy over 100,000 ozone molecules. The net effect is to destroy ozone faster than it is naturally created. To return to the analogy comparing ozone levels to a stream's depth, CFCs act as a siphon, removing water faster than normal and reducing the depth of the stream.
Large fires and certain types of marine life produce one stable form of chlorine that does reach the stratosphere. However, numerous experiments have shown that CFCs and other widely-used chemicals produce roughly 84% of the chlorine in the stratosphere, while natural sources contribute only 16%.
Large volcanic eruptions can have an indirect effect on ozone levels. Although Mt. Pinatubo's 1991 eruption did not increase stratospheric chlorine concentrations, it did produce large amounts of tiny particles called aerosols (different from consumer products also known as aerosols). These aerosols increase chlorine's effectiveness at destroying ozone. The aerosols only increased depletion because of the presence of CFC - based chlorine. In effect, the aerosols increased the efficiency of the CFC siphon, lowering ozone levels even more than would have otherwise occurred. Unlike long-term ozone depletion, however, this effect is short-lived. The aerosols from Mt. Pinatubo have already disappeared, but satellite, ground-based, and balloon data still show ozone depletion occurring closer to the historic trend.
One example of ozone depletion is the annual ozone "hole" over Antarctica that has occurred during the Antarctic Spring since the early 1980s. Rather than being a literal hole through the layer, the ozone hole is a large area of the stratosphere with extremely low amounts of ozone. Ozone levels fall by over 60% during the worst years.
In addition, research has shown that ozone depletion occurs over the latitudes that include North America, Europe, Asia, and much of Africa, Australia, and South America. Over the U.S., ozone levels have fallen 5-10%, depending on the season. Thus, ozone depletion is a global issue and not just a problem at the South Pole.
Reductions in ozone levels will lead to higher levels of UVB reaching the Earth's surface. The sun's output of UVB does not change; rather, less ozone means less protection, and hence more UVB reaches the Earth. Studies have shown that in the Antarctic, the amount of UVB measured at the surface can double during the annual ozone hole. Another study confirmed the relationship between reduced ozone and increased UVB levels in Canada during the past several years.
Laboratory and epidemiological studies demonstrate that UVB causes nonmelanoma skin cancer and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts. All sunlight contains some UVB, even with normal ozone levels. It is always important to limit exposure to the sun. However, ozone depletion will increase the amount of UVB, which will then increase the risk of health effects. Furthermore, UVB harms some crops, plastics and other materials, and certain types of marine life.
For more information, see the Ozone Depletion Process page.
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III. The World's Reaction
The initial concern about the ozone layer in the 1970s led to a ban on the use of CFCs as aerosol propellants in several countries, including the U.S. However, production of CFCs and other ozone-depleting substances grew rapidly afterward as new uses were discovered.
Through the 1980s, other uses expanded and the world's nations became increasingly concerned that these chemicals would further harm the ozone layer. In 1985, the Vienna Convention was adopted to formalize international cooperation on this issue. Additional efforts resulted in the signing of the Montreal Protocol in 1987. The original protocol would have reduced the production of CFCs by half by 1998.
After the original Protocol was signed, new measurements showed worse damage to the ozone layer than was originally expected. In 1992, reacting to the latest scientific assessment of the ozone layer, the Parties decided to completely end production of halons by the beginning of 1994 and of CFCs by the beginning of 1996 in developed countries.
Because of measures taken under the Protocol, emissions of ozone-depleting substances are already falling. Based on measurements of total inorganic chlorine in the atmosphere, which stopped increasing in 1997 and 1998, stratospheric chlorine levels have peaked and are no longer increasing. The good news is that the natural ozone production process will heal the ozone layer in about 50 years.
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IV. Stratospheric Protection Division
In addition to regulating the end of production of the ozone-depleting substances, the U.S. Environmental Protection Agency (EPA) implements several other programs to protect the ozone layer under Title VI of the Clean Air Act. These programs include refrigerant recycling, product labeling, banning nonessential uses of certain compounds, and reviewing substitutes.
Reports to the Nation: Our Ozone Shield
Written by the National Oceanic and Atmospheric Administration (NOAA), this booklet describes the history and science of ozone depletion.
Scientific Assessment of Ozone Depletion: 2002
This is the executive summary of the most recent World Meteorological Organization and United Nations Environmental Programme assessment. It contains the most up-to-date understanding of ozone depletion and reflects the thinking of over 250 international scientific experts who contributed to its preparation and review.


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How does ozone depletion occur?
It is caused by the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS), which were used widely as refrigerants, insulating foams, and solvents. The discussion below focuses on CFCs, but is relevant to all ODS. Although CFCs are heavier than air, they are eventually carried into the stratosphere in a process that can take as long as 2 to 5 years. Measurements of CFCs in the stratosphere are made from balloons, aircraft, and satellites.
When CFCs reach the stratosphere, the ultraviolet radiation from the sun causes them to break apart and release chlorine atoms which react with ozone, starting chemical cycles of ozone destruction that deplete the ozone layer. One chlorine atom can break apart more than 100,000 ozone molecules.
Other chemicals that damage the ozone layer include methyl bromide (used as a pesticide), halons (used in fire extinguishers), and methyl chloroform (used as a solvent in industrial processes for essential applications). As methyl bromide and halons are broken apart, they release bromine atoms, which are 40 times more destructive to ozone molecules than chlorine atoms.
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How do we know that natural sources are not responsible for ozone depletion?
While it is true that volcanoes and oceans release large amounts of chlorine, the chlorine from these sources is easily dissolved in water and washes out of the atmosphere in rain. In contrast, CFCs are not broken down in the lower atmosphere and do not dissolve in water. The chlorine in these human-made molecules does reach the stratosphere. Measurements show that the increase in stratospheric chlorine since 1985 matches the amount released from CFCs and other ozone-depleting substances produced and released by human activities.
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What is being done about ozone depletion?
In 1978, the use of CFC propellants in spray cans was banned in the U.S. In the 1980s, the Antarctic "ozone hole" appeared and an international science assessment more strongly linked the release of CFCs and ozone depletion. It became evident that a stronger worldwide response was needed. In 1987, the Montreal Protocol was signed and the signatory nations committed themselves to a reduction in the use of CFCs and other ozone-depleting substances.
Since that time, the treaty has been amended to ban CFC production after 1995 in the developed countries, and later in developing countries. Today, over 180 countries have ratified the treaty. Beginning January 1, 1996, only recycled and stockpiled CFCs will be available for use in developed countries like the US. This production phaseout is possible because of efforts to ensure that there will be substitute chemicals and technologies for all CFC uses.
EPA coordinates numerous regulatory programs designed to help the ozone layer and continues to be active in developing international ozone protection policies. Individuals can also help, primarily by ensuring that technicians working on air conditioning and refrigeration equipment are certified by EPA, that refrigerants are recaptured and not released, and by educating themselves about the issue of ozone depletion. A longer article explains EPA's ozone protection efforts in more detail.
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Is there general agreement among scientists on the science of ozone depletion?
Yes. Under the sponsorship of the UN Environment Programme (UNEP) and the World Meteorological Organization (WMO), the scientific community issues periodic reports. Almost 300 scientists worldwide drafted and reviewed the WMO/UNEP Scientific Assessment of Ozone Depletion: 2002. An international consensus about the causes and effects of ozone depletion has emerged. To obtain a copy of the executive summary of the assessment, please visit NOAA's web site
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Will the ozone layer recover? Can we make more ozone to fill in the hole?
The answers, in order, are: yes and no. We can't make enough ozone to replace what's been destroyed, but provided that we stop producing ozone-depleting substances, natural ozone production reactions should return the ozone layer to normal levels by about 2050. It is very important that the world comply with the Montreal Protocol; delays in ending production could result in additional damage and prolong the ozone layer's recovery. More detail on these questions is provided elsewhere on this web site
Will the Ozone Layer Recover? Can We Make More Ozone?
The answers are: yes, assuming full compliance with the Montreal Protocol, and no. It makes sense to explore the questions in reverse order, but understanding either answer requires some basic facts about how ozone levels remain relatively constant and what ozone depletion means. In this discussion, we are mainly concerned with global ozone depletion, as opposed to what happens during the annual Antarctic ozone hole .
Ozone molecules are constantly being produced and destroyed by different types of ultraviolet light from the sun. Normally, the production and destruction balances, so the amount of ozone at any given time is pretty stable. Think of the amount of ozone as the water level in a bucket with a small hole in the bottom and a hose adding water at the top. When you turn on the water, you'll find a balance point where the amount of water in the bucket stays constant, even though the hose is adding water and the hole is removing it. The addition and removal are happening at the same rate, so the water level stays the same. Note that the hole in the bucket is not analogous to the Antarctic ozone hole; the ozone hole is an area of severe depletion, but it is not a physical hole that drains away ozone.
Now pour in a glass of water. You'll see that the water just drains faster for a little while until the level returns to the previous depth. The balance is stable. That's because with more water in the sink, there's more pressure at the bottom, and the water drains faster. In the same way, if you dump more ozone into the ozone layer, the destruction process will speed up a little bit until the amount of ozone returns to the stable point.
The other difficulty with simply manufacturing ozone is that the sun provides huge amounts of energy for the ozone production process. In fact, to produce the amount of ozone normally in the ozone layer, you'd have to use about double the total annual U.S. electricity production. There's simply no way we could create ozone fast enough, in large enough quantities, to replace the natural ozone production process.
The issue with ozone-depleting substances is that they add chlorine and bromine to the ozone layer, which effectively widens the hole. Thus, the stable point is lower than it used to be; this lowering of the stable point represents ozone depletion. Since we can't make more ozone, the solution is to reduce the hole in the bucket back to its natural size. The only way to do that is to remove the excess chlorine and bromine from the stratosphere. And the only way to do that is to stop making CFCs and several other chemicals. Although several other measures have been proposed to accelerate the removal of chlorine and bromine from the stratosphere, none has proven to be practical, and most could produce unwanted side effects that are not understood very well.
Over time, stratospheric chlorine and bromine will combine with other chemicals and eventually fall back to Earth. That's the point of ending production of these chemicals under the Montreal Protocol and the Clean Air Act. The good news is that the stability works both ways. In our bucket, narrowing the hole allows the water inside to rise to a higher stable point. Similarly, by ending production of ozone depleters, we allow natural processes to remove excess chlorine and bromine, which slows the ozone destruction reactions to normal speeds, and the production process will have the chance to restore the ozone layer to normal levels. Scientists expect that with full compliance with the Montreal Protocol, the ozone layer will heal by about 2050.
Good Up High
What is ozone?
Ozone is a gas that occurs both in the Earth's upper atmosphere and at ground level. Ozone can be "good" or "bad" for your health and the environment, depending on its location in the atmosphere.
How Can Ozone Be Both Good and Bad?
Ozone occurs in two layers of the atmosphere. The layer closest to the Earth's surface is the troposphere. Here, ground-level or "bad" ozone is an air pollutant that is harmful to breathe and it damages crops, trees and other vegetation. It is a main ingredient of urban smog. The troposphere generally extends to a level about 6 miles up, where it meets the second layer, the stratosphere. The stratosphere or "good" ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays.
What is Happening to the "Good" Ozone Layer?
Ozone is produced naturally in the stratosphere. But this "good" ozone is gradually being destroyed by man-made chemicals referred to as ozone-depleting substances (ODS), including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, and methyl chloroform. These substances were formerly used and sometimes still are used in coolants, foaming agents, fire extinguishers, solvents, pesticides, and aerosol propellants. Once released into the air these ozone-depleting substances degrade very slowly. In fact, they can remain intact for years as they move through the troposphere until they reach the stratosphere. There they are broken down by the intensity of the sun's UV rays and release chlorine and bromine molecules, which destroy the "good" ozone. Scientists estimate that one chlorine atom can destroy 100,000 "good" ozone molecules.
Even though we have reduced or eliminated the use of many ODSs, their use in the past can still affect the protective ozone layer. Research indicates that depletion of the "good" ozone layer is being reduced worldwide. Thinning of the protective ozone layer can be observed using satellite measurements, particularly over the Polar Regions.
How Does the Depletion of "Good" Ozone Affect Human Health and the Environment?
Ozone depletion can cause increased amounts of UV radiation to reach the Earth which can lead to more cases of skin cancer, cataracts, and impaired immune systems. Overexposure to UV is believed to be contributing to the increase in melanoma, the most fatal of all skin cancers. Since 1990, the risk of developing melanoma has more than doubled.
UV can also damage sensitive crops, such as soybeans, and reduce crop yields. Some scientists suggest that marine phytoplankton, which are the base of the ocean food chain, are already under stress from UV radiation. This stress could have adverse consequences for human food supplies from the oceans.
What is Being Done About the Depletion of "Good" Ozone?
The United States, along with over 180 other countries, recognized the threats posed by ozone depletion and in 1987 adopted a treaty called the Montreal Protocol to phase out the production and use of ozone-depleting substances.
EPA has established regulations to phase out ozone-depleting chemicals in the United States. Warning labels must be placed on all products containing CFCs or similar substances and nonessential uses of ozone-depleting products are prohibited. Releases into the air of refrigerants used in car and home air conditioning units and appliances are also prohibited. Some substitutes to ozone-depleting products have been produced and others are being developed. If the United States and other countries stop producing ozone-depleting substances, natural ozone production should return the ozone layer to normal levels by about 2050.

Bad Nearby
What Causes "Bad" Ozone?
Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.
At ground level, ozone is a harmful pollutant. Ozone pollution is a concern during the summer months because strong sunlight and hot weather result in harmful ozone concentrations in the air we breathe. Many urban and suburban areas throughout the United States have high levels of "bad" ozone. But many rural areas of the country are also subject to high ozone levels as winds carry emissions hundreds of miles away from their original sources.
How Does "Bad" Ozone Affect Human Health and the Environment?
Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. "Bad" ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue.
Healthy people also experience difficulty breathing when exposed to ozone pollution. Because ozone forms in hot weather, anyone who spends time outdoors in the summer may be affected, particularly children, outdoor workers and people exercising. Millions of Americans live in areas where the national ozone health standards are exceeded.
Ground-level or "bad" ozone also damages vegetation and ecosystems. It leads to reduced agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased susceptibility to diseases, pests and other stresses such as harsh weather. In the United States alone, ground-level ozone is responsible for an estimated $500 million in reduced crop production each year. Ground-level ozone also damages the foliage of trees and other plants, affecting the landscape of cities, national parks and forests, and recreation areas.
What Is Being Done About "Bad" Ozone?
Under the Clean Air Act, EPA has set protective health-based standards for ozone in the air we breathe. EPA, state, and cities have instituted a variety of multi-faceted programs to meet these health-based standards. Throughout the country, additional programs are being put into place to cut NOx and VOC emissions from vehicles, industrial facilities, and electric utilities. Programs are also aimed at reducing pollution by reformulating fuels and consumer/commercial products, such as paints and chemical solvents, that contain VOC. Voluntary programs also encourage communities to adopt practices, such as carpooling, to reduce harmful emissions.
We live with ozone every day. It can protect life on earth or harm it, but we have the power to influence ozone's impact by the way we live.


Actions You Can Take
High-Altitude "Good" Ozone
Protect yourself against sunburn. When the UV Index is "high" or "very high": Limit outdoor activities between 10 am and 4 pm, when the sun is most intense. Twenty minutes before going outside, liberally apply a broad-spectrum sunscreen with a Sun Protection Factor (SPF) of at least 15. Reapply every two hours or after swimming or sweating. For UV Index forecasts, check local media reports or visit: www.epa.gov/sunwise/uvindex.html
Use approved refrigerants in air conditioning and refrigeration equipment. Make sure technicians that work on your car or home air conditioners or refrigerator are certified to recover the refrigerant. Repair leaky air conditioning units before refilling them.
Ground-Level "Bad" Ozone
Check the air quality forecast in your area. At times when the Air Quality Index (AQI) is forecast to be unhealthy, limit physical exertion outdoors. In many places, ozone peaks in mid-afternoon to early evening. Change the time of day of strenuous outdoor activity to avoid these hours, or reduce the intensity of the activity. For AQI forecasts, check your local media reports or visit: www.airnow.gov
Help your local electric utilities reduce ozone air pollution by conserving energy at home and the office. Consider setting your thermostat a little higher in the summer. Participate in your local utilities' load-sharing and energy conservation programs.
Reduce air pollution from cars, trucks, gas-powered lawn and garden equipment, boats and other engines by keeping equipment properly tuned and maintained. During the summer, fill your gas tank during the cooler evening hours and be careful not to spill gasoline. Reduce driving, carpool, use public transportation, walk, or bicycle to reduce ozone pollution, especially on hot summer days.
Use household and garden chemicals wisely. Use low VOC paints and solvents. And be sure to read labels for proper use and disposal.
For air program information, contact your Regional EPA Office:
...or visit EPA's website at http://www.epa.gov/air
This information was taken from www.epa.gov. For more information on this topic pleas visit www.epa.gov.

What Has EPA Done About Ozone Depletion?
EPA History Office's Ozone Depletion Site
In the 1970s, scientists first grew concerned that certain chemicals could damage the earth’s protective ozone layer. In the early 1980s, these concerns were validated by the discovery of thinning of the ozone layer over Antarctica in the southern hemisphere. While the ozone did not completely disappear in this area, it was so thin that scientists and the popular press started talking about an ozone hole .
A compromised ozone layer -- and the resulting increase in ultraviolet (UV) radiation hitting the earth’s surface -- can have serious consequences. Overexposure to UV radiation in humans can cause a range of health effects, including skin damage (skin cancers and premature aging), eye damage (including cataracts), and suppression of the immune system. Scientific studies also suggest a link between ultraviolet radiation and adverse effects on some animal and plant life and some plastic materials.
Because of the risks posed by ozone depletion, leaders from many countries decided to craft a workable solution. Since 1987, over 180 nations have ratified a landmark environmental treaty, the Montreal Protocol on Substances that Deplete the Ozone Layer. The Protocol’s chief aim is to reduce and eventually eliminate the production and use of man-made ozone depleting substances, or ODS. By agreeing to the terms of the Montreal Protocol, signatory nations -- including the United States -- committed to take actions to protect the ozone layer, hoping in the long-term to reverse the damage that had been done by the use of ozone depleting substances.
Why does the U.S. need regulations to protect the ozone layer?
As part of the United States’ commitment to implementing the Montreal Protocol, the U.S. Congress amended America’s Clean Air Act, adding provisions (under Title VI) for protection of the ozone layer. Most importantly, the amended Act required the gradual end to the production of chemicals that deplete the ozone layer.
The U.S. federal agency primarily responsible for the management of air quality and atmospheric protection issues is the U.S. Environmental Protection Agency. The Clean Air Act amendments passed by Congress require that EPA develop and implement regulations for the responsible management of ozone-depleting substances in the United States.
Under the Clean Air Act, EPA has created several regulatory programs to address numerous issues, including:
ending the production of ozone-depleting substances
ensuring that refrigerants and halon fire extinguishing agents are recycled properly
identifying safe and effective alternatives to ozone-depleting substances
banning the release of ozone-depleting refrigerants during the service, maintenance, and disposal of air conditioners and other refrigeration equipment
requiring that manufacturers label products either containing or made with the most harmful ODS.
With input from industry groups, environmentalists, and the public, EPA has published a range of regulations for the protection of the ozone layer. Because of their relatively high ozone depletion potential, several man-made compounds including chlorofluorocarbons (CFCs), carbon tetrachloride, methyl chloroform, and halons were targeted first for phaseout. EPA is developing additional regulations under its ozone protection program for the continued protection of the environment and public health.
EPA is also charged with enforcement of these regulations. Enforcement actions, which are handled through headquarters and at the local level primarily through EPA’s ten regional offices, range from civil fines to criminal prosecutions. To date, several people have been imprisoned for breaking ozone protection laws, and many more have been fined.
Besides implementing and enforcing ozone-protecting regulations in the U.S., EPA continues to work with other U.S. government agencies, including the State Department, Department of Justice, U.S. Customs and Border Service, as well as with international governments to pursue ongoing amendments to the Montreal Protocol and other treaties. These refinements to the Protocol and other treaties are based on ongoing scientific assessments of ozone depletion which are coordinated by the United Nations Environment Programme and the World Meteorological Organization, with cooperation from EPA and other agencies around the globe.
In addition, to help protect the American public from the health effects of overexposure to UV radiation, EPA maintains several education and outreach projects. Chief among these is the UV Index, a tool that provides a daily forecast of the next day’s likely UV levels in 58 cities across the United States. The UV Index, which EPA launched in partnership with the National Weather Service, serves as the cornerstone of EPA’s SunWise School Program, the goal of which is to educate young children and their caregivers about the health effects of overexposure to the sun, as well as simple steps that people can take to avoid overexposure.