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Real Science

Chlorofluorocarbons … And the winner is???? Science!

Michael Rosenthal

(8/2016) One of the interesting things about science is that it is an evolving discipline. What seems to be evident and factual one day can turn out to be different as more knowledge is acquired. Don’t think that the laws of nature change…they are dependable and constant, but when we learn more facts about a particular topic, we sometimes must revise our analysis and conclusions.

A good example of this phenomenon involves the use of chlorofluorocarbons (CFCs). These chemicals are relatively simply structured molecules, consisting of chlorine and fluorine atoms bonded to a central carbon atom. The simplest example has only one carbon atom with a total of four chlorine or fluorine atoms bonded to it. The symmetry is tetrahedral (a four-sided geometric structure – remember high school geometry?), and it is derived from our earlier subject, methane, CH4. If both chlorines and fluorines are present, the geometry distorts slightly from a perfect tetrahedron because of the different size and electronic requirements of chlorine from fluorine.

These compounds have low toxicity, like their parent compound methane (CH4), and have low reactivity and low flammability. Their initial uses were as refrigerants, propellants in medicinal applications, and for degreasing solvents. Chlorodifluoromethane is a precursor to tetrafluoroethylene, a compound that is converted to Teflon. Carbon tetrachloride was used in fire extinguishers from the late nineteenth century until the 1940s. Freon is a group of these compounds, developed in the 1890s, which is used as a refrigerant, to replace ammonia and some other toxic compounds in common use in fire-fighting, and as the propellant in aerosol cans. The scientist who developed the uses for these chemicals in the 1920s, Thomas Midgley, once demonstrated the properties of the chemicals by inhaling a breath of Freon and then blowing out a candle with no harm to him!

So it sounds good, does it not? What more can one ask for, an easily manufactured, relatively low cost compound that has many uses and replaces more toxic chemicals?

But Mother Nature had a secret that took us a while to discover. In the 1980s it became a concern that these compounds had a negative impact on the ozone layer. Hence regulation of the use of these compounds came into play. The low reactivity of CFCs leads to a lifespan of the chemicals that can last as long as 100 years or more. During this time they diffuse into the upper stratosphere, where ultraviolet radiation breaks them down into highly reactive molecules of bromine and chlorine which are very reactive. These released molecules then attack the earth’s ozone layer!

The discovery of this phenomenon has led to regulation of the use of CFCs. In 1978 the United States banned the use of CFCs, such as Freon, in aerosol cans, which was the beginning of extensive regulatory actions regarding CFCs in the United States against their use, administered vigorously and continuously to the present time by The Food and Drug Administration and the Environmental Protection Agency. The Montreal Protocol of 1987 called for drastic reduction of CFCs, and in 1989, 12 European Community nations forged the Montreal Protocol, agreeing to work toward a ban on CFC use. The Protocol was strengthened in 1990. The Food and Drug Administration has monitored the role of the United States in their responsibility under the agreement reached in the Montreal Protocol. The time planned for complete elimination has passed; there have been smuggling issues that have delayed the total elimination of CFCs, which should have been reached by now. Existing use leads to 5,791 kilotons of CFCs in existing products in 2002 in refrigerators, air conditioners, and aerosol cans. In 2007 some 200 countries agreed to accelerate the elimination of CFC use, including the United States and China. To make things even worse, CFCs also act as a greenhouse gas to contribute to global warming.

On a more positive note, a recent report in 2016 states that the ozone layer over Antarctica is showing signs of healing. The adoption of Montreal Protocol has been shown to be the major factor that has led to this fact by a professor of climate sciences at The Massachusetts Institute of Technology, Susan Solomon. Dr. Solomon announced that both experimental and modeling evidence supports a slowing of the rate of ozone depletion, after a peak size in 2000. The importance of the recognition of this problem is reflected by the fact that

F. Sherwood Rowland, Mario Molina, and Paul J, Crytzen were awarded the Nobel Prize in Chemistry in 1995 for their contributions to the recognition of the ozone depletion problem. Last year a model predicted that the Antarctic hole might be gone by 2050, thanks to the Montreal Protocol. Mother Nature continues to make things better or worse. The eruption of the Chilean volcano Calbuco in 2015 created an ozone hole. Professor Solomon has said, "We can now be confident that the things we’ve done have put the planet on a path to heal."

We’ve written before about the over use of vitamins and the amounts of cash spent by the public on those which are of little or no use to their health. An article in a recent AARP Bulletin reinforces this fact. The report points out that Americans spend $37 billion on nutritional supplements annually. An attorney in Florida tells his story that at age 79 a pharmacist recommended he take a supplement rich in omega-3 fatty acids to improve short-term memory. Instead of helping him, however, it made him sick. He is now the plaintiff in a federal lawsuit accusing the drug chain in question of misleading advertising.

These supplements include vitamins, memory pills, sleep aids, muscle powders, and various "disease cures". A report showed that the percentage of adults between the ages of 62 and 85 rose from 51.8 to 63.7 percent between 2005 and 2011. These supplements are not regulated as medicine, but as food! For that reason, the manufacturers do not need to prove that their products are either effective or safe. Often label claims are false and sometimes could be dangerous. The industry is not policed, and misleading claims are often made.

One of the worst of these claims is the marketing of drugs that claim to help dementia and even Alzheimer’s disease. Mainstream science has yet to find a cure for these conditions. Senator Claire McCaskill has taken the lead from her position on the U.S. Senate Special Committee on Aging to seek information from retailers who make their claims, and the Justice Department has announced a nationwide sweep of more than 100 manufacturers and marketers of supplements to trace false unsubstantiated claims. This is only the tip of the iceberg. There are many supplement marketers claiming to solve all kinds of actual and potential medical problems. As I’ve said before, take notice when you see the statement, "this product has not been evaluated by the Food and Drug Administration. It is not intended to cure, treat or prevent any disease or illness". Put it back on the shelf and save your money.

Michael is former chemistry professor at Mount. St. Marys

Read other articles by Michael Rosenthal