Fluorocarbon Gases
1
Fluorocarbon Gases An instructive example of the im- portance of analytical chemistry in to- day's world is afforded by a consider- ation of fluorocarbons in the atmo- sphere. Recently, it has been noted that very stable fluorocarbon gases re- leased by aerosol sprays and air condi- tioners and refrigerants, in which they act as coolants, slowly rise to the ozone layer (altitude of 10-40 miles with the heaviest concentration, 5 ppm, at 15 miles). It is feared that these fluorocarbon gases break down by strong ultraviolet radiation and then react with the ozone layer and will reduce this protective layer as much as 10% by 1985 to 1990. Since this protective ozone layer absorbs en- ergetic UV radiation and thus protects life from excessive radiation damage, destruction of this layer has potential disastrous effects for life on earth. The Subcommittee on Public Health and Environment in the U.S. House of Representatives held hear- ings on the threat to the protective ozone layer of fluorocarbon gases in December 1974 in consideration of a bill, HR. 17577, which could lead to a ban on aerosol sprays containing fluo- rocarbon gases. This bill was intro- duced by U.S. Representatives M. L. Esch (R-Mich.) and Paul G. Rogers (D-Fla.), chairman of the Subcommit- tee. Testifying before the Subcommit- tee, Ralph J. Cicerone, associate re- search scientist in the Space Physics Research Laboratory at the University of Michigan and author of a research report (Science, September 27,1974) which brought this problem to public attention, says that claims that "natu- ral processes" would destroy the fluo- rocarbon gases before they reach the ozone shield "have been dismissed with evidence." He said all recent pa- pers on the subject substantiate the seriousness of the problem. He out- lined five research projects aimed at determining the danger of the threat in a short period of time. William Driver, president of the Manufacturing Chemists Assoc. (MCA), in a letter (which was released to the press) to Chairman Rogers of the Subcommittee, pointed to some of the developments that led to the dis- covery of fluorocarbons in the atmo- sphere and outlined past and future fluorocarbon research projects spon- sored by MCA. The MCA-sponsored research is supported by all six U.S. producers of fluorocarbon propellants and refrigerants, plus 13 groups based in other countries. Research is under Editors' Column way at the University of Reading (En- gland), the University of California (Riverside), and the University of Montreal. The impetus for MCA's fluorocarbon research efforts as delin- eated by Mr. Driver in his letter is worth quoting: "In the early 1960's Dr. James E. Lovelock, University of Reading (En- gland), invented a new technique for direct measurement of certain chemi- cal compounds. In the late 1960's he refined this technique to the point where it became possible to measure certain trace component gases in the atmosphere. By 1970, for the first time, if was possible to measure the amounts of simple organic molecules such as carbon tetrachloride, trichlo- roethane, and fluorocarbon com- pounds in the atmosphere." Dr. Lovelock's early measurements of trichlorofluoromethane (fluorocar- bon 11) and carbon tetrachloride led to his suggestion that carbon tetra- chloride had some natural origin and that fluorocarbon 11 profiles were consistent with its man-made origin. The role of analytical chemistry in MCA's current fluorocarbon gas re- search program is readily apparent by summing their goals: • "Continued measurement of fluo- rocarbon concentrations in the lower atmosphere to determine the rate of accumulation, the rate of diffusion into southern latitudes, and the rate of diffusion into the stratosphere • "Evaluation of potential removal mechanisms for fluorocarbon com- pounds in the troposphere • "Determination of possible chem- ical reactions of fluorocarbons and chlorine with active species which may exist in the high troposphere or in the stratosphere • "Direct measurement of as many stable chlorine-bearing species in the troposphere and stratosphere as possi- ble • "Development of analytical meth- ods for determination of chlorine oxide radical (CIO) • "Direct measurement of chlorine oxide radical (CIO) in the stratosphere between 50,000 and 100,000 feet." Thus, developments in analytical chemistry made possible the discovery of fluorocarbons in the atmosphere, and hopefully, developments in ana- lytical chemistry will play a key part in resolving the ensuing questions on the dangers posed by these fluorocar- bon gases. Josephine Petruzzi SCIENTISTS Do you encounter difficulties in handling 3 H and/or 14 C labeled sample materials for Liquid Scin- tillation Counting? or is your equipment outdated? or don't you possess the necessary equip- ment? or are you simply dis- satisfied with the data results? or are the expenses involved too high? Then it is time to have a closer look at PEMLAB and its services. We process (preparation-counting- data reduction) tritium and/or carbon-14 labeled materials such as: adipocere — bacteria — bladder — bone — brain — crude oil — egg shell — fat — feces — fur — gels — glands — hair — heart — insects — intestines — kidney — liver — lung — mi II i pore filters — muscle — plant tissue — plasma — plastics — skin — soil — spleen — thin layer scrapes — toluene — urine — water — whole blood — wool — etc., etc. A major breakthrough in Sample Preparation now utilized at PEM- LAB. No worries about: Sample throughput — Sample size — Low specific activity — Sample handl- ing — Unnecessary experimental errors — Down time of the equip- ment — turnover time — error inducing facts in double labeled experiments (we separate the iso- topes before counting.) Unique TRIAL offer and fabulous quantity discounts. For more information, please contact: Peter Mertens, Jr. PEMLAB CO. 8826 Ogden Ave. Brookfield, III. 60513 (312) 485-3316 Preparation * Counting * Data Reduction Try It Before You Buy It. * TRAINING WORKSHOPS LECTURES CIRCLE 193 ON READER SERVICE CARD ANALYTICAL CHEMISTRY, VOL. 47, NO. 3, MARCH 1975 · 361 A
Transcript of Fluorocarbon Gases
Fluorocarbon Gases An instructive example of the im
portance of analytical chemistry in today's world is afforded by a consideration of fluorocarbons in the atmosphere. Recently, it has been noted that very stable fluorocarbon gases released by aerosol sprays and air conditioners and refrigerants, in which they act as coolants, slowly rise to the ozone layer (altitude of 10-40 miles with the heaviest concentration, 5 ppm, at 15 miles). It is feared that these fluorocarbon gases break down by strong ultraviolet radiation and then react with the ozone layer and will reduce this protective layer as much as 10% by 1985 to 1990. Since this protective ozone layer absorbs energetic UV radiation and thus protects life from excessive radiation damage, destruction of this layer has potential disastrous effects for life on earth.
The Subcommittee on Public Health and Environment in the U.S. House of Representatives held hearings on the threat to the protective ozone layer of fluorocarbon gases in December 1974 in consideration of a bill, HR. 17577, which could lead to a ban on aerosol sprays containing fluorocarbon gases. This bill was introduced by U.S. Representatives M. L. Esch (R-Mich.) and Paul G. Rogers (D-Fla.), chairman of the Subcommittee. Testifying before the Subcommittee, Ralph J. Cicerone, associate research scientist in the Space Physics Research Laboratory at the University of Michigan and author of a research report (Science, September 27,1974) which brought this problem to public attention, says that claims that "natural processes" would destroy the fluorocarbon gases before they reach the ozone shield "have been dismissed with evidence." He said all recent papers on the subject substantiate the seriousness of the problem. He outlined five research projects aimed at determining the danger of the threat in a short period of time.
William Driver, president of the Manufacturing Chemists Assoc. (MCA), in a letter (which was released to the press) to Chairman Rogers of the Subcommittee, pointed to some of the developments that led to the discovery of fluorocarbons in the atmosphere and outlined past and future fluorocarbon research projects sponsored by MCA. The MCA-sponsored research is supported by all six U.S. producers of fluorocarbon propellants and refrigerants, plus 13 groups based in other countries. Research is under
Editors' Column
way at the University of Reading (England), the University of California (Riverside), and the University of Montreal. The impetus for MCA's fluorocarbon research efforts as delineated by Mr. Driver in his letter is worth quoting:
"In the early 1960's Dr. James E. Lovelock, University of Reading (England), invented a new technique for direct measurement of certain chemical compounds. In the late 1960's he refined this technique to the point where it became possible to measure certain trace component gases in the atmosphere. By 1970, for the first time, if was possible to measure the amounts of simple organic molecules such as carbon tetrachloride, trichlo-roethane, and fluorocarbon compounds in the atmosphere."
Dr. Lovelock's early measurements of trichlorofluoromethane (fluorocarbon 11) and carbon tetrachloride led to his suggestion that carbon tetrachloride had some natural origin and that fluorocarbon 11 profiles were consistent with its man-made origin.
The role of analytical chemistry in MCA's current fluorocarbon gas research program is readily apparent by summing their goals:
• "Continued measurement of fluorocarbon concentrations in the lower atmosphere to determine the rate of accumulation, the rate of diffusion into southern latitudes, and the rate of diffusion into the stratosphere
• "Evaluation of potential removal mechanisms for fluorocarbon compounds in the troposphere
• "Determination of possible chemical reactions of fluorocarbons and chlorine with active species which may exist in the high troposphere or in the stratosphere
• "Direct measurement of as many stable chlorine-bearing species in the troposphere and stratosphere as possible
• "Development of analytical methods for determination of chlorine oxide radical (CIO)
• "Direct measurement of chlorine oxide radical (CIO) in the stratosphere between 50,000 and 100,000 feet."
Thus, developments in analytical chemistry made possible the discovery of fluorocarbons in the atmosphere, and hopefully, developments in analytical chemistry will play a key part in resolving the ensuing questions on the dangers posed by these fluorocarbon gases.
Josephine Petruzzi
SCIENTISTS Do you encounter diff iculties in handling 3 H and/or 1 4 C labeled sample materials for Liquid Scint i l lat ion Counting? or is your equipment outdated? or don't you possess the necessary equipment? or are you simply dissatisfied wi th the data results? or are the expenses involved too high?
Then it is t ime to have a closer look at PEMLAB and its services. We process (preparation-counting-data reduction) t r i t ium and/or carbon-14 labeled materials such as: adipocere — bacteria — bladder — bone — brain — crude oil — egg shell — fat — feces — fur — gels — glands — hair — heart — insects — intestines — kidney — liver — lung — mi II i pore filters — muscle — plant tissue — plasma — plastics — skin — soil — spleen — thin layer scrapes — toluene — urine — water — whole blood — wool — etc., etc.
A major breakthrough in Sample Preparation now utilized at PEMLAB. No worries about: Sample throughput — Sample size — Low specific activity — Sample handling — Unnecessary experimental errors — Down time of the equipment — turnover t ime — error inducing facts in double labeled experiments (we separate the isotopes before counting.)
Unique T R I A L offer and fabulous
quantity discounts.
For more information, please
contact: Peter Mertens, Jr. PEMLAB CO.
8826 Ogden Ave.
Brookfield, III. 60513
(312) 485-3316
Preparation * Counting * Data Reduction
Try It Before You Buy It.
*
TRAINING WORKSHOPS
L E C T U R E S
CIRCLE 193 ON READER SERVICE CARD
ANALYTICAL CHEMISTRY, VOL. 47, NO. 3, MARCH 1975 · 361 A
