Science / Medicine : Chlorofluorocarbon’s danger to the atmosphere has industry scrambling to replace the chemicals that are : Friends to Man, Enemies to Earth
Drink some cool milk for breakfast, take off for work and blast the air conditioner, type away at your computer and then take a quick break for a hamburger at the local fast food joint. Come home and take a nap on the soft cushioned couch.
Chances are you weren’t aware, but each of those actions couldn’t have happened without one essential class of chemicals. And those chemicals are endangering the health of the planet.
Chlorofluorocarbons, or CFCs as they are called, have carved an essential niche for themselves in modern life. As coolants in refrigerators and air conditioning systems, as cleaning fluids for the electronics industry, as insulating materials in Styrofoam packaging, as rigid and flexible foam for cushions and home insulation, CFCs have become an increasingly large part of our everyday lives.
Industry is trying to shift this dependence to other substances, however, because CFCs are escaping into the upper atmosphere, known as the stratosphere, and eating away at the ozone layer. And the ozone is essential for protecting the earth from the damaging ultraviolet rays of the sun.
The shift is bringing with it an unprecedented, wide-ranging search for alternatives to CFCs.
CFCs were used as propellants in aerosol cans until 1978, when they were banned in the United States. At that time, scientists were just beginning to realize that the chemicals were destroying the ozone layer in the stratosphere.
By eliminating propellants alone, it was easy to make a large dent in consumption because propellants encompassed 50% of the market. Once aerosols went out the door, however, a host of other applications came in. Ten years later, CFCs are being produced at levels exceeding the pre-1978 ban.
While CFC production has increased, the evidence incriminating the chemicals has also grown. In September, 1987, several nations convened to draw up an agreement limiting the use of CFCs. It states that participants must make a 20% cut in production by 1993 and a 50% reduction by 1998. To date, 46 countries have signed this document, known as the Montreal Protocol.
The Montreal Protocol sparked a flurry of activity in industry.
E. I. du Pont de Nemours and Co., one of the largest CFC producers, announced it would begin phasing out CFC production. The food packaging industry said it would abandon CFCs, which it uses to insulate Styrofoam containers for fast food, eggs, meat and other products.
In order to meet these deadlines, scientists are racing the clock to develop alternatives. An international group of 14 manufacturers of CFCs joined to carry out toxicity testing on leading candidates. They hope to speed the process by working together, aiming to make the new products available by the mid 1990s.
“We’re all optimistic that these products are coming along very quickly,” said Stephen Andersen of the Environmental Protection Agency. There is consensus among industry representatives, however, that no single product will replace CFCs. “We feel that it’s going to require more than one material to replace all of our . . . needs,” said John Fisher of AT&T; Bell Labs in Princeton, N.J.
Several proposed alternatives are similar to existing CFCs with slight modifications to the chemical structure. Adding a hydrogen atom, for example, makes the compound less stable, so it breaks down before it reaches the upper atmosphere.
Du Pont has begun marketing one such alternative for the food packaging industry. Because of the added hydrogen, Formacel (HCFC 22) has 95% less ozone depletion potential than CFC 12, the substance it replaces. The Food Service Packaging Institute has just switched over to the substitute.
Also on the horizon is a replacement for refrigeration and cooling systems. The most promising substance, HFC 134a, is undergoing toxicity testing, which will take about five years to complete.
Since 134a and most of the other alternatives operate at different temperatures and pressures than their original counterpart, equipment must be modified to accommodate them. As long as the equipment is functioning, coolants are sealed within its system. Only when a unit begins to break down do the CFCs leak and escape into the atmosphere.
At that point, large commercial units like refrigerators, freezers and office air-conditioners can be retrofitted to accommodate alternative compounds, according to Kathleen Forte, senior public affairs specialist at Du Pont in Wilmington, Del.
It makes economic sense to replace, rather than retrofit, such smaller appliances as home refrigerators, Forte said. Prices for new refrigerators equipped with non-CFCs should not be much higher than for those using CFC, Forte said. An average home-size unit only needs six ounces of refrigerant, which today costs less than a dollar. Although Du Pont projects the CFC substitute, 134a, will cost two to five times more, it will have little effect on the price of the refrigerator.
The cost increase will be much more obvious for commercial applications. An air-conditioner installed in a 150,000-square-foot office building requires 1,500 pounds of coolant. A doubling of the cost of the coolant will raise the price of the system considerably.
The expense associated with new equipment applies also to the electronics industry. The new compounds developed for cleaning electronic parts and circuit boards require special machinery for dispensing the cleaning agent. Existing machines cannot accommodate the different properties of the new products.
One of those new compounds, which AT&T; has been using since 1986, was developed by Petroferm, a small company in Fernandina Beach, Fla. BIOACT EC-7 is based on a completely different approach than other substitutes. The chemical, derived from citrus rinds and coniferous trees, bears no resemblance in its chemical structure to CFCs.
Fisher from AT&T; said the company hopes eventually to use BIOACT EC-7 for 20% to 30% of its needs. It has limitations, however. The components must be rinsed with water, and not all parts can be immersed in water.
IBM is also experimenting with a new method for cleaning small mechanical parts for computers.
“It’s not a revolutionary new alternative,” said Ray Kerby, director of environmental programs at IBM in San Jose. The procedure uses a mixture of water and a soapy substance along with ultrasonic vibration.
Kerby said the IBM researchers have spent the last couple of years on technical work, “sharpening up its applicability to our particular cleaning.” They are working with mechanical parts, which must be spotless to function properly. “Even a fingerprint can be a mess,” Kerby said. “Absolute cleanliness is super important.”
David Wirth, senior attorney at the Natural Resources Defense Council, advocates cutting nonessential uses. “The nonessential uses should be the first ones to go,” Wirth said. “There are still a large number of them out there.” They include egg cartons and fast-food packaging, which could be made of other substances, such as cardboard.
In addition to cutting nonessential uses, other avenues exist for bypassing the use of new chemicals. CFCs are extremely volatile.
Containing CFCs in a closed unit or under a hood during cleaning may help. In the past CFCs have been routinely vented into the atmosphere when auto air-conditioners are recharged. Producers are encouraging users to contain the compounds during this process. Also, the chemicals can be recycled rather than disposed of after each use.
Representatives from industry, regulatory agencies and public interest groups have voiced optimism that the deadlines outlined by the Montreal Protocol can be met. But Fisher of AT&T; expressed caution about focusing too heavily on specific deadlines and guidelines.
“I don’t think we should be shooting for a 50% reduction by the year 1998. I think we should really be trying to eliminate CFC usage altogether. Anyone shooting for just a 50% reduction is missing the boat. I think we ought to be trying to eliminate CFCs . . . wherever we can.”
