The decomposition products of synthetic refrigerants could pose a grave long-term threat to the environment, according to Dr. Ernst Furrer, chemist at the Swiss Environment Agency. He therefore urges policy makers and the industry to promote natural refrigerants as a sustainable alternative.
The use of HFC-134a and other synthetic refrigerants may cause more serious environmental damage than previously thought. Trifluoroacetic acid (TFA), a decomposition product of R134a, will thus be leached out from the atmosphere by the rain, developing a herbicide effect capable of posing an incalculable risk to plants and other organisms. As a consequence, a worldwide rising use of R134 will also accelerate the concentration of the strong organic acid TFA in the nature where it will remain stable over a long period due to its low decomposition potential. The effects this will have on the earth’s eco system are still unknown as the eco-toxicological potential of TFA has only been evaluated to a small extent.
Similarly critical composition products may also be found for other chemical refrigerants, Dr. Ernst Furrer, chemist at the Swiss Environment Agency, concludes in a specialized magazine for the refrigeration industry. A “negligent” use of highly specialized stable gases, whose composition products have not been thoroughly investigated yet, would therefore “play at the expense of the very basis of human existence,” according to Furrer.
According to chemical makers DuPont and Honeywell, TFA will also develop from HFO-1234yf, proposed as a possible alternative for Mobile Air Conditioning.* Similar to the finding that non-ozone depleting substances still accelerated global warming, science could thus discover only years after a wider use of this refrigerant that it may cause losses in biodiversity. Even if TFA does not develop from HFO-1234y, Dr. Furrer still remains sceptical: “It can be expected that through the photolysis of the intermediary decomposition products, hydofluoric acid (HF) will develop. This was discovered for the isomeric compound HFO-1234ze (trans-CF3CF=CHF). That HF is just as problematic for the environment, is without controversy, “Furrer told R744.com.**
Risks of natural refrigerants heavily overstated
As a clear alternative to HFCs, Furrer strongly recommends the use of natural refrigerants, including CO
2, in refrigeration and heat pump applications. Having compared the eco balance – a life cycle approach taking into account all ecological effects from refrigerant manufacturing, use and disposal – of heat pumps using HFC and natural refrigerants, the latter led to “recognizable to significant environmental benefits” at similar energy efficiency. Furrer therefore urges the heating and cooling industry to limit the use of HFCs to essential applications and avoid developing new HFC systems altogether. Instead, international test have already proved that natural refrigerants are a safe and cost-efficient alternative in industrial refrigeration. Their safety risks, such as toxicity, would be especially overstated by multinationals producing chemical refrigerants. In reality, a professional installation and maintenance could handle potential safety risks, while a good planning process would avoid them altogether.
Background
Herbicides are widely used in agriculture to kill unwanted plants while leaving the desired crop unharmed. Although most are said to be safe for humans and mammals, some herbicides can cause a variety of serious health effects, including mutations and cancer. Most impact, however, can be expected on ecological systems, including biodiversity.
* See joint presentation Honeywell/DuPont, 27 Nov 2007: “HFO-1234yf - A Low GWP Refrigerant For MAC”; page 3: “Atmospheric breakdown products are the same as for 134a” (http://refrigerants.dupont.com/Suva/en_US/pdf/DP_HW_2nd_European_Workshop_MAC.pdf)
** Food and Agriculture Organization of the United Nations, 1983: “The great chemical activity of hydrofluoric acid, which is formed by both solid and gaseous fluoride, is responsible for a high acidification of the soil and for the destruction of clay minerals and humic mineral complexes.” (http://www.fao.org/docrep/q2570e/q2570e01.htm#chemical%20stress%20on%20the%20biosphere)
