Prof. Keith Solomon, Centre for Toxicology School of Environmental Sciences at the University of Guelph Canada, gave a talk on "TFA and its salts in the atmosphere". Keith directs an active program of research into the fate and effects of pesticides and other substances in the environment, exposure of humans to pesticides and industrial chemicals, and risk assessment and has more than 42 years’ experience in this field. Keith is also a co-author of UNEP Environmental Effects Assessment Panel (EEAP) reports including its Summary Update 2020 for Policymakers. This summarised these scientific conclusions for TFA: The current low concentration of trifluoroacetic acid (TFA) produced by the degradation of several hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs), is currently judged not to pose a risk to human health or to the environment. Trifluoroacetic acid continues to be found in the environment, including in remote regions, although concentrations are currently very unlikely to have adverse toxicological consequences for humans and ecosystems. While TFA is formed from the HFCs and HFOs regulated under the Montreal Protocol, a large amount of TFA was naturally formed over millions of years and has accumulated in the oceans. An unknown amount originates from fugitive emissions from chemical manufacture, waste disposal sites, laboratory use, and degradation of pharmaceuticals, pesticides, and industrial chemicals containing the trifluoromethyl group.
Prof. A.R. Ravishankara, Colorado State University, gave a talk on "TFA from use of HFO1234yf in mobile air-conditioning (MAC)". Prof. Ravishankara has worked over the four decades on the chemistry of the Earth’s atmosphere as it relates to stratospheric ozone depletion, climate change, and regional air quality. His measurements in the laboratory and in the atmosphere have contributed to deciphering the ozone layer depletion, including the ozone hole; to identifying environmentally acceptable substitutes for ozone-depleting substance; to quantifying the role of chemically active species on climate; and to advancing the understanding of the formation, removal, and properties of pollutants. The talk presented the results of an important new study that investigated trifluoroacetic acid (TFA) formation from emissions of HFO-1234yf, its dry and wet deposition, and rainwater concentration over India, China, and the Middle East. The study concluded that the ecological and human health impacts now and from continued use of HFO-1234yf in India, China, and the Middle East are estimated to be insignificant. See EFCTC newsletter item from November 2021 for more information about this study.
The EFCTC welcomes a factual, scientifically based discussion on the environmental impact of refrigerants and their use in refrigeration systems. The lively discussion that took place during the DKV session shows how emotionally charged the topic is and how much a factual discussion considering scientific findings is needed. The EFCTC is ready for this discussion.