Empa Investigates Emissions of Greenhouse Gas HFC-23

Researchers from the Swiss Federal Laboratories for Materials Science and Technology(Empa), together with the University of Bristol and the Netherlands Organization for Applied Scientific Research (TNO), have analysed the emissions of the greenhouse gas trifluoromethane (HFC-23). HFC-23 is produced during the production of Teflon and certain coolants. More than 150 countries have committed themselves to the global containment of HFC-23 in the Kigali Amendment to the Montreal Protocol. According to a press release, although the desired containment measures are having an effect, they have not yet been consistently implemented everywhere.

Theoretically, global emissions of HFC-23 in 2020 amounted to only 2,000 tons, but 16,000 tons of the gas were actually released into the atmosphere. For comparison: the greenhouse effect of one kilogram of HFC-23 corresponds to 12,000 kilograms of carbon dioxide. In order to analyze the emissions of a Dutch factory in detail, the team used so-called tracers. This is a non-toxic gas that can be used to determine the concentration of HFC-23 in the atmosphere.

"Since we knew exactly how much tracer we had released and how much of it arrived at the measuring point, we were able to calculate the emissions of HFC-23 and other gases," Dominique Rust, who worked on this project as part of her doctorate at Empa, is quoted as saying in the press release. "Our measured emissions are higher than those reported by the factory," says Martin Vollmer from Empa's Air Pollutants / Environmental Technology department based in Dübendorf. "However, the amount of HFC-23 emitted is still low. The measures to curb emissions are therefore working well."

The high measured values in the atmosphere suggest that HFC-23 emissions from Teflon and coolant manufacturers are higher than reported. The team is therefore calling on countries to have the relevant factories independently inspected. The tracer method they have developed would be suitable for such independent checks. The results have been published in the scientific journal "Nature". ce/eb