TEXTE 73/2021 German Environment Agency Final report Persistent degradation products of halogenated refrigerants and blowing agents in the environment: type, environmental concentrations, and fate with particular regard to new halogenated substitutes with low global warming potential by: Dr. David Behringer, Dr. Felix Heydel, Barbara Gschrey, Steffi Osterheld, Winfried Schwarz, Kristina Warncke Öko-Recherche, Frankfurt am Main Finnian Freeling, Dr. Karsten Nödler Technologiezentrum Wasser (TZW), Karlsruhe Dr. Stephan Henne, Dr. Stefan Reimann Empa, Dübendorf (Zürich) Markus Blepp, Wolfram Jörß, Ran Liu, Dr. Sylvie Ludig, Ina Rüdenauer Öko-Institut, Freiburg im Breisgau Dr. Stefan Gartiser Hydrotox Labor für Ökotoxikologie und Gewässerschutz GmbH, Freiburg im Breisgau publisher: German Environment Agency TEXTE 73/2021 Ressortforschungsplan of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety Project No. (FKZ) 3717 41 305 0 Report No. FB000452/ENG Final report Persistent degradation products of halogenated refrigerants and blowing agents in the environment: type, environmental concentrations, and fate with particular regard to new halogenated substitutes with low global warming potential by Dr. David Behringer, Dr. Felix Heydel, Barbara Gschrey, Steffi Osterheld, Winfried Schwarz, Kristina Warncke Öko-Recherche, Frankfurt am Main Finnian Freeling, Dr. Karsten Nödler Technologiezentrum Wasser (TZW), Karlsruhe Dr. Stephan Henne, Dr. Stefan Reimann Empa, Dübendorf (Zürich) Markus Blepp, Wolfram Jörß, Ran Liu, Dr. Sylvie Ludig, Ina Rüdenauer Öko-Institut, Freiburg im Breisgau Dr. Stefan Gartiser Hydrotox Labor für Ökotoxikologie und Gewässerschutz GmbH, Freiburg im Breisgau On behalf of the German Environment Agency Imprint Publisher Umweltbundesamt Wörlitzer Platz 1 06844 Dessau-Roßlau Tel: +49 340-2103-0 Fax: +49 340-2103-2285 buergerservice@uba.de Internet: www.umweltbundesamt.de /umweltbundesamt.de /umweltbundesamt Report performed by: Öko-Recherche - Büro für Umweltforschung und -beratung GmbH Münchener Str. 23a 60329 Frankfurt/Main Germany Report completed in: September 2020 Edited by: Section III 1.4 Substance-related Product Issues Gabriele Hoffmann (Fachbegleitung) Publication as pdf: http://www.umweltbundesamt.de/publikationen ISSN 1862-4804 Dessau-Roßlau, May 2021 The responsibility for the content of this publication lies with the author(s). mailto:buergerservice@uba.de file://host2/Daten/.kunde/uba.de/UBA_Word_Anpassung/Vorlagen_englisch/www.umweltbundesamt.de http://www.umweltbundesamt.de/publikationen UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 4 Abstract This report describes the current status and the development of the use and emissions of halogenated refrigerants, foam blowing agents and aerosol propellants in Germany and in the EU. The focus is on hydrofluorocarbons (HFCs) and unsaturated hydrofluorocarbons with low global warming potential (u-HFCs and u-HCFCs) and their atmospheric degradation products. In addition to hydrogen fluoride, trifluoroacetic acid (TFA) or trifluoroacetate have been identified as persistent degradation products of some halogenated refrigerants foam blowing agents and aerosol propellants. The demand, the emis- sions, and the amount of degradation products of halogenated refrigerants, foam blowing agents and aerosol propellants were modelled in a scenario with maximal future use and emissions of unsaturated halogenated substances up to the year 2050. The projections show that in the future, especially the emissions of the refrigerant u-HFC-1234yf from mobile and stationary air conditioning will add a large additional share to the amounts of TFA or trifluoroacetate in the atmosphere. In order to quantify the atmospheric input of trifluoroacetate via precipitation, a two-year nationwide measurement pro- gramme was carried out in Germany for the first time, from February 2018 to March 2020. Compared with earlier measurements in the context of other projects, significantly higher concentrations of tri- fluoroacetate were found in rainwater. Based on the projections and the results of the measurement programme, the expected maximal input of TFA or trifluoroacetate from the atmospheric degradation of halogenated refrigerants, foam blowing agents and aerosol propellants in Germany and the EU were calculated. The use of halogenated substitutes with a low global warming potential must be regarded as problem- atic in view of the persistence of TFA or trifluoroacetate in the environment. TFA or trifluoroacetate inputs into groundwater and drinking water can only be removed with considerable effort. Therefore, fluorinated refrigerants, foam blowing agents and aerosol propellants should be replaced by more sus- tainable solutions with halogen-free substances. Kurzbeschreibung Dieser Bericht beschreibt den Ist-Zustand und die Entwicklung der Verwendung und der Emissionen halogenierter Kälte- und Treibmittel in Deutschland und in der EU. Der Fokus liegt auf teilfluorierten Fluorkohlenwasserstoffen (HFKW) und ungesättigten halogenierten Kohlenwasserstoffen mit kleinem Treibhauspotential (u-HFKW und u-HFCKW) sowie deren atmosphärischen Abbauprodukten. Neben Fluorwasserstoff wurde insbesondere Trifluoressigsäure (TFA) bzw. Trifluoracetat als persistentes Ab- bauprodukt einiger halogenierter Kälte- und Treibmittel identifiziert. Der Bedarf, die Emissionen und die Menge der Abbauprodukte von halogenierten Kälte- und Treibmitteln wurden bis zum Jahr 2050 in einem Szenario mit maximaler zukünftiger Verwendung und Emission ungesättigter halogenierter Stoffe modelliert. Die Projektionen zeigen, dass zukünftig insbesondere die Emissionen des Kältemittels u-HFKW-1234yf aus der mobilen und stationären Klimatisierung einen hohen zusätzlichen Anteil zu den TFA- bzw. Trifluoracetat-Mengen in der Atmosphäre beitragen werden. Um den atmosphärischen Eintrag von Trifluoracetat über den Niederschlag zu quantifizieren, wurde erstmalig ein zweijähriges deutschlandweites Messprogramm von Februar 2018 bis März 2020 durchgeführt. Im Vergleich zu früheren Messungen im Rahmen anderer Projekte ergaben sich deutlich erhöhte Konzentrationen von Trifluoracetat im Regenwasser. Basierend auf den Projektionen und den Ergebnissen des Messpro- gramms konnte der zu erwartende maximale Eintrag von TFA bzw. Trifluoracetat aus dem atmosphäri- schen Abbau halogenierter Kälte- und Treibmittel in Deutschland und der EU abgeschätzt werden. Die Verwendung von halogenierten Ersatzstoffen mit kleinem Treibhauspotential ist angesichts der Per- sistenz von TFA bzw. Trifluoracetat in der Umwelt als problematisch anzusehen. TFA bzw. Triflu- oracetat-Einträge in Grund- und Trinkwasser können nur mit erheblichem Aufwand wieder entfernt werden. Daher sollten fluorierte Kälte- und Treibmittel durch nachhaltigere Lösungen mit halogen- freien Stoffen ersetzt werden. UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 5 Table of contents Table of contents .............................................................................................................................................. 5 List of figures Summary .................................................................................................................................... 9 List of tables Summary ................................................................................................................................... 11 Abbildungsverzeichnis Zusammenfassung ..................................................................................................... 12 Tabellenverzeichnis Zusammenfassung ......................................................................................................... 14 List of figures .................................................................................................................................................. 15 List of tables .................................................................................................................................................... 21 List of figures Annex ....................................................................................................................................... 26 List of tables Annex ........................................................................................................................................ 28 List of abbreviations ....................................................................................................................................... 29 Summary ......................................................................................................................................................... 32 Zusammenfassung .......................................................................................................................................... 48 1 Introduction .......................................................................................................................................... 65 1.1 Halogenated greenhouse gases with potential to form persistent degradation products in the atmosphere ................................................................................................. 65 1.2 The progression from fully halogenated CFCs to u-HFCs and u-HCFCs ................................ 65 1.3 Unsaturated HFCs as substitutes for saturated HFCs ........................................................... 66 1.4 Atmospheric degradation products of halogenated refrigerants and blowing agents .................................................................................................................................... 69 1.5 Objective of this project ....................................................................................................... 69 2 Analysis of the current situation ........................................................................................................... 71 2.1 Objective ............................................................................................................................... 71 2.2 Methods ................................................................................................................................ 72 2.2.1 Use and emissions of fluorinated gases ........................................................................... 72 2.2.2 Scientific Literature .......................................................................................................... 72 2.2.3 Other sources ................................................................................................................... 74 2.2.4 Expert surveys .................................................................................................................. 74 2.3 Identification of relevant substances ................................................................................... 75 2.4 Production of halogenates refrigerants and foaming agents ............................................... 77 2.4.1 Production routes and emissions of HFCs produced in the EU ....................................... 78 2.4.2 Production routes and emissions of u-HFCs and u-HCFCs ............................................... 80 2.4.3 Fugitive emissions from the production of halogenated refrigerants and blowing agents ................................................................................................................. 82 2.4.4 Minor components in halogenated refrigerants and blowing agents ............................. 83 2.5 Use of halogenated refrigerants and blowing agents .......................................................... 84 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 6 2.5.1 Application quantities of halogenated refrigerants and blowing agents ........................ 84 2.5.2 Emissions of halogenated refrigerants and blowing agents ............................................ 90 2.5.3 Emissions from the production of u-HFC-containing products in Germany .................... 92 2.5.4 Niche applications of u-HFCs and u-HCFCs ...................................................................... 93 2.6 Destruction of halogenated refrigerants and blowing agents .............................................. 96 2.6.1 Unintentional destruction ................................................................................................ 96 2.6.2 Disposal of equipment and devices ................................................................................. 98 2.7 Atmospheric degradation products of halogenated refrigerants and blowing agents .................................................................................................................................... 98 2.7.1 Initiation of degradation .................................................................................................. 98 2.7.2 Formation of intermediates ........................................................................................... 100 2.7.3 Atmospheric degradation of the halogenated intermediates ....................................... 103 2.7.4 Substance-specific TFA formation rates ......................................................................... 109 2.8 Other relevant halogenated substances forming TFA ........................................................ 112 2.9 Trifluoroacetic acid (TFA) and trifluoroacetate in the environment .................................. 115 2.9.1 Input path of trifluoroacetic acid (TFA) into the environment ...................................... 115 2.9.2 Natural TFA sources ....................................................................................................... 120 2.9.3 Further reactions of trifluoroacetic acid (TFA) in the atmosphere ................................ 121 2.10 Biodegradability and ecotoxicity of halogenated low-GWP refrigerants and blowing agents and their persistent atmospheric degradation products ........................................ 123 2.10.1 Halogenated refrigerants and blowing agents with small GWP .................................... 123 2.10.2 Trifluoroacetic acid (TFA) ............................................................................................... 127 3 Projections of halogenated refrigerants and blowing agents until the year 2050 ............................. 131 3.1 Objectives ........................................................................................................................... 131 3.2 Method description ............................................................................................................ 132 3.2.1 Description of the model and its further development ................................................. 132 3.2.2 Conversion of emissions of relevant substances into TFA quantities ............................ 137 3.2.3 Conversion of emissions of relevant substances into quantities of hydrogen fluoride .......................................................................................................................... 138 3.3 Assumptions for a u-HFC and u-HCFC maximum scenario until 2050 ................................ 138 3.3.1 Legal and political guidelines ......................................................................................... 138 3.3.2 Database for Germany ................................................................................................... 139 3.3.3 Assumptions for Europe (EU-28) .................................................................................... 139 3.4 Results of projections on demand, emissions, and degradation products ........................ 142 3.4.1 Demand and emission quantities of HCFCs, HFCs, u-HFCs and u-HCFCs in the EU-28 until the year 2050 .............................................................................................. 142 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 7 3.4.2 Validation of the projections .......................................................................................... 148 3.4.3 Emissions of important TFA precursor substances and TFA quantities formed ............ 152 3.4.4 Emission of halogenated greenhouse gases and formed quantities of hydrogen fluoride for Europe (EU-28) ........................................................................................... 158 3.5 Flow Analysis for Europe (EU-28) for the year 2030 ........................................................... 161 3.6 Limitations of the AnaFgas model ...................................................................................... 163 3.6.1 Selection of projected substances ................................................................................. 163 3.6.2 Limits of the assumptions .............................................................................................. 163 4 Field monitoring campaign to determine the wet deposition of trifluoroacetic acid (TFA)/trifluoroacetate ......................................................................................................................... 165 4.1 Objectives ........................................................................................................................... 165 4.2 General Information ........................................................................................................... 165 4.3 Sampling of precipitation, soil, and plant material............................................................. 165 4.3.1 Precipitation sampling.................................................................................................... 167 4.3.2 Sampling of soil and plant material ................................................................................ 168 4.4 Methods for trifluoroacetate analysis ................................................................................ 169 4.4.1 Analysis of precipitation samples ................................................................................... 169 4.4.2 Analysis of soil and plant samples .................................................................................. 169 4.5 Results ................................................................................................................................. 171 4.5.1 Trifluoroacetate in precipitation .................................................................................... 171 4.5.2 Results from the analysis of soil and plant samples ...................................................... 185 5 Overall evaluation ............................................................................................................................... 188 5.1 Objective ............................................................................................................................. 188 5.2 Estimation of the contribution of atmospheric degradation of HCFCs, HFCs and u- HFC-1234yf to the observed deposition of trifluoroacetic acid (TFA) ................................ 188 5.2.1 Methodology .................................................................................................................. 188 5.2.2 Results ............................................................................................................................ 193 5.3 Allocation of u-HFC and u-HCFC observations by air mass origin at Taunus Observatory ........................................................................................................................ 202 5.3.1 Methodology .................................................................................................................. 202 5.3.2 Results ............................................................................................................................ 203 5.4 Comparison of the trifluoroacetate rainwater measurements with the literature ........... 206 5.5 Development of emissions and deposition of trifluoroacetic acid (TFA) ........................... 210 5.6 Outlook ............................................................................................................................... 211 5.7 Further need for research ................................................................................................... 213 6 References .......................................................................................................................................... 214 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 8 A. Annex .................................................................................................................................................. 224 A.1 Literature used on biodegradability and environmental toxicity ....................................... 224 A.2 Internet research on niche applications ............................................................................. 225 A.3 Documentation of the expert discussions carried out ....................................................... 226 A.3.1 Questionnaire template for the expert discussions – industry version ......................... 226 A.3.2 Questionnaire template for the expert discussions – science version .......................... 226 A.4 Attended events ................................................................................................................. 228 A.5 Summary of patented production routes for the manufacture of some u-HFCs and u-HCFCs ............................................................................................................................... 228 A.6 List of product names in niche applications ....................................................................... 229 A.7 List of TFA-forming halogenated refrigerants and blowing agents .................................... 232 A.8 Annex on biodegradability and ecotoxicity ........................................................................ 233 A.9 Annex to the projections in Chapter 3 ................................................................................ 241 A.10 Annex to the results of the precipitation analysis from Chapter 4 .................................... 247 A.10.1 Materials for rainwater sampling ................................................................................... 247 A.10.2 Sampling protocol for collecting rainwater samples ..................................................... 247 A.10.3 Analysis results ............................................................................................................... 248 A.11 Concentration of HFC-134a in the atmosphere .................................................................. 258 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 9 List of figures Summary Figure S 1: Atmospheric degradation of HFC-134a (left) and u-HFC-1234yf (right) via the fluorinated intermediates trifluoroacetyl fluoride (TFF, CF3CFO), CF3 radicals and HCFO to the terminal fluorinated degradation products trifluoroacetic acid (TFA) and hydrogen fluoride (HF). .................................................................................................... 35 Figure S 2: Demand and emissions of HCFCs (up to 2015), HFCs, u-HFCs and u-HCFCs in Europe (EU-28) in kilotonnes for the period from 2000 until 2050. ........................................................................................... 36 Figure S 3: Trends of European emissions (EU-28) and resulting TFA quantities formed by relevant HFCs, u-HFCs and u-HCFCs used as refrigerants and blowing agents in various applications in kilotonnes in the period from 2000 to 2050. All other projected substances that form TFA are summarized as “Others”. .................................................................... 38 Figure S 4: European (EU-28) emissions of important HFCs, u-HFCs and u-HCFCs in refrigerants and blowing agents, and resulting trifluoroacetic acid (TFA) quantities in kilotonnes by sector for the years 2000 to 2050 in 10-year steps. All other projected TFA-forming substances are summarized as “Others”. The sector “Others” is not shown, as the TFA quantities here are at a maximum of about 0.03 kilotonnes (30 tonnes). ............................................................................................... 39 Figure S 5: Sankey mass flow diagram of the total European (EU-28) emissions of the modelled halogenated substances from use and disposal in the various sectors and the atmospheric degradation products trifluoroacetic acid (TFA) and hydrogen fluoride (HF) for the year 2030. The sectors foam blowing agents, aerosol propellants, solvents, and fire extinguishing agents as well as the semiconductor industry and emissions from HFC production are summarized as “Others”. ... 40 Figure S 6: Locations of the rainwater sampling in Germany; the abbreviations used for each of the stations is indicated in brackets. ....................... 42 Figure S 7: Box plots of the precipitation-weighted trifluoroacetate concentrations of the volume-equivalent monthly composite samples of precipitation from February 2018 (02/18) to February 2020 (02/2020) from seven measuring stations that only collected wet deposition samples. Grouping of data is based on time (month and year). The periods from February to January are separated by colour. The y-axis is shown on a binary logarithmic scale. Station Stuttgart is not included in 02/18. For February 2020 there is only one monthly composite value for the Stuttgart station. ......................................... 43 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 10 Figure S 8: Box plots of the trifluoroacetate deposition over the precipitation from February 2018 (02/18) to February 2020 (analysis of the volume-equivalent monthly composite samples) of all seven measuring stations that only recorded the wet deposition. Grouping of data based on time (month and year). The periods from February to January are separated by colour. The y-axis is shown on a binary logarithmic scale. Station Stuttgart is not included in 02/18. For February 2020 there is only one monthly composite value for the Stuttgart station. ................................................................................. 44 Figure S 9: Estimated future TFA deposition (input in kilotonnes per year) (top) and TFA deposition rates (input in kg/km² per year) (bottom) from the atmospheric degradation of u-HFC-1234yf for Europe (EU-27, Great Britain, Switzerland and Turkey) with surrounding seas (Europe land area + seas), the land area of Europe (Europe land area) and Germany (Germany land area). .......................................................... 46 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 11 List of tables Summary Table S 1: List of unsaturated halogenated refrigerants, foam blowing agents and aerosol propellants with low global warming potential currently commercially available in Europe (EU-28). ......................................... 33 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 12 Abbildungsverzeichnis Zusammenfassung Abbildung S 1: Atmosphärischer Abbau von HFKW-134a (links) und u-HFKW-1234yf (rechts) über die fluorierten Zwischenprodukte Trifluoracetylfluorid (TFF, CF3CFO), CF3-Radikale und HCFO zu den terminalen fluorierten Abbauprodukten Trifluoressigsäure (TFA) und Fluorwasserstoff (HF). ............................................................................................................ 51 Abbildung S 2: Bedarf und Emissionen von HFCKW (bis 2015), HFKW, u-HFKW und u-HFCKW in Europa (EU-28) in Kilotonnen für den Zeitraum der Jahre 2000 bis 2050. ..................................................................................... 52 Abbildung S 3: Entwicklung der europäischen (EU-28) Emissionen und daraus resultierenden Mengen an Trifluoressigsäure (TFA) von wichtigen TFA-bildenden HFKW-, u-HFKW- und u-HFCKW-haltigen Kälte- und Treibmitteln über alle Sektoren in Kilotonnen für die Jahre 2000 bis 2050 in 10-Jahres-Schritten. Alle weiteren projizierten TFA-bildenden Substanzen sind unter der Bezeichnung „Andere“ subsummiert. ..... 54 Abbildung S 4: Europäische (EU-28) Emissionen von wichtigen HFKW-, u-HFKW- und u-HFCKW-in Kälte- und Treibmitteln und daraus gebildete Menge an Trifluoressigsäure (TFA) in Kilotonnen nach Sektor für die Jahre 2000 bis 2050 in 10-Jahres-Schritten. Alle weiteren projizierten TFA-bildenden Substanzen sind unter der Bezeichnung „Andere“ subsummiert. Der Sektor „Weitere“ wird nicht gezeigt, da die TFA- Mengen hier im Maximum bei ca. 0,03 Kilotonnen (30 Tonnen) liegen. TM = Treibmittel, LM = Lösemittel, FLM = Feuerlöschmittel. . 55 Abbildung S 5: Sankey-Mengenflussdiagramm der europäischen (EU-28) Gesamtemissionen der modellierten halogenierten Stoffe aus der Verwendung und Entsorgung in den verschiedenen Sektoren und die atmosphärischen Abbauprodukte Trifluoressigsäure (TFA) und Fluorwasserstoff (HF) für das Jahr 2030. Die Sektoren Schäume, Treib-, Lösungs- und Feuerlöschmittel sowie Halbleiterindustrie und Emissionen aus der HFKW Produktion sind unter „Weitere“ subsumiert. ......................................................................................... 56 Abbildung S 6: Standorte der Niederschlagsprobenahme; im weiteren Verlauf verwendete Kürzel der Stationen in Klammern. ................................ 58 Abbildung S 7: Boxplots der niederschlagsgewichteten Trifluoracetat- Konzentrationen der volumenäquivalenten Monatsmischproben des Niederschlags von Februar 2018 (02/18) bis Februar 2020 (02/2020) von sieben Messstationen, die ausschließlich die nasse Deposition erfassen haben. Gruppierung der Daten anhand der Zeit (Monat und Jahr). Die Zeiträume Februar bis Januar sind farblich getrennt. Die y- Achse ist binär logarithmisch skaliert. Station Stuttgart ist nicht in 02/18 enthalten. Für Februar 2020 gibt es nur einen Monatsmischwert für die Station Stuttgart........................................ 59 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 13 Abbildung S 8: Boxplots der Trifluoracetat-Einträge über den Niederschlag von Februar 2018 (02/18) bis Februar 2020 (Analyse der volumenäquivalenten Monatsmischproben) aller sieben Messstationen, die ausschließlich die nasse Deposition erfasst haben. Gruppierung der Daten anhand der Zeit (Monat und Jahr). Die Zeiträume Februar bis Januar sind farblich getrennt. Die y-Achse ist binär logarithmisch skaliert. Station Stuttgart ist nicht in 02/18 enthalten. Für Februar 2020 gibt es nur einen Monatsmischwert für die Station Stuttgart. .......................................................................... 60 Abbildung S 9: Abgeschätzte zukünftige TFA-Deposition (Eintrag in Kilotonnen pro Jahr) (oben) bzw. TFA-Depositionsraten (Eintrag in kg/km² pro Jahr) (unten) aus dem atmosphärischen Abbau von u-HFKW-1234yf für Europa (EU-28, Norwegen, Schweiz und Türkei) mit umliegenden Meeren (Europa Landfläche + Meere), die Landfläche Europas (Europa Landfläche) und von Deutschland (Deutschland Landfläche). ............................................................................................................ 62 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 14 Tabellenverzeichnis Zusammenfassung Tabelle S 1: Auflistung von derzeit in Europa (EU-28) kommerziell verfügbaren ungesättigten halogenierten Kälte- und Treibmitteln mit kleinem Treibhauspotential.............................................................................. 49 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 15 List of figures Figure 1: Distribution of use volumes of reportable saturated and unsaturated HCFCs and HFCs in Germany (DE) and the EU-28 for 2018. ............... 84 Figure 2: The initial degradation of saturated HCFCs and HFCs (haloalkanes, e.g. HFC-134a) and unsaturated HFCs and HCFCs (haloalkenes, e.g. u- HFC-1234yf) via reaction with OH radicals in the atmosphere leads to halogenated carbonyl compounds, e.g. formyl fluoride (HCFO) or trifluoroacetyl fluoride (TFF, CF3CFO) ................................................. 99 Figure 3: Simplified degradation scheme for the OH-initiated addition of HFC- 134a. The result is 7-20 % trifluoroacetyl fluoride (TFF, CF3CFO)..... 100 Figure 4: Degradation scheme for the OH-initiated addition of u-HFC-1234yf. The result is exclusively trifluoroacetyl fluoride (TFF, CF3CFO). ....... 101 Figure 5: Degradation scheme for the OH-initiated addition of u-HFC- 1234ze(E). Trifluoroacetaldehyde (CF3CHO) is formed, but not trifluoroacetyl fluoride (TFF, CF3CFO). .............................................. 102 Figure 6: Degradation scheme for the OH-initiated addition of u-HCFC- 1233zd(E). Trifluoroacetaldehyde (CF3CHO) is formed, but not trifluoroacetyl fluoride (TFF, CF3CFO). .............................................. 102 Figure 7: Atmospheric degradation of HFC-134a (left) and u-HFC-1234yf (right) via the fluorinated intermediates trifluoroacetyl fluoride (TFF, CF3CFO), CF3 radicals and HCFO to the terminal fluorinated degradation products trifluoroacetic acid (TFA) and hydrogen fluoride (HF). The degradation pathways are only completely shown here for the halogenated substances. ............................................................ 104 Figure 8: Atmospheric degradation pathway of trifluoroacetaldehyde (CF3CHO) via an OH-initiated abstraction reaction (OH-), hydrolysis (H2O) and photolysis (hν). ................................................................................. 106 Figure 9: Interrelationships for various u-HFCs and u-HCFCs with a hydrogen or fluorine atom on the central carbon atom: Depending on the fluorine or hydrogen atom on the central carbon atom , atmospheric degradation of u-HFCs and u-HCFCs with C3-bodies produces primarily trifluoroacetyl fluoride (TFF) or trifluoroacetaldehyde, which influences the further conversion rate to trifluoroacetic acid (TFA). X stands for F, Cl or H. ............................................................ 110 Figure 10: Simplified illustration of the basic structure of the AnaFgas model for calculating demand and emissions of halogenated HCFCs, HFCs, u- HFCs and u-HCFCs in Europe (EU-28) per sector and gas in metric tons. The actual calculations are highly sector-specific and consider additional factors such as population development in the different EU Member States and technological developments. The first filling refers only to equipment filled in Europe (EU-28). .......................... 133 Figure 11: Applications of HCFCs, HFCs, u-HFCs and u-HCFCs in the AnaFgas model adapted for this purpose; VRF stands for variable refrigerant flow, PU for polyurethane, XPS for extruded polystyrene. .............. 134 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 16 Figure 12: Demand and emissions of HCFCs, HFCs, u-HFCs and u-HCFCs in the EU-28 in metric kilotonnes for the period 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. ..................................................... 143 Figure 13: Quantity of projected demand and emissions of HCFCs, HFCs, u-HFCs and u-HCFCs in Europe (EU-28) in metric kilotonnes (kt) in the years 2000 to 2050 in 10-year increments by sector for the “u-HFC and u-HCFC maximum scenario”. The sector "Others" is not shown because the quantities of demand and emissions over the period 2000 to 2050 average 0.03 kt and 0.45 kt respectively. ................... 146 Figure 14: Demand and emissions of HCFCs, HFCs, u-HFCs and u-HCFCs in Europe (EU-28) in metric kilotonnes in 10-year increments from 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. Only substances that have exceeded an annual demand of 10,000 tonnes or an annual emission of 5,000 tons between 2000 and 2050 are included. ........................................................................................... 148 Figure 15: Comparison of the demand in megatonnes CO2-eq (top) and metric kilotonnes (bottom) of HFCs, u-HFCs and u-HCFCs in Europe (EU-28) from 2007 to 2018 according to the adapted AnaFgas model for the “u-HFC and u-HCFC maximum scenario” and the EU F-gas report (EEA 2019). The reported data have been corrected to ensure comparability with the projected data. ............................................ 149 Figure 16: Comparison of emissions in megatons (Mt) CO2-eq of HFC, u-HFC and u-HCFC in Europe (EU-28) from 2000 to 2017 according to the adapted AnaFgas model for the “u-HFC and u-HCFC maximum scenario” and the “National Inventory Report” (NIR) of the EU-28. 150 Figure 17: Comparison of the projected demand in megatons (Mt) CO2-eq of HFCs, u-HFCs and u-HCFCs in Europe (EU-28) from 2015 to 2050 according to the adjusted AnaFgas model for the “u-HFC and u-HCFC maximum scenario” with the maximum permitted amount for placing on the market (POM) of HFCs in the EU-28 under the EU F-gas Regulation and the maximum permitted consumption of HFCs according to the Kigali Amendment. ................................................ 151 Figure 18: Development of European (EU-28) emissions and resulting quantities of trifluoroacetic acid (TFA) of major TFA-forming HFCs, u-HFCs and u-HCFC-containing refrigerants and blowing agents across all sectors in metric kilotonnes for the years 2000 to 2050 in 10-year steps for the “u-HFC and u-HCFC maximum scenario”. All other projected TFA- forming substances are subsumed under the heading “Others”. .... 154 Figure 19: Quantities of European (EU-28) emissions and formed trifluoroacetic acid (TFA) of major TFA-forming HFC-, u-HFC- and u-HCFC-containing refrigerants and blowing agents in metric kilotonnes by sector for the years 2000 to 2050 in 10-year steps for the “u-HFC and u-HCFC maximum scenario”. All other projected TFA-forming substances are subsumed under the heading "Others". The sector "Others" is not shown, because the TFA amounts here are at a maximum of approx. 0.03 kt. .............................................................................................. 155 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 17 Figure 20: Development of German emissions and resulting amount of trifluoroacetic acid (TFA) of important TFA-forming HFC-, u-HFC- and u-HCFC-containing refrigerants and blowing agents across all sectors in metric kilotonnes for the years 2000 to 2050 in 10-year steps for the “u-HFC and u-HCFC maximum scenario”. All other projected TFA- forming substances are subsumed under the heading “Others”. .... 157 Figure 21: Development of German emissions and resulting amount of trifluoroacetic acid (TFA) of major TFA-forming HFC-, u-HFC- and u- HCFC-containing refrigerants and blowing agents in metric kilotonnes by sector for the years 2000 to 2050 in 10-year steps for the “u-HFC and u-HCFC maximum scenario”. All other projected TFA-forming substances are subsumed under the heading "Others". The sector "Others" is not shown, because the TFA-amounts here are at a maximum of about 0.006 kt. ............................................................ 158 Figure 22: Emissions of all projected HCFC, HFC, u-HFC and u-HCFC containing refrigerants and propellants in Europe (EU-28) and the resulting quantities of hydrogen fluoride (HF) in metric kilotonnes for the years 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. ...... 159 Figure 23: Emissions of TFA-forming HCFC-, HFC-, u-HFC- and u-HCFC-containing refrigerants and propellants in Europe (EU-28) and quantities of trifluoroacetic acid (TFA) and hydrogen fluoride (HF) formed therefrom in metric kilotonnes for the period from 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. .................................. 161 Figure 24: Sankey flow diagram of the European (EU-28) total emissions of modelled halogenated substances from use and disposal in the various sectors and the atmospheric degradation products TFA and HF for the year 2030 for the “u-HFC and u-HCFC maximum scenario”. The sectors foams, propellants, solvents, and fire extinguishing agents, as well as semiconductor industry and emissions from HFC production, are subsumed under „Others”. ..................................... 162 Figure 25: Geographic location and of studied sampling site in Germany. Sampling site abbreviations in parentheses. .................................... 166 Figure 26: Soil profile within the soil sampler. .................................................. 169 Figure 27: Boxplots of the trifluoroacetate concentration of (volume-equivalent) monthly composite precipitation samples from February 2018 (02/18) to February 2020 (02/20). Data of the site Brocken, where the total amount of atmospherically deposited trifluoroacetate instead of the wet deposited trifluoroacetate was determined, are not included. The best-case scenario is shown. Data is grouped by time (month and year). Note that the boxplot of February 2018 (02/18) does not include data from site Stuttgart, whereas the boxplot of February 2020 (02/20) solely represents data from site Stuttgart. The y-axis is on a binary logarithmic scale. The periods February to January are highlighted in different colors. .................. 172 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 18 Figure 28: Boxplots of the trifluoroacetate concentration of (volume-equivalent) monthly composite precipitation samples of studied sites. Data is grouped by the sampling location (site) and sites are plotted in descending median order. Data of the site Brocken, where the total amount of atmospherically deposited trifluoroacetate instead of the wet deposited trifluoroacetate was determined, is included for comparison. The best-case scenario is shown. The y-axis is on a binary logarithmic scale. Note that the boxplot of site Stuttgart includes data from March 2018 to February 2020, whereas boxplots from other sites include data from February 2018 to January 2020. .......................................................................................................... 174 Figure 29: Boxplots of the trifluoroacetate wet-deposition flux of (volume- equivalent) monthly composite precipitation samples from February 2018 (02/18) to February 2020 (02/20). Data of the site Brocken, where the total amount of atmospherically deposited trifluoroacetate instead of the wet deposited trifluoroacetate was determined, are not included. The best-case scenario is shown. Data is grouped by time (month and year). Note that the boxplot of February 2018 (02/18) does not include data from site Stuttgart, whereas the boxplot of February 2020 (02/20) solely represents data from site Stuttgart. The y-axis is on a binary logarithmic scale. The periods February to January are highlighted in different colors. ..... 176 Figure 30: Boxplots of the trifluoroacetate wet-deposition flux of (volume- equivalent) monthly composite precipitation samples of studied sites. Data is grouped by the sampling location (site) and sites are plotted in descending median order. Data of the site Brocken, where the total amount of atmospherically deposited trifluoroacetate instead of the wet deposited trifluoroacetate was determined, is included for comparison. The best-case scenario is shown. The y-axis is on a binary logarithmic scale. Note that the boxplot of site Stuttgart includes data from March 2018 to February 2020, whereas boxplots from other sites include data from February 2018 to January 2020. .......................................................................................................... 178 Figure 31: Median of the trifluoroacetate concentration (in µg/L) and the trifluoroacetate flux (in µg/m²) of the (volume-equivalent) monthly composite samples, as well as the precipitation total (in mm or L/m²) at the eight investigated stations for the periods February 2018 to January 2019 (2028/19) and February 2019 to January 2020 (2019/20). The best-case scenario is shown. For the Stuttgart site, the periods from March to February of the following year are depicted. The site Brocken is not included in the category "all", since the total amount of atmospherically deposited trifluoroacetate instead of only the wet-deposited trifluoroacetate was determined there. ............ 180 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 19 Figure 32: Censored boxplots of trifluoroacetate concentrations present in individual precipitation samples grouped by the sampling site. The best-case scenario is shown. Note that the boxplot of site Stuttgart includes data from March 2018 to February 2019, whereas boxplots from other sites include data from February 2018 to January 2019. Sites are plotted in descending median order. The horizontal red line depicts the detection limit. The y-axis is scaled logarithmically. ..... 183 Figure 33: Boxplots of trifluoroacetate fluxes of individual precipitation samples grouped by the sampling site. The best-case scenario is shown. Note that the boxplot of site Stuttgart includes data from March 2018 to February 2019, whereas boxplots from other sites include data from February 2018 to January 2019. Sites are plotted in descending median order. The y-axis is scaled logarithmically. .......................... 184 Figure 34: Frequency distribution of the atmospheric concentration of u-HFC- 1234yf (in ppt) at the Jungfraujoch (JFJ), Mace Head (MHD), Taunus (TNS) and Dübendorf (DUE) sites: observations and simulations based on Henne et al. (2012) (already scaled with factor 0.068). The x-axis is scaled logarithmically to achieve better comparability. Observations for the year 2018, simulations based on meteorology for 2010. ..... 190 Figure 35: Monthly mean and standard deviation of u-HFC-1234yf concentrations (in ppt) at the Jungfraujoch (JFJ), Mace Head (MHD), Taunus (TNS) and Dübendorf (DUE) sites: observations and simulations based on Henne et al. (2012) (already scaled with factor 0.068). Observations for the year 2018, simulations based on meteorology for 2010. ...................................................................... 191 Figure 36: Frequency distribution of the daily mean values of the observed TFA rainwater concentration (TFA aq. in µg/L) for the DWD measuring stations and the simulated. The simulated TFA-rainwater concentration contains only on TFA from the decomposition of u-HFC-1234yf. Dashed lines indicate the respective median values. The x-axis is scaled logarithmically. .................................................. 194 Figure 37: Frequency distribution of the daily mean values of the observed wet TFA deposition (input in kg/km² per year) for the DWD monitoring stations and the simulated. The simulated TFA input contains only TFA from the atmospheric degradation of u-HFC-1234yf. Dashed lines indicate the respective median values. The x-axis is scaled logarithmically. ................................................................................. 195 Figure 38: Spatial distribution of the simulated mean TFA rainwater concentration (TFA aq. in µg/L) from atmospheric u-HFC-1234yf degradation. The colouring of the points corresponds to the measured annual medians at the DWD stations (SW, Schleswig, GW, Greifswald, PD, Potsdam, BR, Brocken, ES, Essen, WK, Wasserkuppe, SU, Stuttgart, MO, Munich-Oberschleißheim). ................................ 196 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 20 Figure 39: Spatial distribution of the simulated annual sum of wet TFA deposition (input in kg/km² per year) from atmospheric u-HFC-1234yf degradation. The colouring of the points corresponds to the measured annual medians at the DWD stations (SW, Schleswig, GW, Greifswald, PD, Potsdam, BR, Brocken, ES, Essen, WK, Wasserkuppe, SU, Stuttgart, MO, Munich-Oberschleißheim). ................................ 197 Figure 40: Regression analysis between the observed and simulated medians of the yearly residual values (left) of the TFA rainwater concentration (TFA aq. in µg/L) and (right) of the wet TFA deposition (input in kg/km² per year) at the DWD stations. The station BR (open circle) was not used for the regression analysis. a, Axis intercept. b, Slope of the linear regression. N, Number of points. Y-X, Mean difference. BRMS, Bias corrected mean square deviation. r, Correlation coefficient with 95 % confidence interval. ....................................... 198 Figure 41: Estimated contributions to the observed wet TFA deposition at the DWD measuring stations from atmospheric degradation of HFCs (sum of wet and dry deposition), degradation of u-HFC-1234yf (wet and dry deposition) and unexplained fraction (unknown). At the station Brocken the contributions to the observed wet and dry TFA deposition are shown. ...................................................................... 199 Figure 42: Estimated future TFA deposition (input in kilotons per year) (top) and TFA deposition rates (input in kg/km² per year) (bottom) from the atmospheric depletion of u-HFC-1234yf for Europe (EU-28 + Norway, Switzerland and Turkey) with surrounding seas (Europe land area + seas), the land area of Europe (Europe land area) and of Germany (Germany land area). ........................................................................ 201 Figure 43: Concentration of u-HFC-1234yf (left) and u-HFC-1234ze (right) at four different locations in Europe (Mace Head in Ireland, Jungfraujoch and Dübendorf in Switzerland and Taunus Observatory in Germany) from January 2018 (01/18) to May 2019 (05/19). Shown are measuring points and LOESS (locally estimated scatterplot smoothing) regression curves of the measured concentrations. ........................ 203 Figure 44: Classification of air mass sectors for trajectory classification at the Taunus Observatory station at Kleiner Feldberg of the University of Frankfurt. The trajectory classes (sectors) are separated by black lines. The red lines show the backward trajectories of u-HFC-1234yf, u-HFC-1234ze and u-HCFC-1233zd for the last five days since the measurement at Kleiner Feldberg. ................................................... 204 Figure 45: Concentration distribution of u-HFC and u-HCFC measured at the Taunus observatory from air masses of different origin in the period from May 2018 to May 2019. E, east. SW, southwest. W, west. NW, northwest. The y-axis is binary logarithmically scaled. .................... 205 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 21 List of tables Table 1: Overview of groups of halogenated greenhouse gases used in the past and present and key figures on their effect in the atmosphere. ODP, ozone depleting potential. GWP, global warming potential. .... 68 Table 2: Listing of (potentially) relevant and currently in the EU commercially available unsaturated halogenated refrigerants and blowing agents with small GWP. .................................................................................. 76 Table 3: Overview of the HFCs produced in the EU in 2018 with the respective main use and the annual production capacity in metric tons, as well as the production sites in the EU according to expert information. .. 78 Table 4: By-products and intermediates potentially formed during the production of HFCs, as well as starting materials and minor components. ....................................................................................... 79 Table 5: By-products and intermediates potentially formed during the production of u-HFCs and u-HCFCs as well as potential minor components. Toxic substances are marked with †. If not specified, all isomers are potentially included. This list is not exhaustive. ............. 81 Table 6: Usage quantities of reportable HFCs, u-HFCs and u-HCFCs in Germanya in 2016 (Statistisches Bundesamt 2018) and 2018 (Statistisches Bundesamt 2019) and the EU for 2016 (EEA 2017) and 2018 (EEA 2019). Under the heading "Other" all substances are subsumed which had a share of less than 1 % of the total amount used (only HFC, u-HFC and u-HCFC) or which were not used in public. ............................................................................................................ 85 Table 7: Quantities of use of reportable fluorinated greenhouse gases (including mixtures) in the various applications and their share of the total quantity used in Germany 2016 (Statistisches Bundesamt 2018) and 2018 (Statistisches Bundesamt 2019) and the EU-28 2016 (EEA 2017) and 2018 (EEA 2019).a .............................................................. 86 Table 8: List of HFCs and u-HFCs currently used in relevant quantities as single substances and in older and newer mixtures (status: March 2020). . 88 Table 9: Stock of u-HFC-1234yf and u-HFC-1234ze(E) as single substance and in mixtures in various applications since 2012 in Germany in tonnes (only u-HFC, without HFC in mixtures). Survey by Öko-Recherche for the German Federal Environment Agency. Deviations from reported data possible. Sources: unpublished data from inventory survey & Warncke et al. (2017, 2020). .............................................................. 90 Table 10: Shares of emissions from the three phases of the "life cycle" of total emissions by application from the reporting for the German Federal Environment Agency in percent for the year 2015. Source: Warncke et al. (2016). ........................................................................................ 91 Table 11: Total emissions of HFC-1234yf and u-HFC-1234ze(E) in stationary and mobile applications in Germany in tonnes for the years 2012 to 2018 -, no data available. Source: Warncke et al. (2017, 2020). ................. 92 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 22 Table 12: Emissions of u-HFCs from the production of u-HFC-filled appliances in Germany in tonnes from 2013 to 2018. For the year 2012, there were no manufacturing emissions for u-HFC-1234yf, since passenger cars with u-HFC-1234yf were imported into Germany before 2013 but no domestic production took place yet. -, No data available. Source: Warncke et al. (2017, 2020). .............................................................. 93 Table 13: Application examples for niche applications of u-HFCs and u-HCFCs as propellants or technical gases. ........................................................... 94 Table 14: Overview of selected halogenated substances that can form trifluoroacetic acid (TFA) during atmospheric degradation. The complete table is given in Annex A.7. ............................................... 111 Table 15: Environmentally relevant data of further groups of halogenated substances which are not used as refrigerants or blowing agents but may form TFA during atmospheric decomposition. PFAs, partially fluorinated alcohols. HFEs, hydrofluoroether. HCFEs, hydrochlorofluoroether. ................................................................... 112 Table 16: Some characteristics of trifluoroacetic acid (TFA) and trifluoroacetate (here for example the sodium salt of trifluoroacetic acid, sodium trifluoroacetate). .............................................................................. 116 Table 17: Concentrations of trifluoroacetate based on measurements in the hydrosphere for various sites in Germany and modelled trifluoroacetic acid (TFA) concentrations worldwide. ...................... 117 Table 18: Toxicity of various halogenated refrigerants and blowing agents with small GWP according to REACH registration dossiers. LC50, medium lethal concentration (death of 50 % of the untested population). EC50, medium effective concentration (effect in 50 % of the untested population). LOEC, "lowest observed effect concentration" (lowest concentration at which an effect on the organism occurs). NOEC, "no observed effect concentration" (highest dose at which no effect on the organism occurs). -, no data available. (Status: March 2020) ... 124 Table 19: Ecotoxicological information for u-HFC-1234yf, u-HFC-1234ze(E) and u-HCFC-1233zd(E) from the REACH dossiers. Shown is the concentration at which no negative environmental effects are to be expected (PNEC - Predicted No-Effect Concentration). -, no data available. (Status: March 2020) ........................................................ 124 Table 20: Ecotoxicological effects of trifluoroacetic acid (TFA) on various algae and land plants (REACH registration dossier for TFAa). EC10, mean effective concentration (effect in 10 % of the investigated population). EC50, mean effective concentration (effect in 50 % of the investigated population). LC50, mean lethal concentration (death of 50 % of the investigated population). LOEC, "lowest observed effect concentration" (lowest concentration at which an effect on the organism occurs). NOEC, "no observed effect concentration" (highest dose at which no effect on the organism occurs). -, no data available. (Status: March 2020) ........................................................................ 128 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 23 Table 21: Ecotoxicological information for trifluoroacetic acid (TFA) from the REACH dossiers. If available, the Predicted No-Effect Concentration (PNEC) is given. (Status: March 2020) .............................................. 130 Table 22: List of substances and mixtures in the AnaFgas model for the calculations in this project. The substances and mixtures newly added to the 2011 model are written in italics. The double marked mixtures R448A/R449A, R450A/R513A, R454C/R455A are not existing refrigerants but have been combined for the projections. .............. 135 Table 23: Demand and emissions of HCFCs, HFCs, u-HFCs and u-HCFCs in Europe (EU-28) in metric tons from 2000 to 2050 in 10-year steps across all sectors for the “u-HFC and u-HCFC maximum scenario”. 145 Table 24: Overview of the demand and emission quantities of the individual HCFCs, HFCs, u-HFCs and u-HCFCs in Europe (EU-28) in metric tons in the years 2018, 2020, 2030 and 2050 for the “u-HFC and u-HCFC maximum scenario”. D, Demand. E, emissions. ............................... 147 Table 25: Emission quantities of refrigerants and propellants from the groups of HFCs, u-HFCs and u-HCFCs, which form trifluoroacetic acid (TFA) during atmospheric decomposition, for Europe (EU-28) in metric tons in the years from 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. .......................................................................................... 152 Table 26: Summary of the quantities of trifluoroacetic acid (TFA) calculated from European (EU-28) emissions of all TFA-forming HFC, u-HFC and u-HCFC containing refrigerants and blowing agents in metric tons in the years from 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. .......................................................................................... 153 Table 27: Summary of the amount of trifluoroacetic acid (TFA) of all TFA- forming refrigerants and blowing agents containing HFCs, u-HFCs and u-HCFCs in metric tons in the years 2000 to 2050, calculated from the German emissions for the “u-HFC and u-HCFC maximum scenario”. The share of the German (DE) and European (EU-28) total refers to the respective substance. ................................................................. 156 Table 28: Summary of the quantity of hydrogen fluoride (HF) calculated from European (EU-28) emissions of all projected HCFC, HFC, u-HFC and u- HCFC containing refrigerants and blowing agents in metric tonnes in the years 2000 to 2050 for the “u-HFC and u-HCFC maximum scenario”. .......................................................................................... 160 Table 29: Geographical coordinates and altitudes (in m above sea level) of the precipitation sampling sites in different federal states of Germany. .......................................................................................................... 166 Table 30: Precipitation amounts at the studied sites during the periods 2018/19 (February 2018 to January 2019) and 2019/20 (February 2019 to January 2020); for the Stuttgart site: March 2018 to February 2019 (2018/19) and March 2018 to February 2020 (2019/20). ................ 168 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 24 Table 31: Statistical parameters of the trifluoroacetate concentration of (volume-equivalent) monthly composite precipitation samples (MCS) over seven of the eight stations (only wet deposition) per month. The best-case scenario is shown. Data for the Brocken station are not shown as they contain the sum of wet and dry deposition. SD, standard deviation. ........................................................................... 173 Table 32: Statistical parameters of the trifluoroacetate concentration of (volume-equivalent) monthly composite precipitation samples (MCS) of studied sites. Observation period: February 2018 to January 2020 (site Stuttgart: March 2018 to February 2020). The results of the best-case scenario are shown. Note that at site Brocken, the total amount of atmospherically deposited trifluoroacetate instead of only the wet deposited trifluoroacetate was determined. SD, standard deviation. .......................................................................................... 175 Table 33: Statistical parameters of the trifluoroacetate wet-deposition flus of (volume-equivalent) monthly composite precipitation samples (MCS) from February 2018 (02/18) to February 2020 (02/20). Data of the site Brocken, where the total amount of atmospherically deposited trifluoroacetate instead of the wet deposited trifluoroacetate was determined, is not included. The best-case scenario is shown. SD, standard deviation. ........................................................................... 177 Table 34: Statistical parameters of the trifluoroacetate wet-deposition flux of (volume-equivalent) monthly composite precipitation samples (MCS) of studied sites. Observation period: February 2018 to January 2020 (site Stuttgart: March 2018 to February 2020). The results of the best-case scenario are shown. Note that at site Brocken, the total amount of atmospherically deposited trifluoroacetate instead of only the wet deposited trifluoroacetate was determined. SD, standard deviation. .......................................................................................... 179 Table 35: Number of samples, total precipitation and statistical parameters of the trifluoroacetate concentration of individual precipitation samples. Detection limit (DL): 0.025 µg/L. The best-case scenario is shown. Observation period: February 2018 to January 2019 (for site Stuttgart: Mach 2018 to February 2019). ROS, regression on order statistics. Concentrations of trifluoroacetate are reported with three significant figures. ............................................................................. 182 Table 36: Statistical parameters of the trifluoroacetate wet-deposition flux of individual precipitation samples of studied sites. Observation period: February 2018 to January 2020 (site Stuttgart: March 2018 to February 2020). The results of the best-case scenario are shown. Note that at site Brocken, the total amount of atmospherically deposited trifluoroacetate instead of only the wet deposited trifluoroacetate was determined. Fluxes of trifluoroacetate are reported with three significant figures. ............................................ 184 Table 37: Trifluoroacetate concentration in soils at studied sites. TOC, total organic carbon of the respective soil sample. DW, dry weight. FW, fresh weight. ..................................................................................... 186 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 25 Table 38: Trifluoroacetate concentration in soils at different locations and times. DW, dry weight. FW, fresh weight. -, no information available. .......................................................................................................... 186 Table 39: Concentrations of trifluoroacetate in plants (sampling site: Munich- Oberschleißheim). DW, dry weight. FW, fresh weight. n, number of replicates. ......................................................................................... 187 Table 40: Statistics of the observed (O) and simulated (S) TFA rainwater concentrations (in µg/L).MV, mean value. SD, standard deviation. MAD, mean absolute deviation from the median ("Median Absolute Deviation“). ....................................................................................... 194 Table 41: Statistics of observed (O) and simulated (S) wet and dry TFA deposition rates (in kg/km2 per year). MV, mean value. SD, standard deviation. The figures in brackets for the unknown fraction give the uncertainty due to the simulated u-HFC-1234yf deposition. u-HFC is u-HFC-1234yf, HFC is HCFC/HFC. ...................................................... 200 Table 42: Percentage probability of observing u-HFCs and u-HCFCs at the Taunus Observatory as a function of the air mass sector. ............... 205 Table 43: Mean trifluoroacetic acid (TFA) or trifluoroacetate concentration in µg/L and mean TFA or trifluoroacetate input in g/km² and metric tonnes (t) in different regions over various periods of time. mm, mean precipitation sum in mm. MV, measured value. PW, precipitation weighted. SS, single samples for all measuring stations except Brocken. MS, mixed samples for all measuring stations except Brocken. -, data not available. .......................................................... 208 Table 44: Projected amount of trifluoroacetic acid (TFA) from the atmospheric degradation of halogenated substances emitted in Europe (EU-28) in tonnes for different years from 2018 to 2050 (based on emission data from the modelling in Chapter 3). The TFA totals and the percentage share of the different refrigerants and blowing agents in the total amount are shown. In addition, the percentage increase of the TFA total quantity as well as the individual substances or substance groups in relation to 2018 is shown. "Other" includes all substances projected in Chapter 3 except HFC-134a and u-HFC-1234yf. ........... 211 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 26 List of figures Annex Figure A 1: Production quantities of cars in 17 important EU Member States for the years 1999 to 2017. .................................................................... 246 Figure A 2: Box plots of the precipitation-weighted trifluoroacetate concentrations of the volume-equivalent monthly mixed samples of the precipitation from February 2018 (02/18) to January 2020 from seven of the eight measuring stations. Data for the Brocken station are not shown because, in contrast to the results of the other stations, they contain the sums of wet and dry deposition. The worst- case scenario is shown. Grouping of data based on time (month and year). The Stuttgart station is not included in 02/18. The y-axis is scaled binary logarithmically. The periods from February to January are highlighted in different colors. ................................................... 248 Figure A 3: Box plots of the trifluoroacetate concentrations of the volume- equivalent monthly mixed samples of the precipitation from February 2018 to January 2020 (for the Stuttgart station from March 2018 to January 2020). The worst-case scenario is shown. Grouping of the data based on the location (measuring station). Order of the measuring stations according to the descending median concentration. The y-axis is scaled binary logarithmically. At the Brocken (BR) station, wet and dry deposition were recorded together, at all other stations only wet deposition. ......................... 249 Figure A 4: Box plots of the trifluoroacetate deposition via precipitation from February 2018 (02/18) to January 2020 (analysis of the volume- equivalent monthly mixed samples) of all 7 measuring stations, exclusively measuring the wet deposition. The worst-case scenario is shown. Grouping of data based on time (month and year). Station Stuttgart not included in 02/18. Data for the Brocken station are not shown, as they include the sum of wet and dry deposition. The y-axis is scaled binary logarithmically. The periods from February to January are highlighted in color. .................................................................... 250 Figure A 5: Box plots of the trifluoroacetate deposition via precipitation (analysis of the volume-equivalent monthly mixed samples) from February 2018 to January 2020 (for Stuttgart station: from March 2018 to January 2020). The worst-case scenario is shown. Grouping of the data based on the location (measuring station); Order of the measuring stations according to descending median entry. The y-axis is scaled binary logarithmically. Wet and dry deposition were recorded together at the Brocken (BR) station, only wet deposition at all other stations. .............................................................................. 251 Figure A 6: Monthly mean values of the trifluoroacetate concentration in rainwater over all measuring stations in the course of the year, measured using two analyzes, volume-equivalent monthly mixed values in the period February 2018 (02/18) to January 2019 (01/19) and based on the individual samples (best-case Scenario) for the same period. The y-axis is scaled binary logarithmically. ................. 252 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 27 Figure A 7: Monthly mean values of the trifluoroacetate concentration in rainwater over all measuring stations in the course of the year, measured using two analyzes, volume-equivalent monthly mixed values in the period February 2018 (02/18) to January 2019 (01/19) and based on the individual samples (best-case Scenario) for the same period. The x- and y-axes are scaled binary logarithmically. Points on the line are identical. ........................................................ 253 Figure A 8: Monthly mean values of the trifluoroacetate deposition from the rainwater over all measuring stations in the course of the year, measured on the basis of two analyzes, volume-equivalent monthly mixed samples in the period February 2018 (02/18) to January 2019 (19/01) and on the basis of the individual samples (best-case Scenario) for the same period. The y-axis is scaled binary logarithmically. ................................................................................. 254 Figure A 9: Monthly mean values of the trifluoroacetate deposition from the rainwater over all measuring stations in the course of the year, measured on the basis of two analyzes, volume-equivalent monthly mixed samples in the period February 2018 (02/18) to January 2019 (19/01) and on the basis of the individual samples (best-case Scenario) for the same period. The x and y axes are scaled binary logarithmically. Points on the line are identical. .............................. 255 Figure A 10: Boxplots of trifluoroacetate flux of individual precipitation samples grouped by the sampling site. The worst-case scenario is shown. Note that the boxplot of site Stuttgart includes data from March 2018 to February 2019, whereas boxplots from other sites include data from February 2018 to January 2019. Sites are plotted in descending median order. The y-axis is on a logarithmic scale. .......................... 257 Figure A 11: Concentrations of HFC-134a in the atmosphere in ppt in the period from October 1994 (10/94) to March 2018 (03/18). Stations in the northern hemisphere are shown with solid lines, stations in the southern hemisphere with dotted lines. .......................................... 258 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 28 List of tables Annex Table A 1: Search terms for the research on niche applications ....................... 225 Table A 2: List of events attended as part of the project .................................. 228 Table A 3: Niche applications of u-HFCs and u-HCFCs based on an online search. .......................................................................................................... 229 Table A 4: Overview of all halogenated substances currently known to us that can form TFA during atmospheric degradation. This also includes commercially insignificant substances. The TFA formation potential is largely determined by the halogenated end products, whereby CF3CFO (TFF) and CF3CClO (TFAC) are practically 100 % converted to TFA, CF3CHO (trifluoroacetaldehyde) up to 10 %. ............................ 232 Table A 5: Stock shares of different refrigerants and their alternatives in different sectors in Germany from 2010 to 2016 in percent. Source: Warncke et al. (2017). -, No data available. ..................................... 241 Table A 6: Assumptions on the market penetration of refrigerants and propellants in the various areas of application up to 2050 in the EU- 28 in percent in the AnaFgas model. For standardized mixtures (e.g. R450A / R513A) the mean GWP for both mixtures is given. ............ 242 Table A 7: Material that was made available to each DWD station involved in the measurement program. ............................................................. 247 Table A 8: Overview of sample size, annual precipitation, as well as a summary of the trifluoroacetate concentrations of the individual measurements at the locations examined. Detection limit (DL): 0.025 µg/L. The worst-case scenario is shown. Investigation period: February 2018 to January 2019 (for the Stuttgart station: March 2018 to February 2019). Concentrations with three significant digits each. .......................................................................................................... 256 Table A 9: Summary of the trifluoroacetate flux (individual sample analysis) at the investigated locations. The worst-case scenario is shown. Study period: February 2018 to January 2019 (for the Stuttgart station: March 2018 to February 2019). Entries with three significant digits each. ................................................................................................. 256 UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 29 List of abbreviations AGAGE Advanced Global Atmospheric Gases Experiment AHRI Air Conditioning, Heating and Refrigeration Institute AnaFgas Analysis of Fluorinated Greenhouse Gases (emissions model for the EU) ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers BR Abbreviation for the rainwater measuring station Brocken (Germany) CAS Chemical Abstracts Service CFC chlorofluorocarbon (fully halogenated) CoRAP Community Rolling Action Plan CRI-STOCHEM name of the chemical transport model DFG German Research Foundation DKV German Society for Refrigeration and Air Conditioning e.V. DL detection limit DNEL derived no-effect level DUE abbreviation for the atmospheric measuring station Dübendorf (Switzerland) DW dry weight ECHA European Chemicals Agency ECx concentration that leads to a change in the reaction of x % in a given time (e.g. EC10 or EC50) EC50 average effective concentration (effect in 50 % of the studied population) ECETOC European Centre for Ecotoxicology and Toxicology of Chemicals EEA European Environment Agency Empa Swiss Federal Laboratories of Materials Science and Technology EPA United States Environmental Protection Agency ES abbreviation for the rainwater measuring station Essen (Germany) EU European Union EU-28 European Union with 28 Member States (including United Kingdom) EU-28+ European Union with 28 Member States (including United Kingdom) plus Norway, Swit- zerland and Turkey FELS-test Fish, Early-Life Stage Toxicity Test FLEXPART FLEXible PARTicle dispersion model FW fresh weight PFC perfluorocarbon (fully halogenated) F-gas fluorinated (greenhouse) gas HCFC hydrochlorofluorocarbon (partially halogenated) UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 30 GC-MS gas chromatography-mass spectrometry GHG greenhouse gas GOW health orientation value (German: Gesundheitlicher Orientierungswert) GW abbreviation for the rainwater measuring station Greifswald GWP global warming potential HCFE hydrochlorofluoroether HCC partially chlorinated hydrocarbon HF hydrogen fluoride HFE hydrofluoroether HFC hydrofluorocarbon (partially fluorinated) HFO hydrofluoroolefin (older Anglo-Saxon name for unsaturated HFCs; see u-HFC) IPCC Intergovernmental Panel on Climate Change ISO International Organisation for Standardization JFJ abbreviation for the atmospheric measuring station Jungfraujoch (Switzerland) LC50 average lethal concentration LOEC lowest observed effect concentration LOESS locally estimated scatterplot smoothing MAC mobile air conditioning MAK maximum work place concentration (German: Maximale Arbeitsplatzkonzentration) MHD abbreviation for the atmospheric measuring station Mace Head (Ireland) MDI metered-dose inhaler MIN-scenario scenario of minimal HFC-use, i.e. of minimal HFC-emissions MO abbreviation for the rainwater measuring station Munich-Oberschleißheim (Germany) MP Montreal Protocol on Substances that Deplete the Ozone Layer NHN standard elevation zero (German:Normalhöhennull) NIR National Inventory Report: detailed description and numerical information for reporting to UNFCCC NLKWN Lower Saxony State Agency for Water Management, Coastal Protection and Nature Con- servation (Germany) NOEC no observed effect concentration OECD Organisation for Economic Co-operation and Development ODP ozone depletion potential ODS ozone depleting substance OH-radical hydroxyl radical OICA Organisation Internationale des Constructeurs d'Automobiles (international organiza- tion of automobile producers) UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 31 PD abbreviation for the rainwater measuring station Potsdam (Germany) PFA partially fluorinated alcohol PFMP perfluoro(2-methyl-3-pentanone) PFOA perfluorooctanoic acid PFOS perfluorooctanesulfonic acid PNEC predicted no effect concentration PU polyurethane QSAR quantitative structure-activity relationship model REACH Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals ROS regression on order statistics SCAS-Test semi-continuous activated sludge test SD standard deviation SU abbreviation for the rainwater measuring station Stuttgart (Germany) SW abbreviation for the rainwater measuring station Schleswig (Germany) TCA trichloroacetic acid TEAP Technology and Economic Assessment Panel TFA trifluoroacetic acid TFAC trifluoroacetyl chloride TFF trifluoroacetyl fluorid TNS abbreviation for the atmospheric measuring station Taunus (Germany) TOC total organic carbon TZW DVGW-Technologiezentrum Wasser (German Water Centre) (Karlsruhe, Germany) u-HCFC unsaturated HCFC u-HFC unsaturated HFC UBA German Environment Agency UNEP United Nations Environment Programme UNFCCC United Nations Framework Convention on Climate Change UStatG German Environmental Statistics Act VRF variable refrigerant flow WAM-scenario with-additional-measures-scenario WD wet deposition WK abbreviation for the rainwater measuring station Wasserkuppe (Germany) WMO World Meteorological Organization XPS extruded polystyrene UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 32 Summary Halogenated hydrocarbons are often used as refrigerants and blowing agents in foams. Further areas of application include the use as propellant for aerosols and metered dose inhalers as well as solvents and fire extinguishing agents. This report provides an overview of the status of the use of halogenated refrigerants and blowing agents and possible future developments. The study particularly includes substance aspects of the life cycle and focuses on the introduction of persistent degradation products of halogenated refrigerants and blowing agents into the environment in Germany and Europe (EU- 28)1. Particular consideration is given to new halogenated substances with low global warming poten- tial (GWP). Motivation Fully halogenated chlorofluorocarbons (CFCs), which are largely responsible for the depletion of the ozone layer and have a high global warming potential, were as a result of the Montreal Protocol re- placed by hydrochlorofluorocarbons (HCFCs) with a smaller ozone-depleting potential. Due to a fur- ther tightening of the Montreal Protocol, HCFCs had to be replaced by hydrofluorocarbons (HFCs) since the 1990s as well. On the grounds of their high global warming potential, HFCs are gradually being withdrawn from the market now. Since 2006, HFCs have been subject to restrictive regulations in the European Union (EU)2. The revised F-Gas Regulation3 stipulates a progressive shortage of HFC-quantities since 2015, based on the global warming potential of the regulated substances. In 2016, HFCs were included in the Montreal Protocol with the Kigali Agreement. In the future, therefore, only small quantities of HFCs will be available in Europe and worldwide and will tend to be reserved for use in essential niche appli- cations. As of today, halogen-free refrigerants such as hydrocarbons, carbon dioxide (CO2) and ammonia (NH3) are established alternatives to halogenated substances in many applications. These substances were used as refrigerants prior to halocarbons and are now often referred to as “natural refrigerants”. The best example is the almost exclusive use of isobutane (R600a) as a refrigerant in household refrigera- tors (fridges) in Europe, which has been used since the mid-1990s and is now accepted worldwide. Large industrial refrigeration systems often use natural refrigerants such as ammonia. In commercial refrigeration, the proportion of systems with CO2 and hydrocarbons is steadily increasing. Halogenated substances from the group of unsaturated HFCs (u-HFCs, often referred to as HFOs4) with short atmospheric lifetimes and low global warming potentials are increasingly offered on the market. In addition, chlorinated substances are being developed in the form of unsaturated HCFCs (u-HCFCs, often referred to as HCFOs5) that (again) have an ozone-depleting potential. Unsaturated HFCs and HCFCs have low global warming potentials, albeit the impact of the large-scale use of these substances and in particular their persistent degradation products on the environment has not been extensively investigated. This report is intended to contribute to this question. 1 Unless otherwise stated, “Europe” is used synonymously with “EU-28” in this report. The EU-28 includes all 28 Member States of the European Union as it existed until February 1, 2020 (including the United Kingdom of Great Britain and Northern Ireland). 2 F-gas Regulation (EC) No 842/2006 and Directive 2006/40/EC (MAC-Directive) 3 F-gas Regulation (EU) No 517/2014 4 Short for hydrofluoroolefin, a term used by industry in the Anglo-Saxon region 5 Short for hydrochlorofluoroolefin, a term used by industry in the Anglo-Saxon region UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 33 Assessment of the current status In a first step, the current status was analysed (Chapter 2). The entire life cycle of of the investigated halogenated refrigerants, foam-blowing agents and aerosol propellants including the atmospheric deg- radation was mapped. Applications, quantities, and compositions of halogenated greenhouse gases in Germany and Europe as well as their emissions during production, use and disposal are presented. Furthermore, information on by-products from the manufacture and secondary components of the in- vestigated substances was compiled. The degradation routes and degradation products of halogenated greenhouse gases were identified in detail and their pathways into the environment quantified. Fi- nally, the impact of these degradation products on the environment was evaluated. Relevant substitutes with low GWP, which are already currently used in large quantities as refriger- ants, foam blowing agents and aerosol propellants are listed in Table S 1. These are u-HFC-1234yf, as a replacement for HFC-134a in mobile air conditioning systems for cars since 2011, u-HFC-1234ze(E), as a replacement for HFCs with high GWP as a foam blowing agent and propellant for aerosols, as well as u-HFC-1336mzz(Z) and u-HCFC-1233zd(E) as replacements for HFCs as foam blowing agents. The u-HFC-1234yf and the u-HFC-1234ze(E) are also components of many new refrigerant mixtures (so called blends) that are used in refrigeration and air conditioning. Table S 1: List of unsaturated halogenated refrigerants, foam blowing agents and aerosol propel- lants with low global warming potential currently commercially available in Europe (EU- 28). Substance name Chemical name Molecular formula Main use u-HFC-1234yf 2,3,3,3-tetrafluoropropene CF3CF=CH2 refrigerant u-HFC-1234ze(E) (1E)-1,3,3,3-tetrafluoropropene trans-CF3CH=CHF refrigerant, foam blowing agent, aerosol propellant u-HCFC-1233zd(E) (E)-1-chloro-3,3,3-trifluoropro- pene trans-CF3CH=CHCl refrigerant, foam blowing agent u-HFC-1336mzz(Z) (2Z)-1,1,1,4,4,4-hexafluorobu- tene cis-CF3CH=CHCF3 foam blowing agent u-HFC-1336mzz(E) (2E)-1,1,1,4,4,4-hexafluorobu- tene trans-CF3CH=CHCF3 refrigerant u-HCFC-1224yd(Z) cis-1-chloro-2,3,3,3-tetraflu- oropropene cis-CF3CF=CHCl refrigerant, foam blowing agent Emissions from the manufacture, use and disposal of HFCs, u-HFCs and u-HCFCs The production of halogenated greenhouse gases in Europe is limited to a few HCFCs and HFCs. HFC- 134a, HFC-365mfc, HFC-227ea, HFC-143a, and HCFC-22 are produced in relevant quantities. Halogen- ated substitutes with low GWP are mainly produced in the US and in China as well as in Japan and in India. Quantitatively, the most relevant by-product in Europe is HFC-23, which is formed especially during the production of HCFC-22. The emissions from production have rarely been investigated and are usually neither identified nor quantified. The tables in Chapters 2.4.1 and 2.4.2 (Table 4 and Table 5) list some of the by-products and intermediates, as well as chemical precursors and potential sec- ondary components, based predominantly on analysis of literature and patents. A solid data basis on the use of halogenated greenhouse gases in Europe and Germany are freely avail- able annual reports from the European Environment Agency (EEA) based on the reporting obligations UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 34 set out by the EU F-Gas Regulation6 as well as annual surveys of the German Federal Statistical Office7. The data show that HFC-134a contributes by far the largest share of the halogenated greenhouse gases used in the EU and especially in Germany. In 2018, this share was 38 % for the EU and 46 % for Ger- many. The share of u-HFC-1234yf was 13 % in the EU and 24 % in Germany (Table 6 in Chapter 2.5.1). From 2016 to 2018, the share of u-HFC-1234yf in the EU increased almost three times, in Germany even four times, mainly due to the substitution of HFC-134a with u-HFC-1234yf in mobile air condi- tioning (for passenger cars). The largest area of application for fluorinated greenhouse gases in 2018 was the refrigeration sector with 74 % in the EU and 77 % in Germany. Foam blowing agents were used with a share of 12 % in the EU and 15 % in Germany, propellants for aerosols had a share of 10 % and 7 %, respectively (Table 7 in Chapter 2.5.1). In all sectors, the use phase is responsible for the larg- est contribution to total emissions (Table 10 in Chapter 2.5.2). The disposal or intended destruction of halogenated greenhouse gases was also quantified based on the EU F-gas reporting. HFCs account for 85 % of the destroyed amount of halogenated greenhouse gases, about half of which is HFC-23. As a result of operational and vehicle accidents, halogenated greenhouse gases can be inadvertently destroyed. The products of an uncontrolled combustion de- pend on many factors, in particular the temperature and the available reaction partners. Complete thermal decomposition primarily produces hydrogen fluoride (HF), which forms in contact with mois- ture highly toxic hydrofluoric acid. The new halogenated substitutes with low GWP generally have a higher flammability than their predecessors with high GWP, which also increases the probability of the formation of toxic hydrofluoric acid in the event of accidental release. Atmospheric Degradation Once these gases have been released into the atmosphere, atmospheric degradation starts with an ini- tial reaction, primarily with OH radicals. Halogenated carbonyl compounds are formed as intermediate products. The type of intermediate product determines the further degradation pathway in the atmos- phere. For HFCs, u-HFCs and u-HCFCs, most of the halogenated carbonyl compounds formed are fur- ther broken down to hydrogen fluoride (HF) and carbon dioxide (CO2), except for the two compounds trifluoroacetyl fluoride (TFF, CF3CFO) and trifluoroacetaldehyde (CF3CHO). With water, TFF reacts completely to the highly persistent and highly mobile trifluoroacetic acid (TFA, CF3COOH). For tri- fluoroacetaldehyde, a TFA formation rate of up to 10 % can be assumed. Now and in the future, large quantities of two substances that strongly form TFA will be used, namely HFC-134a, of which 7-20 % is degraded to TFA on a molar basis and u-HFC-1234yf, which completely degrades to TFA (Figure S 1). Additionally, there are further halogenated gases that form TFA during atmospheric degradation (see Table 14 in Chapter 2.7.4 and Table 15 in Chapter 2.8). 6 Article 19 of Regulation (EU) Nr. 517/2014 7 Report on the collection of certain climate-relevant substances by the German Federal Statistical Office. UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 35 Figure S 1: Atmospheric degradation of HFC-134a (left) and u-HFC-1234yf (right) via the fluorinated intermediates trifluoroacetyl fluoride (TFF, CF3CFO), CF3 radicals and HCFO to the termi- nal fluorinated degradation products trifluoroacetic acid (TFA) and hydrogen fluoride (HF). Source: own research, Öko-Recherche Demand for and emissions of halogenated refrigerants and blowing agents up to the year 2050 For a comprehensive assessment of the use and emissions of halogenated refrigerants and blowing agents up to the year 2050 and the resulting TFA amount in the 28 EU Member States (EU-28), a model for the projection of halogenated greenhouse gases was used (Chapter 3). This model comprises all relevant sectors in which fluorinated greenhouse gases are used in Europe and projects the demand and emissions for each substance in each sector up to the year 2050. The model includes new halogen- ated substitutes with low GWP and all available data from the reporting to the UN Climate Secretariat, as well as other models, market information and expert surveys. The aim of the projections was to develop a scenario in which a maximum market penetration of halo- genated substitutes in relation to natural substances is assumed in every application in the refrigera- tion, air conditioning, foam blowing and aerosol propellant sector, unless an alternative with halogen- free substitutes is already established or very likely to be established from the current perspective. The annual emissions calculated by the model were then offset against the substance-specific TFA for- mation rates in order to determine the maximum annual TFA quantities to be expected from the at- mospheric degradation of halogenated substances in Europe (EU-28). The projections show only a very small decrease in the total demand for HFCs, u-HFCs and u-HCFCs from about 96,000 tonnes in 2020 to approximately 92,000 tonnes in 2050. The total emissions con- tinue to rise from about 61,000 tonnes in the year 2020 to around 67,000 tonnes in 2050 (Figure S 2, Table 23). In the air-conditioning and refrigeration sector, the demand consists of the initial refriger- ant charge if units are manufactured in the EU-28, part of which emits in the course of the equipment’s lifetime, and the refilling quantities added during servicing. Emissions typically occur with a time lag TFF TFF TFF 100 % TFA CF3CF=CH2 (u-HFC-1234yf) CF3CF(O•)CH2(OH) + NO2 OH• O2, NO• CF3CFO + CH2(OH)(•) CF3COOH CF3CF(OH)CH2O• + NO2 Δ 100 % TFA CF3CFO + CH2(OH)(•) CF3COOH O2 CF3CF(OH)(•) + HCHO Δ7-20 % TFA CF3CFH2 (HFC-134a) CF3CFHO• + NO2 + H2O OH• O2, NO• CF3CFO CF3 • + HCFO ΔO2 + HO2 • CF3COOH HF + HCOOH OH• + HF + HF + HF H2O 100 %H2O H2O CF2O + FNO CO2 + HF H2O O2 NO• HF CH4/ H2O UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 36 to the initial charging and include the release of gases during the use phase and the disposal of end-of life equipment. Figure S 2: Demand and emissions of HCFCs (up to 2015)8, HFCs, u-HFCs and u-HCFCs in Europe (EU- 28) in kilotonnes for the period from 2000 until 2050. Source: own research, Öko-Recherche In 2020, the mobile air conditioning sector accounted for both the highest refrigerant demand of around 31,600 tonnes and the highest emissions of about 29,500 tonnes. At present, existing vehicles using HFC-134a are the main emission source, while from 2030, u-HFC-1234yf will be the refrigerant with the highest demand and emissions. Mobile air conditioning systems in passenger cars have the largest share in every case. Stationary air conditioning, which includes room air conditioners, heat pumps and chillers, does not show an increase in demand of around 25,000 tonnes in the projections from 2020 onwards, while emissions will rise from around 9,000 tonnes in 2020 to around 16,000 tonnes in 2050. For the refrig- eration sector, a demand of around 17,000 tonnes in 2020 is calculated, followed by a demand of around 13,000 tonnes for foam blowing. While the demand in the refrigeration sector will drop to around 13,000 tonnes by 2050, it will remain constant at around 13,000 tonnes for foam blowing agents. In terms of emissions, the sectors differ largely: While emissions from the refrigeration sector will de- crease by almost half from around 9,000 tonnes to around 5,000 tonnes in the period from 2020 to 8 Since 1 January 2010 the refill of refrigeration and air conditioning units with virgin HCFCs is banned in the EU according to EU Regulation No 1005/2009. Since 1 January 2015 also the use of recycled HCFCs for the servicing of refrigeration and air conditioning units is prohibited. UBA Texte Persistent degradation products of halogenated refrigerants and blowing agents in the environment – Final report 37 2050, projected emissions from the foam sector will increase from approximately 5,000 tonnes to around 6,000 tonnes. In the remaining sectors, demand and emissions will grow just slightly in the years from 2020 to 2050: Demand will rise from about 9,000 tonnes to around 10,000 tonnes and emissions are projected to increase from ca. 5,000 tonnes to around 6,000 tonnes. When looking at demand and emissions by substance, it becomes apparent that especially HFC-125, HFC-134a, HFC-32, u-HFC-1234yf and u-HFC-1234ze will play a greater role in the period from 2000 to 2050. The quantities of substances with a higher GWP such as HFC-125 and HFC-134a will decrease sharply by 2050. TFA quantities arising from halogenated substances On the basis of the projected emissions, the amount of TFA arising from each substance in the various application areas was calculated. For 2020, this resulted in a total TFA quantity of slightly less than 15,000 tonnes in the EU-28, which will ri