MANDATE

The Ad hoc Working Group on Further Commitments from Annex I Parties under the Kyoto Protocol (AWG-KP), at its sixth session, requested the secretariat to prepare a compilation of technical information on the following gases included in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC):

· the new hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs), that have been developed since the adoption of the Kyoto Protocol;

· nitrogen trifluoride (NF₃);

· trifluoromethyl sulphur pentafluoride (SF₅CF₃);

· fluorinated ethers (HFEs);

· perfluoropolyethers (PFPEs);

· hydrocarbons (HC) and other compounds including dimethylether (CH₃OCH₃), methyl chloroform (CH₃CCl₃), methylene chloride (CH₂Cl₂), methyl chloride (CH₃Cl), dibromomethane (CH₂Br₂), bromodifluoromethane (CHBrF₂) and trifluoroiodomethane (CF₃I);

as well as on existing stocks and potential emissions of chlorofluorocarbon (CFCs) and hydrochloro-fluorocarbons (HCFCs), and to make it available on the UNFCCC website for consideration by the AWG-KP at its resumed sixth session.

The list of gases included in the AWG-KP report from its sixth session covers substances referred in table 2.14 (addendum¹) of the IPCC AR4 - including the new HFCs and PFCs - that were not listed in the Second Assessment Report (SAR) of the IPCC, and that are not included in the reporting and accounting obligations under the current commitments of the Kyoto Protocol. According to the IPCC (section 2.10.2 of volume 3 of the AR4) table 2.14 covers all gases for which either significant concentrations or large trends in concentrations have been observed, or a clear potential for future emissions have been identified.

¹ The addendum of the IPCC AR4 was released on 5 August 2008 and it is available at http://www.ipcc.ch/publications_and_data/ar4/wg1/en/errataserrata-errata.html

APPROACH

The secretariat invited Parties and experts to provide relevant information on the new gases mentioned above, which they could share with other Parties and the secretariat. The secretariat also contacted experts from the Montreal Protocol secretariat, the Technology and Economic Assessment Panel (TEAP) of the Montreal Protocol, and the Intergovernmental Panel on Climate Change (IPCC). The secretariat also reviewed other relevant information.

SOURCES OF INFORMATION

Information collected by Parties and experts is mostly found on the internet. Important sources of information are:

· The IPCC/TEAP special report on "Safeguarding the Ozone Layer and the Global Climate System: Issues related to hydrofluorocarbons and perfluorocarbons";

· The TEAP’s "Task Force Decision XX/8 Report: Assessment of Alternatives to HCFCs and HFCs and Update of the TEAP 2005 Supplement Report Data", that was published in May 2009 (hereinafter referred to as the 2009 TEAP report); and

· The TEAP’s 2010 progress report "Assessment of HCFCs and environmentally sound alternatives; Scoping study on alternatives to HCFC refrigerants under high ambient temperature conditions", that was published in May 2010 (hereinafter referred to as the 2010 TEAP report).

All values of Global Warming Potential (GWP), radiative efficiency and lifetime for gases included in this compilation are from table 2.14 of the AR4.

Information on methodologies to estimate GHG emissions is found in the Revised 1996 IPCC Guidelines for national greenhouse gas inventories (hereinafter referred to as the Revised 1996 IPCC Guidelines ), and associated Good practice guidance and uncertainty management in national greenhouse gas inventories (hereinafter referred to as the good practice guidance). Another source of information is the 2006 IPCC Guidelines for national greenhouse gas inventories (hereinafter referred to as the 2006 IPCC Guidelines ) that was prepared upon invitation of the UNFCCC. The 2006 IPCC Guidelines comprise the most recent scientific information on methods to assess emissions by source and removals by sinks. Parties to the UNFCCC are using the 2006 IPCC Guidelines on a voluntary basis.

When considering information on methodologies due consideration is to be given to dependency of the occurrence of emissions to the atmosphere on the conditions under which the chemical substance is manufactured, transported, used and disposed. Also relevant are the conditions under which equipments containing the substance are operated, serviced and decommissioned. In some situations, such as high temperatures, compounds may be emitted even if they have low volatility and are inert substances at normal temperatures and pressures.

OVERVIEW OF THE INFORMATION AVAILABLE

The compilation by the secretariat includes information on a gas-by-gas basis, on GWP, application (where the gas is actually or potentially used), production, substitutes and alternative technologies, and the existence of methodologies to estimate greenhouse gas (GHG) emissions. Links to web sites on which more information on these gases can be found are also included.

Also included is a summary on available information on existing stocks (banks) and potential emissions of CFCs and HCFCs.

UPDATES

This compilation reflects the information available to the secretariat as at 27 July 2010, updated after request from some Parties.  This most recent update comprises, in addition to the information previously compiled by the secretariat, further information on HFCs, NF₃ and HFEs.

1. Hydrofluorocarbons (HFCs)

List of substances: The AR4 includes a number of HFC compounds proposed for inclusion in the accounting of GHGs in addition to the HFCs that were already covered by previous IPCC reports² and the IPCC good practice guidance.

Main applications: possible ozone depleting substitutes (ODS) foam blowing agents.

Generally, substances listed as HFCs and PFCs are primarily used to replace ODS controlled under the Montreal Protocol, and their use has became more prevalent in developed countries. Also generally, HFCs include substances that can be used for refrigeration and air conditioning, foam blowing, aerosols and fire extinguishing.

HFC-245fa and HFC-365mfc were originally used in developed countries as a substitute for the HCFC-141b in foam blowing applications, and following the phase-out of this substance. Their use is decreasing however, since other options are available for foam blowing which do not include HFCs or that use co-blowing with HFCs and water. In developing countries, the replacement of HCFC-141b, will be to some degree done by HFC-245fa, but also in these countries activities are underway to develop and apply low-GWP alternatives such as methyl formate and other blowing agents.

The other gases on the list, HFC-152, HFC-161 and the isomers HFC-236cb and HFC-236ea have not seen significant application. These substances are not in commercial use yet and there are no indications for any significant production on a commercial scale in the future.

Given the current trend to replace HCFCs and HFCs with hydrocarbons, mixes of hydrocarbons, HFCs of lower GWP value or recent unsaturated HFCs such as HFC-1234ze, it is very likely that the use of HCFC-161 and HFC-152 will never be globally significant.

Emissions reduction options

Several non-fluorocarbon blowing agents technologies (applying other products such as hydrocarbons, carbon dioxide, water and supercritical carbon dioxide gas) and new lower GWP blowing agent gases have already been developed and are being used.

The TEAP has published an assessment of alternatives to HCFCs and HFCs and updated the data in the 2009 and 2010 TEAP reports. The TEAP reports contain a detailed analysis of the current status of use of fluorinated gases for each sector (refrigeration and air conditioning in domestic, commercial and industrial uses, transportation, foam blowing, fire protection, solvents and inhaled therapy). The TEAP reports show potential opportunities to replace HFCs with substances that have low global warming effect, as follows:

· Use of hydrocarbons in domestic refrigerators and freezers: currently, about 63 per cent of new domestic refrigerators employ HFC-134a, and 36 per cent use hydrocarbons - mainly HC-600a (isobutene) - and it is expected that, within 10 years under business-as-usual, at least 75 per cent of all new production of domestic refrigerators and freezers will use hydrocarbons as refrigerant;

· Use of HC-600a and HC-290 (propane) in stand-alone commercial refrigeration, replacing HFC-134a, which is the current dominant refrigerant. Many companies have already started using hydrocarbons in specific uses such as water fountains and ice-cream freezers;

· Use of R-744 (CO₂) in new direct systems, and use of CO₂ and hydrocarbons as primary refrigerants or heat transfer fluids (HFT) in indirect systems, in large commercial centralized systems;

· Use of R-717 (ammonia) and CO₂ (use of cascade systems by combining the two options for medium and lower temperature) for large refrigerant systems;

· Use of HFC-32, with its lower GWP value, is likely to be an alternative to HCFC-22, while CO₂ and hydrocarbons are expected to see increased usage in specific conditions. Unsaturated HFCs³, such as HFC-1234yf (mostly in blends with other saturated HFCs) might emerge in the next years as replacements of R-410A and R-407C in unitary air conditioners;

· Use of hydrocarbons and CO₂ as most promising replacement candidates for HCFC-22 in transport refrigeration;

· Use of ammonia, hydrocarbons (HC-290 or propylene (HC-1270)), CO₂  and HFC-1234yf as alternatives to chiller refrigerants The use of unsaturated HFCs such as HFC-1234yf, HFC-1234zf or -ze is under development and analysis where it concerns design changes;

· Use of CO₂, HFC-152a or HFC-1234yf, as replacements for HFC-134a and HCFCs for mobile air conditioning. In the European Union (EU), and in accordance with the EU’s mobile air conditioning directive; it is very likely that the choice for mobile air conditioning (MAC) refrigerants equipping new model cars from 2011 on is HFC-1234yf. It is expected that the large market that MACs represents will drive a more widespread market for the unsaturated chemical HFC-1234yf;

· Use of hydrocarbons, methyl formate (trade name Ecomate)Methylal, CO₂, and water is being considered as alternative for replacement of HCFCs and HFCs as blowing agents in the production of foams (polyurethane (PU) and Polystyrene (XPS). In PU foams, hydrocarbons are the main replacements for the use of HCFC-141b and HFCs with higher GWPs (HFC-245fa and HFC-365mfc/HFC-227ea). Unsaturated HFCs, such as HFC-1234ze, are emerging as alternative blowing agents in PU foams with some potential for replacement, but evaluation of their toxicity, environmental impact and foam performance still needs to be completed. The use of HCFCs in XPS foams is being replaced by a combination of HFCs,CO₂, HCs and water, while HCFC-1234ze has been emerging as blowing agent (used in one pilot plant in Turkey);

· Use of hydro-fluoro-ethers (HFE) as possible options for replacement of HCFCs (HCFC-141b and HCFC-225ca/cb) and HFC (HFC-43-10mee and HFC-c447ef) solvents in specialized niche applications, but it is probable that their use will be limited due to the high cost of HFEs;

· Use of dry powder inhalers (DPI) for inhaled drugs partly and gradually replacing the use of HFC-134a and HCF-227ea in propellant MDIs.

Production

The main producers of HFC-245fa are in the United States of America and Japan, while those of HFC-365mfc are in Europe. Global annual production of these gases is estimated around 20,000 tonnes per year each.

Methodologies to estimate emissions

Methodologies to estimate “emissions of fluorinated substitutes for ODS”, available in the 2006 IPCC Guidelines, or “emissions of substitutes for ODS” from the good practice guidance, are usually not specific of individual gases, and may be used to estimate emissions for the extended list of HFCs. Specific emission factors to estimate emissions of some new HFCs (HFC-245fa and HFC-365mfc) from the production and use of foams are available in the 2006 IPCC Guidelines.

References

EU. 2006. Directive 2006/40/EC of the European Parliament and of the Council of 17 May 2006 relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC. Available at http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:161:0012:0018:EN:PDF

UNEP/TEAP. 2009. Assessment of Alternatives to HCFCs and HFCs and Update of the TEAP 2005 Supplement Report Data. Task Force Decision XX/8 Report. UNEP Technology and Economical Assessment Panel. Available at http://ozone.unep.org/Assessment_Panels/TEAP/Reports/TEAP_Reports/teap-may-2009-decisionXX-8-task-force-report.pdf.

UNEP/TEAP. 2010. Assessment of HCFCs and environmentally sound alternatives; Scoping study on alternatives to HCFC refrigerants under high ambient temperature conditions. Task Force Decision XXI/9 Report. UNEP Technology and Economical Assessment Panel. Available at  http://www.unep.ch/ozone/Assessment_Panels/TEAP/Reports/TEAP_Reports/teap-2010-progress-report-volume1-May2010.pdf.

²For the Kyoto Protocol in its first commitment period the GWP used to calculate the CO₂ eq of anthropogenic emissions by sources and removals by sinks of greenhouse gases listed in Annex A shall be those accepted by the IPCC and agreed upon by the Conference of the Parties at its third session. Any revision to a global warming potential shall apply only to commitments under Article 3 in respect of any commitment period adopted subsequent to that revision. (paragraph 3 of Article 5 of Decision 1/CP.3). Paragraph 3 of Decision 2/CP.3 reaffirms that GWP used by Parties should be those provided by the IPCC in its Second Assessment Report (1995 IPCC GWP values).
³There are other new chemical products, referred as unsaturated HFCs or HFOs (hydro-fluoro-olefins), such as HFC-1234yf, HFC-1234ze and HFC-1243zf, which are very short-lived substances and have no established GWP, and are not included in the present information.

.

2. Perfluorocarbons (PFCs)

List of substances: PFC-9-1-18 is also referred to as Perfluorodecalin

Main applications: medical applications

Perfluorodecalin is used in several cosmetic and medical applications as a first-generation PFC-based blood substitutes, exploiting its ability to carry oxygen to living tissues. It is also used in retinal surgery (to repair retinal tears), for treating lung disorders (pneumonectomy), wound healing, as an ultrasonic contrast agent in MRI and ultrasonic examinations, treatment of diseases of the middle ear, and in organ storage for transplants (e.g. pancreatic tissue). In all these uses, this PFC is vented to the atmosphere, although current global production is small (of order 10 tonnes per year). All but pancreatic storage and eye surgery involve only small quantities and are at the research stage.

Recently, perfluorodecalin has been proposed as a carrier of glassified microspheres that contain vaccines, reducing the need for refrigeration. This potential use would increase emissions substantially, to the same order of magnitude of current day emissions of SF₆.

Emissions

Perfluorodecalin is a heavy cyclic molecule, with high boiling point (142 C), and emissions or atmospheric abundance depend on the conditions under which this chemical is managed (e.g. high temperature conditions). The amount of this substance that is being used today combined with the low emissions occurring under most use circumstances indicate that emissions have small significance so far.

Methodologies to estimate emissions

Methodology guidance to estimate emissions of Perfluorodecalin is included in chapter “Use of SF₆ and PFCs in other products” of the 2006 IPCC Guidelines (chapter 8.3, volume 3).

References

IPCC. 2006. 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). Published: IGES, Japan. Available at http://www.ipcc-nggip.iges.or.jp/public/2006gl/index.html.

Shine K.P et al. 2005. Perfluorodecalin: global warming potential and first detection in the atmosphere, Atmospheric Environment 39 (2005) 1759–1763.

3. Nitrogen trifluoride (NF₃)

Other names

Nitrogen fluoride, Trifluoramine and Trifluorammonia

Main applications: manufacture of semiconductors, LCD and photovoltaic cells

Nitrogen trifluoride is used as a replacement for PFCs (mostly C₂F₆) and SF₆ in the electronic industry (plasma etching and chamber cleaning), manufacture of semi-conductors and LCD panels (Liquid Crystal Display). NF₃ is broken down into nitrogen and fluorine gases in situ, and the resulting fluorine radicals are the active cleaning agents that attack the poly-silicon. Nitrogen trifluoride is also used in the photovoltaic industry (thin-film solar cells) for "texturing, phosphorus silicate glass (PSG) removal, edge isolation and reactor cleaning after deposition of silicon nitrate or film silicon". Nitrogen trifluoride is further used in hydrogen fluoride and deuterium fluoride lasers, which are types of chemical lasers.

Emissions

One key reason for increasing interest in nitrogen trifluoride by the semiconductor industry is that it has a higher percentage of conversion to fluorine, which is the active agent in the industrial process, than PFCs and SF₆ for the same amount of electronics production. Depending on the cleaning technology (i.e., remote or in-situ), the fraction released ranges usually from 2 to 5 per cent, but may reach up to 16 percent of the quantities of gas used. Recent atmospheric measurements imply that the average release rate may be closer to the upper end of this range.

Emissions reduction options

Some emission reduction goals have already been established in the semiconductor and LCD industries. Mitigation efforts in the semiconductor industry focus on process improvements/source reduction, alternative chemicals, capture and beneficial reuse, and destruction technologies. Some companies are reducing emissions by adopting alternatives to NF₃. Linde, Toshiba Matsushita Display, Samsung and LG have installed systems that generate fluorine (F₂) on-site at some of their LCD and semiconductor facilities, replacing the use of NF₃ and SF₆. The on-site systems could eliminate NF3 consumption. However, the implementation of these systems requires upfront costs that smaller LCD manufacturers find it difficult to support due to safety issues related to handling fluorine, a reactive and toxic material.

In Japan and Taiwan, hexafluorobutadiene (C₄F₆ or CF₂=CF-CF=CF₂) has already been tested in industry as a possible replacement as etching agent.

The use of remote plasma cleaning is an alternative technology that, by breaking NF₃ in a remote container and injecting only the active ingredient, fluorine, together with nitrogen, in the vacuum chamber, can reduce the fraction of gas released from 16 per cent to 2 per cent.

Production

A 2005 report by the global semiconductor industry states that C₂F₆ (a PFC already included in the Kyoto basket of gases) continues to be the primary chamber cleaning gas and currently makes up the majority of semiconductor PFC emissions. However, NF₃ is fast catching up with the use of C₂F₆ to both growth in total semiconductor manufacture (with estimated production increases of 15-17 per cent per annum) as well as displacement of older PFC technology for new production lines that use NF₃. Since 1992, when less than 100 tonnes of nitrogen trifluoride were produced, production grew to an estimated 4,000 tonnes in 2007 and is projected to increase significantly, reaching 8,000 tonnes per year by 2010 and this is expected to grow further Nitrogen trifluoride is mostly produced in Japan, the Republic of Korea, Taiwan and the United States of America.

Methodologies to estimate emissions

Methodologies to estimate NF₃ emissions in the electronics industry are available in the good practice guidance and the 2006 IPCC Guidelines.

References

Paper no 1.B: Australia. Views on the coverage of greenhouse gases. Submission to the AWG-LCA and AWG-KP. Available at http://unfccc.int/resource/docs/2008/awglca3/eng/misc02a01.pdf

Prachi Patel-Predd. 2008. Electronics Industry Changes the Climate with New Greenhouse Gas. Available at http://www.sciam.com/article.cfm?id=electronics-industry-contributes-new-greenhouse-gas

Prather, M J, and J. Hsu. 2008. NF3, the Greenhouse Gas Missing From Kyoto. Geophys. Res. Lett., 35. L12810, doi:10.1029/2008GL034542, p. 1

Reichardt, H, Frenzel, A and K. Schober. 2001. Environmentally friendly wafer production: NF₃ remote microwave plasma for chamber cleaning. Microelectronic Engineering 56. doi:10.1016/S0167-9317(00)00505-0.

Robson, J I; Gohar, L K, Hurley, M D, Shine, K P and Wallington.2006. Revised IR spectrum, radiative efficiency and global warming potential of nitrogen trifluoride. Geophys. Res. Lett., 33, L10817, doi:10.1029/2006GL026210.

Weiss, R F, Muhle, J, Salameh, P, and C. Harth. 2008. Nitrogen trifluoride in the global atmosphere. Geophys. Res. Lett., in press, October 1, 2008.

http://www.airproducts.com/markets/electronics/newsletter/solutionsupdatevol1.htm

http://www.thefreelibrary.com/Applied+Materials+Expands+Intellectual+Property+Portfolio+for+C4F6...-a084793307

4. Trifluoromethyl sulphur pentafluoride (SF₅CF₃)

Main applications: unknown

The concentration of trifluoromethyl sulphur pentafluoride in the atmosphere has been increasing, and some studies indicate that this is coupled with the increase of concentration of sulphur hexafluoride (SF₆). There are assumptions that, because it is closely chemically related to SF₆, it could originate as a breakdown product of (SF₆) in high voltage equipment, via the spark discharge reactions of (SF₆) with a few fluorocarbons.

Methodologies to estimate emissions

Emissions of Trifluoromethyl sulphur pentafluoride, when generated as by products from production of fluorinated compounds, could be estimated using high tier methodologies from the 2006 IPCC Guidelines. (chapter 3.10.2, volume 3)

References

IPCC. 2006. 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). Published: IGES, Japan. Available at http://www.ipcc-nggip.iges.or.jp/public/2006gl/index.html

Li Huang, Lili Zhu, Xunxi Pan, Jianliang Zhang, Bin Ouyang and Huiqi Hou. 2005. One potential source of the potent greenhouse gas SF₅CF₃: the reaction of SF₆ with fluorocarbon under discharge. In Atmospheric Environment.Volume 39, Issue 9, March 2005, Pages 1641-1653. Available at http://www.sciencedirect.com

Sturges, W T, Wallington, M D, Hurley, K P, Shine, K, Sihra, A, Engel, D E Oram, S A, Penkett, R, Mulvaney and C. A. M. Brenninkmeijer. 2000. Trifluoromethyl Sulfur Pentafluoride (SF₅CF₃) and Sulfur Hexafluoride (SF₆) from Dome Concordia. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. Available at http://cdiac.esd.ornl.gov/trends/otheratg/sturges/sturges.html

Sturges, W T, Wallington, T J, Hurley, M D, Shine, K, Sihra K P, Engel, A, Oram, D E, Penkett, S A, Mulvaney, R. and M. Brenninkmeijer. A Potent Greenhouse Gas Identified in the Atmosphere: SF₅CF₃. Available at http://www.sciencemag.org/cgi/content/abstract/289/5479/611

Tucket, R. 2006. Trifluoromethyl sulphur pentafluoride(SF₅CF₃): Atmospheric Chemistry and its environmental importance via the Green-house effect in Fluorine and the Environment By Alain Tressaud. Available at http://books.google.co.uk/books?id=-xYG7Fchbl4C

WMO. 2006. Scientific Assessment of Ozone Depletion: 2006 – Report no. 50. World Meteorological Organization. Global Ozone Research and Monitoring Project. Available at http://www.wmo.int/pages/prog/arep/gaw/ozone_2006/ozone_asst_report.html

5. Fluorinated ethers (HFE)

Other names

Hydrofluorinated ethers, Hydrofluoro ethers.

Main applications: solvents and cleaning

Potential applications: refrigerants, heat transfer fluids in refrigeration, foam blowing, plasma etching; industrial heat transfer fluids, fire suppressant and solvents.

The main sector in which fluorinated ethers have been used is in the electronics, metal, and precision cleaning industry, replacing solvents such as CFC-113, methyl chloroform, HCFC-141b, n-propyl bromide and, and to a lesser extent, HFC-43-10mee. The pure HFEs are limited in utility in cleaning applications due to their mild solvent strength. However, HFEs are also used in azeotropic blends with other solvents (such as alcohols and trans 1,2 dichloroethylene) and in co-solvent cleaning processes, giving them broader cleaning efficacy. Currently, the HFEs most widely used in industry as cleaning solvents are HFE-7200 (HFE-569sf2), HFE-7100 (HFE-449s1), HFE-7500 (3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2,2,2-trifluoromethyl-hexane) and HFE-7000 (HFE-347mcc3). Currently the amount of the use of these HFEs is estimated around thousand tones per year. Also, HFE-236fa can have a potential role as a solvent. The 2009 TEAP report listed HFEs as possible alternatives for replacement of HCFC and HFC solvents in specialized niche applications, but it is expected that their use will be limited due to high cost.

Another use of the fluorinated ethers is as a substitute for CFC-113 and HCFC-141b solvent in technical aerosols (group of pressurized products used to clean, maintain, fix, test, manufacture, disinfect, or apply lubricant and mould release agents to various types of equipment) in a number of industrial and commercial processes. Also for this application, the relatively higher costs of HFE in comparison to HCFC-141b may cause replacement difficult

Fluorinated ethers such as HFE 125, HFE-134, HFE-143a, HFE-227me, HFE-245mf and HFE-245mc have been identified as potential refrigerants based on properties such as thermal stability, cycle performance, flammability, toxicity and tropospheric lifetime. However, the role of HFEs as replacement of refrigerants such as HFCs will depend on the accommodation of their higher price (generally ten times higher than HFCs), and the competition from other alternatives such asthe unsaturated HFCs(also named HFOs). HFE-43-10pccc124 ((H-Galden 1040x), HFE-236ca12 ((HG-10) and HFE-338pcc13 ((HG-01) are used as heat transfer fluids in refrigeration systems.

An emerging application in which HFEs have the potential to replace HFCs is as a secondary refrigerant in refrigeration systems.

Since the 1950-60s, α-fluorinated ethers were used as fast-acting inhalation anaesthetics and anti-inflammatory agents (e.g. HFE-235da2–isoflurane and HFE-236ea2–desflurane).

Some fluorinated ethers have been identified, on the basis of thermal conductivity properties, as potential alternatives to HCFC-22 and HCFC-141b as foam blowing agents. Typical examples are HFE-347mcc3, HFE-347mmy, HFE-245mc, HFE-227me, and HFE-254cb2. HFE-245mf, HFE-245mc, HFE-254pc and HFE-356mec are particularly promising. However, it is not expected the use of HFEs in this application considering the availability of less expensive alternatives.

Also, HFEs including HFE-227me and CF(CF₃)CF₂OCHFCF₃ have been proposed for use as clean etching agents in semiconductor manufacture and some fluorinated ethers have been proposed for use as fire suppressants, such as H Galden 1040x and possibly
HFE-356mec3.

The IPCC/TEAP suggests that as a result of the relatively low GWPs of some HFEs, their use as a replacement for other gases would “significantly reduce” greenhouse gas emissions. However, they are currently more expensive to produce than HFCs that can be used for the same purposes, so far use is minimal, and future developments are difficult to forecast.

Emissions reduction options

There is little information available regarding the costs of HFE mitigation. Currently, HFEs use is concentrated in specialised high value sectors (such as precision cleaning) where the main alternatives are higher GWP fluorocarbons. There is therefore limited scope for mitigation.

Producers

Main producers of HFEs are in located in the United States of America and to some degree in the European Union, but not in Japan.

Methodologies to estimate emissions

HFE are potential substitutes of ODS and emissions may be estimated using methodologies comparable to those used for ODS substitutes. Methods are available in the 2006 IPCC Guidelines for specific uses of these substances such as heat fluids.

References

IPCC/TEAP. 2005. Special Report on Safeguarding the Ozone and the Global Climate System: Issues relating to hydrofluorocarbons and perfluorocarbons p. 391. Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

Frederic R L , Baptiste M, Jean- Pierre V and S Pazenok. 2008. Trifluoromethyl ethers - synthesis and properties of an unusual substituent. J. Org. Chem. 2008, 4, No. 13. doi:10.3762/bjoc.4.13

Paper no 1.B: Australia. Views on the coverage of greenhouse gases. Submission to the AWG-LCA and AWG-KP. Available at http://unfccc.int/resource/docs/2008/awglca3/eng/misc02a01.pdf

UNEP/TEAP. 2009. Assessment of Alternatives to HCFCs and HFCs and Update of the TEAP 2005 Supplement Report Data. Task Force Decision XX/8 Report. UNEP Technology and Economical Assessment Panel. Available at http://ozone.unep.org/Assessment_Panels/TEAP/Reports/TEAP_Reports/teap-may-2009-decisionXX-8-task-force-report.pdf

UNEP/TEAP. 2010. Assessment of HCFCs and environmentally sound alternatives; Scoping study on alternatives to HCFC refrigerants under high ambient temperature conditions. Task Force Decision XXI/9 Report. UNEP Technology and Economical Assessment Panel. Available at http://www.unep.ch/ozone/Assessment_Panels/TEAP/Reports/TEAP_Reports/teap-2010-progress-report-volume1-May2010.pdf

The Significant New Alternatives Policy (SNAP) Program of the US EPA. Available at http://www.epa.gov/ozone/snap/

http://www.freshpatents.com

http://www.wipo.int/pctdb/en/wo.jsp?IA=US1994006439&WO=1995001320&DISPLAY=DESC

http://www.wipo.int/pctdb/en/wo.jsp?IA=US2001044256&DISPLAY=CLAIMS

6. Perfluoropolyethers (PFPEs)

Other names

perfluoropolymethylisopropyl ethers (PFPMIE) are also named polyperfluoromethylisopropyl ethers, Fomblin HC or Galden.

* for PFPMIE (CF₃OCF(CF₃)CF₂OCF₂OCF₃)

Main applications: heat transfer fluids, cleaning and dermatologicalcosmetics

Potential application: fire extinguisher

Only one per-fluorpolyether is listed in the IPCC AR4: perfluoropolymethylisopropyl ether (PFPMIE). Reported uses for perfluoropolyethers as a chemical group include industrial heat transfer fluids, electronic reliability testing, metal and electronics cleaning, and lubricant applications. However, the majority of the cleaning industry have moved away from high-Ozone Depletion Potential (ODP) and/or high-GWP gases (e.g. CFC-113, methyl-chloroform, PFCs and PFPEs). Largely, this industry has adopted alternative technologies such as no-clean, aqueous and semi-aqueous cleaning; and solvents such as HFCs, HFEs, hydrocarbons and alcohols. Notwithstanding, certain specialty solvent applications (mainly precision cleaning) still require PFPEs as solvents owing to reliability, compatibility, stability and low toxicity. There is little information available regarding how large the PFPE share of this market is.

Another application for which PFPEs have been identified as chemically suitable is as a fire extinguisher. However, there is little evidence available that PFPEs are used for this purpose at present.

PFPMIE has been used as a dermatological and a cosmetic product, and as a heat transfer fluid and dielectric applications.

Methodologies to estimate emissions

Emissions for PFPEs used as transfer fluids and solvents may be estimated using the methodologies presented in the 2006 IPCC Guidelines.

References

Cora J. Young, Michael D. Hurley, Timothy J. Wallington, and Scott A. Mabury (2006) “Atmospheric Lifetime and Global Warming Potential of a Perfluoropolyether.” Environ. Sci. Technol., 2006, 40 (7), pp 2242–224

IPCC/TEAP. 2005. Special Report on Safeguarding the Ozone and the Global Climate System: Issues relating to hydrofluorocarbons and perfluorocarbons. p. 391. Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

Paper no 1.B: Australia. Views on the coverage of greenhouse gases. Submission to the AWG-LCA and AWG-KP. Available at http://unfccc.int/resource/docs/2008/awglca3/eng/misc02a01.pdf

7. Dimethylether (DME) (CH₃OCH₃)

Other names

Methoxymethane, DME, Wood ether, Dimethyl oxide, Demeon, Dymel A

Main applications: aerosol propellant and synthetic fuel

Dimethylether has been used as an aerosol propellant since the 1970s. In developed countries, 98 per cent of non-medical aerosols now use non-ozone-depleting, very low GWP propellants (hydrocarbons, dimethylether, CO₂ or nitrogen).

It is also used as a synthetic fuel that can be a substitute for liquefied petroleum gas (LPG), as a blended fuel in diesel or petrol engines, or reformed into hydrogen for fuel cells. Potential uses, in the development stage are power generation and petrochemical stocks. Several thousand tonnes are consumed annually for the production of dimethyl sulphate.

Production

Mostly from natural gas or coal as a synthetic fuel. May also be derived from many sources, including renewable materials (biomass, waste and agricultural products). Asia has the largest potential market for dimethylether as a domestic fuel. Most factories are in China. There are plans to construct new plants of dimethylether in Japan, Iran and New Guinea. Production capacity has grown exponentially from 20,000 million tonnes in 1993 to 545,000 million tonnes in 2006, and is forecasted to reach 11,317,000 million tonnes by 2012.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines.

References

The Catalyst Group, 2007, Global Dimethyl Ether Emerging Markets Available at http://www.aboutdme.org/EFIClient/files/ccLibraryFiles/Filename/000000000424/2007_DME_Seminar_9_Payne_CatalystGroup.pdf

http://sci-toys.com/ingredients/dimethyl_ether.html

http://www.aboutdme.org/index.asp?bid=275

http://www.biodme.eu

8. Methyl chloroform (CH₃CCl₃)

Other names

1,1,1-Trichloroethane, TCA, Chlorothene

Main applications: solvent, cleaning, lubricant and chemical processing

Together with CFC-113, methyl chloroform was one of the most used solvents and degreaser in industry (metal cleaning, electronics cleaning, and precision cleaning.). It was also used as:

· as a component of aerosols formulations, particurlarly for brake cleaning;

· as a coolant and lubricant in metal cutting oils;

· component of adhesives;

· in the manufacture of vinylidene chloride;

· the standard cleaner for photographic film (movie/slide/negatives, etc).

It was registered as a pesticide and used in adhesives, aerosols, coatings, chemical process intermediates and in laboratory and analytical applications (Petroleum analyses).

This compound is included as a controlled substance in the Montreal Protocol annexes. Reporting to this Protocol have shown that production of methyl chloroform has gone to a minimum level, and analyses made by the Science Panel under the MP have shown that concentrations of this chemical in the atmosphere are rapidly declining to virtually zero emissions.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

IPCC/TEAP. 2005. Special Report on Safeguarding the Ozone and the Global Climate System. p. 391. Available at Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

UNEP. 2008. May 2008 Report of the Technology and Economic Assessment Panel. Volume 1. Progress Report, 2008. United Nations Environment Program (UNEP). Technology and Economic Assessment Panel. Available at http://ozone.unep.org/Assessment_Panels/TEAP/Reports/TEAP_Reports/Teap_progress_report_May2008.pdf

WMO. 2006. Scientific Assessment of Ozone Depletion: 2006 – Report no. 50. World Meteorological Organization. Global Ozone Research and Monitoring Project. Available at http://www.wmo.int/pages/prog/arep/gaw/ozone_2006/ozone_asst_report.html

http://www.scorecard.org/chemical-profiles/html/methyl_chloroform.html

http://www.hsia.org/white_papers/111tri wp.html

9. Methylene chloride (CH₂Cl₂)

Other names

Dichloromethane, R-30, Freon 30, Methylene dichloride, Solmethine, Narkotil, Solaesthin, Di-clo, DCM, UN 1593, MDC

Main applications: blowing agent polyurethane foams, solvent and extraction of oils.

Methylene chloride was used, together with HCFCs (transitionally), HFC and CO₂, as a blowing agent of foams. Has substituted CFC-11 for flexible low density polyurethane (PU) foams in developing countries.

Together with trichloroethylene and perchloroethylene methylene chloride has been used as a primary in-kind substitute for 1,1,1-trichloroethane and carbon tetrachloride.

Other reported uses of methylene chloride are:

· aerosol propellant and solvent;

· paint strippers and removers;

· carrier solvent in adhesives, as an aerosols;

· pesticide products;

· manufacture of photographic film;

· extraction solvent for spice oleoresins, hops, and for the removal of caffeine from coffee.

It is believed that the quantities used and emitted are relatively small, considering that methylene chloride is toxic to a certain degree.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

IPCC/TEAP. 2005. Special Report on Safeguarding the Ozone and the Global Climate System: Issues relating to hydrofluorocarbons and perfluorocarbons. p. 391. Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

The Significant New Alternatives Policy (SNAP) Program of the US-EPA. Available at http://www.epa.gov/ozone/snap/

The US-EPAs Technology Transfer Network Air Toxics Web Site. Available at http://www.epa.gov/ttn/atw/hlthef/methylen.html

The US Department of Health and Human Services - Agency for Toxic Substances and Disease Registry. Available at http://www.atsdr.cdc.gov/substances/methylene_chloride/index.html

The Australian National Pollutant Inventory (NPI). Dichloromethane fact sheet. Available at http://www.npi.gov.au/database/substance-info/profiles/34.html

10. Methyl chloride (CH₃Cl)

Other names

Chloromethane, R-40, Freon 40, Artic, UN 1063

Main applications: chemical processing, solvent, aerosol propellant and natural processes

Chloromethane is used almost entirely as a chemical intermediate to make other chloromethanes, silicone intermediates, butyl rubber, pesticides, quaternary amines and surfactants and as a methylation reactant for various other processes. It is also used as industrial solvent and cleaner; heat transfer medium in fire extinguishing, aerosol propellant, extractant for greases, oils and resins, catalyst carrier in low-temperature polymerization, as a propellant and blowing agent in polystyrene foam production and as a as a fluid for thermometric and thermostatic equipment. Uses such as an anaesthetic and refrigerant were discontinued due to its toxicity and flammability.

Together with methyl bromide (CH₃ Br), it is one of the naturally occurring ozone-depleting substances (ODS). The large majority of emissions (90-99 per cent) are produced naturally in the oceans, from biomass burning in grasslands and forested areas, vegetation in tropical forests, and degradation of vegetal materials. The oceanic source estimate, once understood as the major source, has been revised downward.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

IPCC/TEAP. 2005. Special Report on Safeguarding the Ozone and the Global Climate System: Issues relating to hydrofluorocarbons and perfluorocarbons. p. 391. Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

http://www.inchem.org/documents/sids/sids/CLMETHANE.pdf

WMO. 2006. Scientific Assessment of Ozone Depletion: 2006 – Report no. 50. World Meteorological Organization. Global Ozone Research and Monitoring Project. Available at http://www.wmo.int/pages/prog/arep/gaw/ozone_2006/ozone_asst_report.html

http://www.epa.gov/ttn/atw/hlthef/methylch.html

11. Dibromomethane (CH₂Br₂)

Other names

Methylene bromide, Methylene dibromide, Methyl dibromide, DBM, MDB, Refrigerant-30B2, UN 2664

Main applications:solvent, gage fluid, plasma etching, pesticide, fire retardant and natural sources

Naturally, dibromomethane is a primary emission product of macroalgae, in particular brown and green (e.g. Fucales sargassum, Laminariales lamanaria), occurring along beaches.

Dibromomethane finds limited use in chemical synthesis, as a solvent, and as a gage fluid. It is also used with SiCl₄+Cl₂ for plasma etching, replacing HBr. It is also a pesticide intermediate, and an ingredient (limited use) in fire extinguishing fluid (fire retardant when added into the polymers). It can be released to the atmosphere as a by-product of tap water disinfection.

Production

Natural emission sources are estimated between 90 to 99 per cent of total global emissions and anthropogenic production represents a minor contributor.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

Philip H H, 1989, Handbook of environmental fate and exposure data for organic chemicals CRF Press. Available at http://books.google.co.uk/books?id=HdhohbQrg8IC

http://www.ewg.org/tapwater/contaminants/contaminant.php?contamcode=2408

http://www.speclab.com/compound/c74953.htm

http://www.made-in-china.com/showroom/cnzoutong/offer-detailMqbxmXyvAEYO/Sell-Dibromomethane.html

http://www.wipo.int/pctdb/en/wo.jsp?wo=2005017961

http://www.cheresources.com/invision/index.php?s=374e317a53dbea958e71946131340e8c&showtopic=6159&pid=20467&st=0�entry20467

12. Bromodifluoromethane (CHBrF₂)

Other names

Difluorobromomethane, Halon 1201, HBFC-22B1, FC-22B1, R-22B1, FM-100

Main applications: Bromodifluoromethane is used as a fire extinguisher-suppressant, particularly in hand-held fire extinguishers.

Bromodifluoromethane is included as a controlled substance in the Montreal Protocol annexes, and analyses made by the Science Panel under the MP have shown that concentrations of this chemical in the atmosphere have so far not reached significant levels. There is also no evidence that this chemical is being produced as a replacement for any conventional use.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

http://en.wikipedia.org/wiki/Bromodifluoromethane

http://www.wipo.int/pctdb/en/wo.jsp?wo=1991005585

http://www.freepatentsonline.com/EP0383443.html

13. Trifluoroiodomethane (CF₃I)

Other names

Trifluoromethyl iodide, Iodotrifluoromethane, Monoiodotrifluoromethane, Trifluoromethyl iodide, Perfluoromethyl iodide, Freon 13T1

Main application: reagent

Potential applications: plasma etching, fire suppressant and medical sterilizer

Trifluoroiodomethane is referred for plasma etching in the patent literature, and its composition makes potential use as refrigerants. It is used as a reagent in the rhodium-catalyzed a-trifluoromethylation of a,b-unsaturated ketones. It has being considered as a fire suppressant as a replacement for halon-1301 in unoccupied spaces, and as a flooding agent for in-flight aircraft and electronic equipment fires. It also has been proposed for use in blends with CO₂ and ethylene oxide as a medical sterilizer, as a substitute for CFCs and HCFCs. Information from the Montreal Protocol Technology Panel is that no significant use is foreseen so far. This substance might in the future be controlled under the Montreal Protocol due to a small ODP value (from 0.011 to 0.018 dependent on where emissions take place) in spite of being a short lived substance.

Methodologies to estimate emissions

No specific methodologies are available in the IPCC guidelines, although general methodologies may be used when the substance is used as a solvent.

References

Clewell, H. and G. Lawrence. 1999. Position Paper for Trifluoroiodomethane (CF₃I). U.S. Environmental Protection Agency, Office of Air and Radiation, Stratospheric Protection Division. Available at http://www.concentric.net/~cf3i/pospaper/posp.htm

Dodd, D E ; Vinegar A. 1978. Cardiac sensitization testing of the halon replacement candidates trifluoroiodomethane (CF₃I) and 1,1,2,2,3,3,3-heptafluoro-1-iodopropane (C₃F₇I), Drug and chemical toxicology ISSN 0148-0545. Available at http://cat.inist.fr/?aModele=afficheN&cpsidt=2251203

Dodd, DE, Leahy, H F; Feldmann, M L; Vinegar, . and J. H. English. 1998. Reproductive Toxicity Screen of Trifluoroiodomethane (CF31) in Sprague- Dawley Rats. Available at http://www.stormingmedia.us/03/0347/A034763.html

The Significant New Alternatives Policy (SNAP) Program of the US EPA. Available at http://www.epa.gov/ozone/snap/

http://www.freepatentsonline.com/6270689.html

http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/171441

EXISTING STOCKS AND POTENTIAL EMISSIONS OF CFCs AND HCFCs

The estimate of the quantities of existing banks - banked chemicals in equipment and products - of CFCs and HCFCs is well documented in the following reports:

IPCC/TEAP special report on "Safeguarding the Ozone Layer and the Global Climate System: Issues related to hydrofluorocarbons and perfluorocarbons". This report was developed in response to invitations by the UNFCCC and the Montreal Protocol on Substances that Deplete the Ozone Layer to prepare a balanced scientific, technical and policy relevant report regarding alternatives to ozone-depleting substances (ODSs) that affect the global climate system. It has been prepared by the IPCC and the Technology and Economic Assessment Panel (TEAP)of the Montreal Protocol.

Available at http://www.ipcc.ch/pdf/presentations/briefing-bonn-2005-05/safeguarding-ozone-layer.pdf

“Supplement to the IPCC/TEAP report”. While the Special Report focused on the climate benefits of such actions by presenting the results in terms of GHG units of measure (CO₂eq), the Supplement Report presents the Mitigation Scenario emission reduction in terms of ozone units of measure (ODP tonnes).

Available at http://ozone.unep.org/teap/Reports/TEAP_Reports/teap-supplement-ippc-teap-report-nov2005.pdf.

The information presented in this page is a short compilation from both reports, in particular the IPCC/TEAP special report, and it does not intend to replace the reading and analysis of the original documents.

The IPCC/TEAP Special Report notes that the UNFCCC addresses anthropogenic emissions by sources, and removals by sinks of all GHG not controlled by the Montreal Protocol, while the Montreal Protocol, on the other hand, controls not the emission but rather the production and consumption of ODSs. Thus, the emissions due to releases of CFCs and HCFCs present in banks are not covered neither in the Montreal Protocol nor in the UNFCCC. Banks are the total amount of substances contained in existing equipment, chemical stockpiles, foams and other products not yet released to the atmosphere. The build up of banks will, in the absence of bank management measures, significantly determine future emissions. The following table provides a synthesis of the quantities estimated in banks for 2002 and predictions for 2015.

The banks stored in equipment and foams may leak during the use phase of the products they are part of and at the end of the product life cycle, if they are not recovered or destroyed. In 2002 the largest bank of ODS (CFCs) was in foam products (almost 3,000 kt), and this will remain the case between 2002 and 2015. Banks of halons are also important. This will remain the case until 2015, although the size of the bank is expected to decrease. Banks of ODS substances in refrigeration and air conditioning are relatively small (compared to the others mentioned above) and will be much smaller in the year 2015, mainly due to a decrease in the CFC banks.

The following tables summarise the information presented in the IPCC/TEAP special report and in the TEAP supplement report. The first table refers to the estimates of CFC and HCFC in banks for the year 2002 and projections for 2015 according to the Business as Usual Scenario (BAU)⁴. The second table summarizes the emission estimates made in accordance with the bottom-up approach. In both tables annual values are provided in mass of gas (tonnes) and in CO₂ eq ⁵.

Total CFC and HCFC stored in banks in 2002 and projections for 2015 (BAU scenario), expressed in mass units (kt) and CO₂ eq (Gt)

Sector	Gas	2002		BAU 2015
		Banks (kt)	Gt CO2eq	Banks (kt)	Gt CO2eq
Refrigeration, A.C. & M.A.C.	CFC	563	5.65	104	1.0
	HCFC	1,509	2.60	1,792	3.16
	Total	2,072	8.25	1,896	4.16
Foams	CFC	1,858	10.03	1,305	7.29
	HCFC	1,126	1.23	1,502	1.70
	Total	2,984	11.26	2,807	8.99
Other	CFC	0	0	2	-
	HCFC	23	0.01	22	-
	Total	23	0.01	24	-
Total	CFC	2,421	15.68	1,411	8.29
	HCFC	2,658	3.84	3,316	4.86
	Total	5,079	19.52	4,727	13.15

Emissions of CFCs and HCFCs from banks, expressed in mass units (kt) and CO₂ eq (Gt)

Sector	Gas	2002		BAU 2015
		Banks (kt)	Gt CO2 eq	Banks (kt)	Gt CO2 eq eq
Refrigeration, A.C. & M.A.C.	CFC	144	1.47	24	0.24
	HCFC	236	0.41	455	0.80
	Total	380	1.88	479	1.04
Foams	CFC	22	0.12	16	0.09
	HCFC	24	0.03	21	0.02
	Total	46	0.15	37	0.11
Other	CFC	8	0.00	2	0.00
	HCFC	11	0.00	16	0.00
	Total	19	0.00	18	0.00
Total	CFC	174	1.59	42	0.33
	HCFC	271	0.44	492	0.82
	Total	445	2.03	534	1.15

⁴According to the Business-As-Usual(BAU) scenario defined in the Special Report.

⁵According to the Business-As-Usual(BAU) scenario defined in the Special Report.

Last updated 27 July 2010