


Publications
January, 2001
ISBN: 0 6425 47319
1 This Chapter summarises the current position in Australia and internationally on the transition from the traditional and high ozone depleting potential (ODP) ozone depleting substances (ODS), through the so-called transitional substances such as HCFCs with generally lower ODPs, to alternatives with very low or zero ODPs such as the synthetic gases like HFCs or not-in-kind (NIK) alternatives like hydrocarbons and ammonia. The focus is on presenting the main technical considerations in non-technical terms.16
1.1 An overview of the leading technical issues is followed by consideration of the particular technical issues relevant to the major ODS products or sectors.
1.2 ODS have been, and continue to be, used in a range of different activities and industries. By the 1980's their use was widespread in aerosols (propellant), refrigeration and air conditioning (refrigerant), foam manufacture (blowing agent), fire protection (suppressant) and agriculture/quarantine (fumigant). Specialist uses were also important as cleaning agents and solvents.
1.3 Developments in the knowledge and science of ozone depletion culminated in international efforts to reverse the rate of growth in human-generated ODS emissions in the atmosphere. The focus of the Montreal Protocol is on progressively eliminating the production, supply and consumption of ODS. That is to eliminate the use of ODS and hence the source of emissions.
1.4 The main technical challenge has been to develop and introduce alternative technologies and products which are not ozone depleting. There has also been an emphasis on improving the overall stewardship of ODS production, use and operation to make the reducing supplies of ODS go further and to minimise ODS escaping into the atmosphere. This has led to major improvements in production, distribution, application or use, handling and recovery of ODS. Important in this have been improved equipment and systems design, minimum application or charge levels and operational improvements to minimise fugitive emissions (eg leakage containment) together with recovery/recycling/reclaim during installation, maintenance and decommissioning of equipment.
1.5 The major challenge to developing alternatives has been to find substances and/or technologies which carry out the functions of those they are replacing without significant penalties in terms of environmental change, public health and safety and cost. Usually some compromises are necessary.
1.6 In this context considerations relating to technical performance also have to be considered in terms of toxicity, flammability and environmental impacts. While the older, well established ODS such as CFCs were used because they were generally benign in terms of toxicity and flammability (indeed they replaced hydrocarbons and ammonia in many refrigeration applications partly for these reasons) this is not always the case (eg methyl bromide is very toxic). Accordingly, generalisations about each successive or proposed alternative being an improvement on those that proceeded it in terms of toxicity and flammability as well as in operational performance can be an oversimplification.
1.7 This caution is also very applicable in respect to the environmental impacts of alternatives, since a lower ODP under ozone and Montreal Protocol objectives, may not necessarily have a lower greenhouse warming potential (GWP) in terms of climate change and Kyoto Protocol considerations.17 This interaction of ozone depletion and global warming considerations has increasingly influenced the search for alternatives to ODS. In recent years more comprehensive concepts of assessing environmental impacts have gained importance. These incorporate the direct impacts on the atmosphere of emissions (ie those from equipment or practices which emit ODS to air) with indirect impacts such as energy efficiency in the operation of equipment and usually extending throughout the production and supply chain to the end of equipment life.18
1.8 These life cycle or cradle to grave approaches to assessing the environmental impacts of alternatives to ODS, including the transitional lower ODP HCFC, are starting to play a role in the development of integrated policies and measures to deal with ozone depletion and global warming.
1.9 They have also placed new emphasis on the two major streams of research and commercialisation of alternatives and provided new ways of assessing their relative environmental merits or other impacts.
1.10 The first line of alternative development concerns in-kind replacements. That is new substances or mixtures of substances based on the same broad chemical family as the ODS they are designed to replace. The best know progression of in-kind replacements is that from CFCs, through HCFCs to HFCs in the refrigeration sector. (In this example HFCs have zero ODPs but have high GWPs). The very considerable research and production scale up in this group is largely funded and marketed by the large multinational chemical companies who manufactured the ODS in wide use by the late 1980s.
1.11 The second broad avenue for replacements or alternatives are the not-in-kind (NIK) solutions which besides having zero ODPs have low or negligible GWPs. This group includes the hydrocarbons (HC) as well as other 'natural' products such as ammonia and carbon dioxide.
1.12 There are other technologies and solutions being developed but generally these also relate to the delivery use or application of one or both of these two broad avenues. Each tends to have different industry sectors championing it and promoting research, production, distribution and marketing. Each is seeking to develop new products for specific applications and bring them successfully to market and/or have them approved for wider use. The competition is global and very intense as it will determine the future position and share of the major players in the marketplace in the longer term. Additionally, the environmental outcomes from these approaches are still be actively debated.
1.13 Some of the key considerations in the development, commercialisation and market (and government) acceptance of alternative to ODS include:
1.14 Most of the research and development of the chemical alternatives to ODS and the major items of equipment or processes utilising these chemical alternatives in conducted overseas. Australia has no production of fluorocarbon chemical but is a producer of LPG and other chemicals associated with not-in-kind solutions.
1.15 In Australia and other developed countries the consumption of the main ODS were phased-out prior to 1996 (CFCs, halons, carbon tetrachloride and methyl chloroform) with alternatives been found and on the market before the final phase out date. Many of the alternatives involved interim or transitional use of ODS with lower ODP ratings in order to allow sufficient time for ozone benign substances, equipment and technologies to be developed and introduced without excessive cost or disruption. Some limited essential uses were also allowed in the change over period (eg CFCs for MDIs for certain respiratory diseases). Alternatively some critical uses were permitted to draw on managed stockpiles of ODS materials recovered from decommissioned or converted equipment (eg. halons for certain defence, aviation and shipping uses).
1.16 The present focus is therefore very much on finding alternatives for the interim substances (predominantly HCFCs) and new ODS brought under the ambit of the Protocol and the OPA (eg. methyl bromide).
1.17 As at mid-2000 the two most sensitive areas identified in terms of alternatives are for polyurethane foaming agents (HCFCs) and for some fumigation purposes (methyl bromide). In both these cases there are questions as to whether alternatives which are technically suited will be available ahead of supply constraints associated with the relevant phase-out timetable. Work is also progressing on findings and introducing alternatives in the few remaining essential or critical use categories such as MDIs and specials uses of halon 1301.
1.18 The following sections summarise the main technical issues in the major sectors:
1.19 The one commercial and industrial activity in Australia which has not substantively taken up alternatives to HCFCs is the manufacture of rigid polyurethane insulating foams, where HCFC-141b is still relied upon.19 Some industry sources claim that existing alternatives (eg. water and HCs) are unable to produce foam with adequate insulating properties for some applications, although more viable substitutes are expected to emerge within five years and are currently used overseas. Demand for HCFCs for the manufacture of foam has expanded substantially in recent years to accommodate high rates of growth in the consumer market. HFC 245fa and HFC 365mfc have emerged as further alternatives.20
1.20 The major agricultural activity for which alternative substances are not readily available is treating soil used to produce strawberry runners. In this case, no single substance can effectively replicate the overall effects of methyl bromide. Because individual alternatives address only part of the total requirements of horticultural producers, a shift away from methyl bromide requires that businesses adopt a broader and generally more costly range of measures for effective soil treatment including pest diagnostics and narrow spectrum pesticides.
1.21 HCFCs used in refrigeration and air conditioning equipment may be released into the atmosphere through normal equipment operation as a result of leaking joints and seals in a substantial proportion of existing capital stock. Added to this is the scope for emission through routine servicing particularly if applied by inexpert trades people and through the deliberate venting of material, inappropriate equipment disposal methods or industrial accidents.
1.22 Industrial cleaning and other activities using HCFCs generally take place in an open or non-hermetic environment as does the application of methyl bromide in horticulture in general. This results in relatively high emission rates. Metered dose medical inhalers produce very high emission rates upon use.
1.23 In the manufacture of rigid polyurethane foam, some industry sources claim HCFC- 141b is largely encapsulated in the product as part of a 'closed cell' production technique and emission rates are therefore relatively low. However, all ODS used in this way will eventually leak to the atmosphere. Most portable and fixed fire suppression systems also record relatively low levels of leakage except in the event that they are activated.
1.24 Refrigeration is the largest of the industry sectors still dependant on ODS. It has four major component sub-sectors: the food cold chain from production through transports/distribution and retail to the home; industrial refrigeration; stationary air conditioning; and mobile air-conditioning.
1.25 The phase-out of the consumption of bulk CFCs (the traditional refrigerant) was completed on or ahead of the Montreal Protocol schedule by the end of 1995. Alternatives to these refrigerants in existing and new equipment varied according to specific end use, but generally followed a pattern of moving to HCFC-22 and/or blends of HCFCs until HFC, blends/mixtures of HFC and non-fluorocarbon solutions became commercially available.
1.26 There are now accepted and readily available HCFCs and HFC alternatives for all major applications. The industry believes that the timeframe for the phasing-out of consumption of bulk HCFCs will be achieved. HFC alternatives particularly, HFC-134a and HFC blends in the ASHRAE 400 series are available. Also under consideration are not-in-kind refrigerants (particularly hydrocarbons) and secondary loop systems where the primary refrigerant (typically ammonia) in a plant room or remote location is isolated from the secondary refrigerant circulating through the main system usually in public areas such as supermarkets and large building.
1.27 Hydrocarbon options are still predominately for smaller charge domestic refrigerators and for large industrial complexes, partly because of Australian Standards, building and occupational health and safety codes, as well as the lack of equipment carrying manufacturers' warrantees as being designed and approved for their use. However, in Europe the use of hydrocarbon alternatives and purpose built equipment and components is more prevalent.
1.28 Most of the refrigerant alternatives have been developed for vapour compression cycle systems as other refrigerant cycle systems are not expected to be developed to the stage where they achieve significant market penetration for 10-20 years. The vapour compression cycle still provides the most straight foreword, efficient and cost effective refrigeration using fluorocarbons (both HCFCs and HFCs), ammonia, hydrocarbons and water/heat transfer fluids.
1.29 Refrigeration and air conditioning equipment tends to have long life cycles ranging from 10-15 years for domestic units, 15-20 years for core plant in commercial uses such as supermarkets and 30 years or more for large industrial/office buildings. Accordingly, recently installed HCFC refrigeration and air conditioning units may have the major part of their normal life span ahead of them before they are likely to be replaced with ozone benign alternatives.
1.30 Because of its size, the improvements in design, engineering and overall product stewardship of ODS and equipment has been of particular importance in the refrigeration sector. This has reduced refrigerant demand through smaller refrigerant charges, leak reduction, recovery, recycling and reclaim practices throughout the equipment's life span. Codes of practice and accreditation for Montreal Protocol controlled substances, together with an industry refrigerant reclaim program, have been important in this respect and could be further extended into the HCF refrigerants which are ozone benign but have relatively high GWP ratings.
1.31 The available in-kind alternatives (both HCFCs and HFCs) have progressively delivered energy efficiency improvements (although only in certain areas) and concepts like LCCP are of increasing interest. Besides energy efficiency and technical performance characteristics, toxicity and safety considerations, direct and indirect investment costs and Australian codes and standards influence decisions as to the choice of alternatives.
1.32 However, on balance the refrigeration sector is managing the current ODS phase-out and transition processes and is not experiencing significant technical issues in the process.
1.33 The phase-out of ODS in aerosol products has been largely completed. CFC in aerosols was phased-out in Australia well in advance of the Montreal Protocol timetable and most aerosols have moved to non-ODS options especially hydrocarbons. There are no significant technical difficulties in achieving a complete phase-out for most of the remaining few CFC or HCFC uses.
1.34 The one major exception is in respect to metered dose inhalers (MDI) for medical use in the treatment of asthma and respiratory disease. An international and national transition strategy is well advanced to phasing out ODS in MDI applications by 2005 in developed countries. Current indications are that this will be achieved for at least the great bulk of MDI with HFC 134 a and HFC-227ea being the alternative propellants.
1.35 Halons were established as the fire suppressant of choice in the fire protection industry, but were a priority for early phase-out due to their high ODP rating. In Australia this complex logistical and technical task was achieved well within the Montreal Protocol time scale with a managed stockpile or halon bank from decommissioned systems and equipment available to supply Protocol approved essential uses, where satisfactory alternatives have not been found or approved. These essential uses, trade in halons and their distribution are strictly monitored and controlled under the Protocol. In Australia, a Halon Management Strategy was released in February this year to met our international obligations to manage stocks of recovered and/or reclaimed halon for essential use purposes.
1.36 While a wide variety of alternatives have been developed, none of them cover the broad spectrum of applications met by halon 1211 and particularly by halon 1301. It is the latter halon which is associated with the management of existing stocks to supply essential uses in defence, aviation, shipping and in a limited number of other high risk situations.
1.37 The search for alternatives for halons has encouraged a range of new engineering systems and approaches, the majority of which have zero ODP although two alternatives (HFCs, carbon dioxide) are greenhouse gases.21 These approaches include changed work practices to minimise emissions except in case of fire, systems based on HFCs, carbon dioxide, mixtures of gases, water/water mist and blends of HCFCs.
1.38 In developing and assessing alternatives for halons (and for HCFCs) the key technical issues concern:
1.39 The current indications are that the Montreal Protocol timetable to 2030 for managing current halon stocks for essential uses and developing and introducing non-ODS replacements is on track. Alternatives for the limited essential uses for special applications presents the major challenge in Australia, as in other developed countries.
1.40 For most foam blowing, alternatives to the previously used blowing agents (predominantly CFCs and HCFCs) have been developed and adopted. The replacement blowing agents now used are primarily carbon dioxide, hydrocarbons and water-based agents. In future, fluorocarbon alternatives (HFCs) are expected to be limited to a limited number of applications currently using HCFCs (or CFCs in developing countries) particularly closed cell thermal insulation foams (polyurethane foam). Even in most of these applications some polyurethane foam blowers are using or will move to hydrocarbons, water and carbon dioxide. Industry has raised the availability of HFCs as replacements for HCFCs, as these substances are being phased-out, as an issue requiring attention.
1.41 Importantly, HCFCs and their replacement HFCs produce thermally efficient foams for insulation purposes, especially where space is a consideration. This contribution to energy efficiency is contributing to the demand for HCFC and HFC blowing agents while the relatively high GWP of the main HCFC agent (HCFC-141b) is leading to regulatory pressure to phase-out its use in Europe and North America over the next three years. This is expected to place pressure on access to the ozone benign HFC replacements (HFC-245fa and HFC-365mfc) which are not expected to reach commercial production in Europe and North America until 2005.
1.42 Other technical factors to be considered in selection of alternative foam agent options include safety and occupational health considerations as well as related building and workplace standards. Also the capital investment required to use some flammable alternatives to meet local requirements and standards may be prohibitive for smaller businesses.
1.43 While there is uncertainty in Australia about whether sufficient HCFC-141b will be accessible under the HCFC licence and quota regime to meet possible demand until alternative HFC agents are introduced, industry is considering its options through a review of technical factors in the light of more accurate forecasts and analysis.
1.44 The main ODS used in soil fumigation in horticulture and for quarantine and pre-shipment (QPS) purposes is methyl bromide. Methyl bromide for soil fumigation purposes (predominately in horticulture) is to be phased-out under the Montreal Protocol timetable by January 2005, while its use for QPS is reportable, but not yet subject to a planned phase-out regime. In neither of these major applications have single alternatives been identified which combine methyl bromide's technical efficiency across such a broad range of geographic and physical conditions to treat such a wide variety of pests and diseases.
1.45 By reason of their function, methyl bromide and its alternative fumigants are toxic and so replacement chemicals will require appropriate registration and approval before they can be widely used. Similarly, quarantine authorities have to approve alternatives for QPS before they can be effectively used with internationally traded commodities.
1.46 While no single substance has yet been identified which can substitute for methyl bromide across all its wide range of uses, alternatives have been identified for over 90% of these uses. In many cases these involve revised and integrated management practices using a combination of chemical and non-chemical products for different aspects of pest and disease control tailored for specific sites or situations. This is a much more complex process than the application of a single broad spectrum gas for virtually all situations.
1.47 It is made more complex by the dispersed nature of the horticultural industry both geographically and in terms of the prevalence of small and medium business enterprises. Transition from methyl bromide to alternatives in soil fumigation requires considerable research demonstration and training infrastructure.
1.48 All of these technical and related logistical factors have contributed to concerns that phase-out of all horticultural uses of methyl bromide will not be achieved by December 2004 - or at least not without the prospect of severe dislocation, disruption and cost in these regionally important industries. These are being addressed under the National Methyl Bromide Response Strategy - Horticultural Uses Part 1.
1.49 Similar considerations may apply to QPS uses which are considered unlikely to remain outside the Protocol's control and phase-out mechanisms for much longer.