This situation is therefore called “open loop - same primary route”. Figure 31 illustrates this schematically. Figure 31 “Open loop - same primary route” recycling: Waste or the end-of-life product from the first system (light blue) is collected and recycled/pre-treated (green) and brought to use in OTHER systems (dark blue), but is replacing the SAME primary route of its first life cycle. 14.3.2.2 Open loop - different primary route (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) The other sub-type of open-loop recycling, here referred to as “open loop - different primary route”, is where the secondary good replaces a different kind of material, energy or part while with the same or very similar function. An example is the incineration of postconsumer plastics with energy-recovery as electricity and use of the electricity in other applications


An example is the incineration of postconsumer plastics with energy-recovery as electricity and use of the electricity in other applications. The criteria for identifying whether a secondary good is replacing the same or a different primary route and material, energy or part is not always straightforward and gradually different interim cases exist. Schematically the “open loop – different primary route” recycling is shown in Figure 32. Extraction1 Material production1 Assembly1 Use1 Disposal1 Recycling Disposal2 Use2 Assembly2

European Commission – JRC, ILCD Handbook: General Guide for LCA (2010)


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Figure 32 “Open loop - different primary route” recycling: Waste or the end-of-life product from the first system (light blue) is collected and recycled/pre-treated (green) and brought to use in another system (dark blue), replacing a different primary production route. The open-loop recycling can in addition be anonymous in the sense that it is unknown (or exceedingly laborious to find out in practice) in which one or many system(s) the secondary good will be used (e.g. in case of electronic end-of-life product recycling in third countries). This causes additional difficulties in pinpointing the superseded processes in substitution. Often however, the one or many uses of the secondary good are known or can be sufficiently identified and quantified


14.4 Recycling in attributional modelling (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) 14.4.1 Detailed aspects of attributional modelling of recycling (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) 14.4.1.1 Introduction (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) The following main questions come up when modelling recycling in attributional modelling:  Where to draw the system boundary between the first and subsequent life cycles?, and  How to apply the ILCD two-step allocation procedure to these cases? The following information is required for answering these questions:  The market value of the waste or end-of-life product,  If the market value is below zero: Is there any valuable secondary good generated during treatment and if so in which processing step?, and  In any case: What are its physical characteristics and market value? The two cases of market value above and below zero need to be differentiated, as explained below: Extraction1 Material


and  In any case: What are its physical characteristics and market value? The two cases of market value above and below zero need to be differentiated, as explained below: Extraction1 Material production1 Assembly1 Use1 Disposal1 Recycling Extraction2 Material production2 Assembly2 Use2 Disposal2


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery 14.4.1.2 Market value of waste / end-of-life product is above zero, i.e. it is a co-product (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) Introduction If the market value of the waste / end-of-life product at its point of origin is above zero, in LCA perspective it is a co-product and the multifunctionality is to be solved by allocation. This is done applying the two-step procedure as detailed in chapter 7.9.3. As a special step, the true co-producing process is to be identified: this is that process step that has produced a product that is technically most similar to the waste / end-of-life product


As a special step, the true co-producing process is to be identified: this is that process step that has produced a product that is technically most similar to the waste / end-of-life product. The case of recycling is insofar different from the general case of multifunctionality, as the secondary good is not only a co-function of the system but itself is again and again recycled (while each time at lower amounts and/or quality, considering losses of each loop). We have hence many co-products, respectively a higher amount of secondary good uses than the amount available after the first recycling round. When aiming at identifying an inventory for the secondary good this is to be considered. Applying strictly attributional modelling, allocating by physical causality, these differently often recycled secondary goods have different inventories: some have only had e.g. one preceding recycling round, others e.g. 10


one preceding recycling round, others e.g. 10. To come to an average inventory, the inventories of the different amounts of differently often recycled secondary good are to be integrated and averaged”. This is required in practice, as the number of cycles a secondary good already has made typically cannot be measured and also as typical questions relate to the average product, not the specific cycle. First step: Total amount of uses When an end-of-life product is recycled, some fraction of the original material, parts or energy is obtained as secondary good and incorporated into a new product. If the product made from this secondary good is itself recycled, a smaller fraction of the original material, part, or energy is again obtained and incorporated into a third product. Given the recyclability and losses during recycling, the shares of the differently often recycled secondary goods in the market can be calculated


Given the recyclability and losses during recycling, the shares of the differently often recycled secondary goods in the market can be calculated. This can be summed up to represent the total amount of one unit of material that effectively has been used, once all material is lost after in theory indefinite loops of recycling: This total amount of use "U" is the sum of the amount of primary use "p" plus amount obtained after first recycling round, plus amount obtained after second recycling round, etc. An example: If one has 1 kg of a packaging made from primary route material X and can recycle the packaging with 90 % recycling rate, the total amount of uses from the primary materials is 1 kg + 0.9 kg, + 0.81 kg + 0.729 kg etc. It can hence be calculated from the total number of times "n" that the original material, part or energy content is recycled and by the recycling rate "r" of each step


It can hence be calculated from the total number of times "n" that the original material, part or energy content is recycled and by the recycling rate "r" of each step. For the first two recycling loops one obtains "u'" accordingly as: Formula 7 ' r p r p p u u' total amount of uses after first and second recycling loop p primary amount r average recycling rate [0...1), incorporating both collection efficiencies and processing efficiencies


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery With "n" as total number of loops, and simplifying the resulting mathematical series, the total amount of uses after n loops is: Formula 8 r r p r p U n n i i / U total amount of use i recycling loop number n total number of recycling loops In the above example of starting with p = 1 kg and a recycling rate of 95 % (r = 0.95) after indefinite number n of loops one obtains a total amount of use of 20 kg (as in that case U = p/(1-r) ). Second step: Total life cycle inventory of total amount of use The total life cycle inventory of the total amount of use is the sum of the inventories of primary production "P" (up to the level of quality of the waste / end-of-life product), all recycling loops "R", and all final waste management of not recycled fractions and other losses "W"


The repeated recycling processes and the disposal contribute to the total inventory. This total inventory hence includes all processes up to the level of the quality of the primary material, energy carrier or part as obtained also later via recycling, plus all recycling and waste treatment steps. It does not include however any of the processes from the manufacture and use of the products made from the material, energy carrier or part because those processes are not physically related to the production of the later reused/recycled/recovered material, energy carrier, or part232


As prescription one obtains: Formula 9 )) /( ) ( ( * r r r R W P p I n I total LCI of total amount of use of one initial unit of primary material, part or energy carrier P LCI of primary production per unit of material, part, or energy carrier R LCI of effort for reuse/recycling/recovery per unit of material, part, or energy carrier 232 This can best be explained along an example: an aluminium beverage can, as an illustrative example, has as first co-function the function to carry and protect the beverage it contains, its second co-function is the aluminium scrap (i.e. the end-of-life can) it provides as secondary resource for subsequent product systems. To provide the first co-function of delivering the beverage, the can has to be produced, of course


the end-of-life can) it provides as secondary resource for subsequent product systems. To provide the first co-function of delivering the beverage, the can has to be produced, of course. To provide the second cofunction of being a secondary resource in form of scrap it is however sufficient if the aluminium grade the can is made of is produced, while all other steps of transporting the aluminium to the can plant, making the can, etc. are not related / attributable to the provision of the scrap. Hence both co-functions share the production steps until the aluminium grade that is equivalent to that of the scrap is produced. The true co-producing process is hence the one that produces the e.g. metal bar in the quality as it is also available in the e.g. scrap.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery W LCI of final waste management per unit of discarded material, part, or energy carrier Final step: Average inventory per unit and value correction Now the determining physical allocation criterion is to be determined to allocate these cradle-to-gate inventories of the material, energy, or part between the two co-functions. In this case, the criterion is simply mass, as the amount of material, part or energy carrier that is physically required for both co-functions is obviously the same


In this case, the criterion is simply mass, as the amount of material, part or energy carrier that is physically required for both co-functions is obviously the same. From this one can obtain the average inventory "e" per unit of material, part, or energy carrier, dividing the total life cycle inventory of the total amount of use "I" by the total amount of use "U": Formula 10 ) /( ) 1( * ) /( ) ( * * r r p r r r R W P p U I e n n e average LCI per unit of material, part, or energy carrier The above expression for "e" can be further simplified as follows: Formula 11 ) 1( ) ( * ) 1( * n n r r r R r W P e With an indefinite number of loops the expression nr approximates 0 (as r [0...1) and the formula is simplified to yield the final version: Formula 12 r R r W P e * ) 1( * Note that this assumes technical equality between primary produced and reused/recycled/recovered material, part, or energy carrier. If these differ (e.g


If these differ (e.g. as for many recycled polymers), a correction factor is to be introduced. This factor can be understood to correct for not full equivalence of the technical quality of the primary produced material/energy or part from the true co-producing process and the end-of-life product. Especially for complex end-of-life products, this also captures the additional effort for e.g. dismantling towards isolating the different materials or parts. This correction factor should be the market price ratio of secondary/primary material, part, or energy carrier. 14.4.1.3 Market value of waste / end-of-life product is negative (i.e. a waste treatment fee is to be paid) (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) In those cases where the waste / end-of-life product cannot directly be sold, it is not a coproduct but waste. However, there are two types of cases to be differentiated: - In those cases where during the waste treatment no valuable product is produced at all (e.g


However, there are two types of cases to be differentiated: - In those cases where during the waste treatment no valuable product is produced at all (e.g. the waste is directly land-filled, incinerated without energy-recovery, etc.), all waste treatment steps are to be modelled and the inventory is fully to be assigned to the first system that has generated the waste / end-of-life product.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery - In those cases, where during the waste treatment processes a valuable product is produced (e.g. electricity from waste incineration or a secondary good after some additional cleaning and treatment steps, etc.), this secondary good is a co-product of the first system and an allocation is to be applied. This leads to the question, which burden this secondary good is to carry. It is argued that all treatment processes that are necessary until the treated waste / endof-life product is achieving a market value of zero are within the responsibility of the first system (i.e. process steps P1 to including Pn-1 in Figure 33). This is because the waste or end-of-life product is generated by the first system, while a waste can per se not carry any burden of treatment


process steps P1 to including Pn-1 in Figure 33). This is because the waste or end-of-life product is generated by the first system, while a waste can per se not carry any burden of treatment. Furthermore is it considered inappropriate to attribute all preceding waste treatment processes to the eventually produced secondary good233. An allocation of burdens to the secondary goods can plausibly therefore only be done at that process step where a valuable secondary good is produced (Pn). The following procedure shall be applied: Modelling firstly the waste / end-of-life management/treatment processes until the treated waste crosses the “zero market value” border (see Figure 33). Subsequently the two-step allocation procedure is to be applied on this process step


Subsequently the two-step allocation procedure is to be applied on this process step. Figure 33 Allocation of waste / end-of-life products if the management / treatment processes result in any valuable product (secondary good): In addition to the allocation of the good of the true joint process and the secondary good, the inventory of the treatment process step Pn where the waste crosses the zero market value border (MV < O to MV  0) is to be allocated between the two life cycles: The encircled emissions, wastes and products / consumables are to be shared between the pre-treated waste / EoL product (i.e. the first system) and the secondary good (i.e. the second system). See text for details. Note that for the "market price is below zero" case, a double allocation is to be done: Firstly between the co-products of the true joint process (i.e. the primary good that is about equivalent to the secondary good), as always


the primary good that is about equivalent to the secondary good), as always. Secondly, and in addition, between the pretreated waste / end-of-life product that enters the process Pn that stands at the border between the first and second life cycle and the secondary good that leaves it (see Figure 33). For both these two allocations, the same two-step procedure of chapter 7.9.3 is applied: 1st criterion of determining physical causality: if such exists during the process step when a valuable product (secondary good) is obtained, the corresponding inventory values are allocated between the first life cycle and the secondary good. 233 An example: if the waste is a highly toxic waste that needs special transport, storage and treatment in a waste incineration facility and finally a little amount of electricity is produced, this cannot justify assigning the high environmental impact of the waste treatment incl. depositing of remaining waste and ashes to the electricity


depositing of remaining waste and ashes to the electricity. For accounting different versions of products over time, this approach would e.g. not capture improvements in the quantity or quality of wastes and end-of-life products. 2nd (product) system 1st (product) system Secondary good MV Waste / EoL product (MV < 0) Pre-treated waste / EoL product (MV < 0) Emissions Wastes ... ... Products Wastes Products Emissions ... Use phase P1...n-1 Pn


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery 2nd criterion of market value: the remaining inventory exclusively of the process step that produces a valuable product (secondary good) is allocated with the market value criterion between the secondary good(s), i.e. the second life cycle, and the (potentially pre-treated) waste / end-of-life product that enters this process step, i.e. the first life cycle. Note finally that the market value of the pre-treated waste / end-of-life product before it enters the process step that finally produces a valuable secondary good, is below zero and that hence the absolute value of its (negative) market price234 shall be used when allocating between the first and second life cycle. The rest of the allocation calculation is the same. Note: the Provisions of this annex are found in the main text, in chapter 7.9.3


The rest of the allocation calculation is the same. Note: the Provisions of this annex are found in the main text, in chapter 7.9.3. 14.5 Recycling in consequential modelling (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) 14.5.1 Introduction and overview As explained earlier, reuse/recycling/recovery in consequential modelling is methodologically equivalent to other situations of multifunctionality. It has some special aspects that are logically derived from the same modelling approach while they lead not always to immediately intuitive solutions. They are explained in this chapter. 14.5.2 Recyclability substitution approach (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) The recyclability substitution approach (also called "end-of-life recycling" or "recycling potential" approach235) follows the logic of consequential modelling236 and is its archetypal approach for solving multifunctionality. This mechanism stimulates high recyclability in both quantity and quality


This mechanism stimulates high recyclability in both quantity and quality. Note that the content of recycled material in the product itself is not directly considered in the final inventory, as that amount is corrected by the product's recyclability. In the further text, details are provided how and why this approach (combined with a correction for reduced technical properties/functionality) is also appropriate in case the recycled content needs to be stimulated for the material that is analysed. The recyclability substitution approach is described in the following Box and illustrated in Figure 34. 234 If the market value / gate fee of the pre-treated waste is e.g. „-1 US$“, the market value used for allocation would be „1 US$“. (One can interpret this also as an allocation between the secondary good and the waste treatment service that is here priced at "1US$")


(One can interpret this also as an allocation between the secondary good and the waste treatment service that is here priced at "1US$"). 235 The term "recycling potential" is not well capturing - at least for short-lived products - that the actually achieved recycling rate is used. The term "end-of-life recycling" is only covering end-of-life products, but no production waste and has no methodological reference in its name. Hence, a different term is used here, combining the used criteria "recyclability" with the applied method "substitution". 236 See the footnote 24 on the question whether this approach and substitution in general are an attributional or a consequential approach. In fact, it is argued to be an approach both to model "additional consequences" (as done in Situation A and B) and "existing consequences" (as done in Situation C1); the latter could also be termed "interactional".


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Terms and concepts: Recyclability substitution approach In the recyclability substitution approach, the avoided inventory of primary production of a good is credited to the end-of-life product or waste according to the degree that it is recyclable. Only the amount of good that cannot be quantitatively obtained back from the secondary good (i.e. losses due to incomplete collection, losses during recycling, etc.) is modelled as primary production. The recycling efforts, deposition of any finally remaining waste etc. and the related impacts are part of the first life cycle. Note that this is analogous to substitute the mix of the most cost-competitive or least cost-competitive processes/systems


and the related impacts are part of the first life cycle. Note that this is analogous to substitute the mix of the most cost-competitive or least cost-competitive processes/systems. An example for "closed loop" and "open loop - same primary route" recycling (see Figure 30 and Figure 31, respectively): A product Y, made from only one material X (to make the example clearer) is produced from 2 kg primary material and 2 kg secondary material (i.e. recycled content = 50 %); see top graphic in Figure 34. The 3.5 kg that are recycled result in 3 kg secondary good of the same quality as the one produced via the primary route (recyclability by mass = 75 %). The surplus of 1 kg secondary good, that is not required for the product's production, is substituted (see the curved arrow and the "S" in the graphics) by 1 kg primary production of material X ("-1 kg")


This results in an effective inventory for the analysed system of 2 kg - 1 kg = 1 kg of the primary-produced material X, plus its assembly and use stage, plus the “recycling-processes-only” inventory of 3.5 kg of the recycled end-oflife product, plus waste disposal processes for each 0.5 kg of the directly deposited end-oflife product and 0.5 kg of waste generated during recycling. Note that it does not matter whether the 2 kg used secondary material stem from the recycling of this product or any other product made of that material. (In case the quality of the secondary material would be lower than the quality of the primary material, this would be considered by crediting a lower amount or by market-value correction). If in the above example, the recyclability would be lower than the recycled content, e.g


If in the above example, the recyclability would be lower than the recycled content, e.g. resulting in only 1 kg secondary material (second graphic in Figure 34), the lacking 1 kg of material would be added by primary produced material X ("1 kg"), to complete the required 4 kg. Applying the same approach, but this time for another product, assuming that the secondary material X would normally not be used but disposed off (see third graphic in Figure 34): if 3 kg of the secondary material X are produced but only 2 kg are used in the production of the product, 1 kg needs to be disposed off; this is to be modelled instead of crediting avoided primary production ("1 kg" to disposal; see lower left process box). If however the analysed product would using more secondary material X than it produces (bottom graphic in Figure 34), this means that the here additionally required 1 kg of secondary X has to come from somewhere else


As any additionally produced amount secondary X is disposed off, this additional demand diverts 1 kg of secondary material X from landfill, i.e. the product gets a credit of 1 kg avoided disposal ("-1 kg" avoided disposal; see lower left process box). In summary, this approach is rewarding a high recyclability, especially of valuable resources/goods and/or recycling to higher value secondary goods. Recycled content is rewarded when otherwise unused/landfilled secondary resources are used. Note that the routes of primary production and of the substituted primary production do not need to be identical, as e.g. a specific route may be used for the purchased material, while the credit would be given for the mix of the most cost-competitive routes (under full consequential modelling; but see simplifications for Situation A, B, and C1)


Lower quality of the secondary good is considered by substituting accordingly less primary production or applying value correction (details see chapter 14.5.3.3).


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Note that the recyclability substitution approach applies fully analogously to production waste and to other forms than recycling such as energy recovery, parts reuse, etc. An example for open-loop recycling, with the example of "further use" of a product: If I produce a metal-table of 4 kg metal X and after some years, I foresee a further use of the table (e.g. high class restaurant that is selling their tables after 5 years for further use elsewhere). The alternative route for the buyer of these tables is the primary production of such a table. Given the 5 years reduced average lifetime (at a total technical lifetime of e.g. 20 years), we would give a credit237 of 15/20 = 75 % of the inventory of the newly produced table. These 75 % of the remaining lifetime is the functional equivalent the product has


20 years), we would give a credit237 of 15/20 = 75 % of the inventory of the newly produced table. These 75 % of the remaining lifetime is the functional equivalent the product has. In addition, after its useful life the table can still be recycled, achieving an e.g. 87.5 % recyclability rate, i.e. 87.5 % (i.e. 3.5 kg) primary metal production would be credited to the combined life cycles of the first and second use of the table. If the original table was produced with 2 kg primary metal X and 2 kg secondary metal X, we have a surplus of 3.5 kg - 2 kg = 1.5 kg secondary metal X, for which the system gets the respective credit of avoided primary production. As the recycled metal and the credits are part of the production of the table, in the end the first use of the tables carries 25 % of the inventory and the further (i.e. second) use 75 %, plus each of them any specific activities during their use such as cleaning etc. Note that if instead of the functional equivalent (i.e


second) use 75 %, plus each of them any specific activities during their use such as cleaning etc. Note that if instead of the functional equivalent (i.e. table years of use) the market value correction would be used, it can be assumed that the first use of te table would carry a higher share of the overall inventory, as a 5 year old table would probably be sold for less than 75 % of its original price. This illustrates that it is important to aim at depicting the actually replaced quantity of the function, instead of using the value correction; any lack of accuracy from the value correction would need to be considered in the interpretation. Note also that this is also an example of joint production, of the two uses of the table. The example also illustrates that for cases of "further use" it is necessary to consider the full cycle, here up to recycling back to the originally produced material, along all the uses that the original material may have (as far as quantitatively relevant)


The recyclability substitution approach then simply calculates the inventory per functional unit (here: 20 years table use) and that the different uses of the table (here: 5 years restaurant, 15 years other uses) carry the same inventory per unit of function (here: per year of use). What if the end-of-life of the table after its second use would result in very different use (e.g. the metal would be powdered and used as some polymer filler), i.e. there is no link back to the original table production: the table would get a credit of avoided production of the superseded alternative filler. The table production would be modelled entirely from primary produced metal as the system is an open-loop system, i.e. does not return secondary metal. The two uses of the table share the inventory in the same ratio as above, per functional unit, here per year of useful life. 237 Applicable in a growing, stable or slightly declining market.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Extraction Material production Part production & Assembly Use Disposal Recycling 2kg 4kg 0.5kg 4kg 2kg 3kg (recyclability = 75%) 2kg 4kg 3.5kg 0.5kg disposal processes for 0.5kg+0.5kg recycling processes for 3.5kg primary production for 2kg −(avoided) primary production for 1kg = primary production for 1kg S Extraction Material production -1kg -1kg Extraction Material production -1kg -1kg Extraction Material production Part production & Assembly Use Disposal Recycling 2kg 4kg 2.5kg 4kg 1kg 1kg (recyclability = 25%) 2kg 4kg 1.5kg 0.5kg disposal processes for 2.5kg+0.5kg recycling processes for 1.5kg primary production for 2kg + 1kg = 3kg S Extraction Material production 1kg 1kg Extraction Material production 1kg 1kg 1kg Extraction Material production Part production & Assembly Use Disposal Recycling 2kg 4kg 0.5kg 4kg 2kg 3kg (recyclability


Material production 1kg 1kg Extraction Material production 1kg 1kg 1kg Extraction Material production Part production & Assembly Use Disposal Recycling 2kg 4kg 0.5kg 4kg 2kg 3kg (recyclability = 75%) 2kg 4kg 3.5kg 0.5kg disposal processes for 0.5kg+0.5kg recycling processes for 3.5kg Disposal (secondary material) 1kg primary production for 2kg disposal processes for 1kg S Extraction Material production Part production & Assembly Use Disposal Recycling 2kg 4kg 2.5kg 4kg 1kg (recyclability = 25%) 2kg 4kg 1.5kg 0.5kg disposal processes for 2.5kg+0.5kg recycling processes for 1.5kg Disposal (secondary material) -1kg primary production for 2kg avoided disposal processes for 1kg S 1kg 1kg Figure 34 Recyclability substitution approach


Explanations see "Terms and concepts" box and text. Note that this applies analogously to reuse and recovery processes.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery 14.5.3 Detailed aspects of using the recyclability substitution approach of consequential modelling (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) 14.5.3.1 Introduction (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) The recyclability substitution approach is especially suitable for “closed loop” and “open loop – same primary route” cases and where the secondary good enters the same system somewhere else in the background system (e.g. electricity from waste incineration). However, also if the secondary good is of a different kind as the primary good (i.e. in open loop - different primary route situations), analogous results are achieved by crediting the respectively superseded mix of other processes / systems


in open loop - different primary route situations), analogous results are achieved by crediting the respectively superseded mix of other processes / systems. For closed loop cases, this approach can also be interpreted / understood as a (product) system wide, average internal recycling loop, with any surplus of secondary goods provided (compared to the recycled content of the recycled end-of-life product or waste) resulting in additional credits for avoided primary production and any reduced provision of secondary goods resulting in additionally modelled primary production. It also applies if the secondary good has a lower quality than its primary route delivers (as can be the case e.g. for recycling of post-consumer plastic waste). In that case, the change in functional equivalence between the secondary good and the superseded product is considered


for recycling of post-consumer plastic waste). In that case, the change in functional equivalence between the secondary good and the superseded product is considered. Four aspects need attention in this context when applying the recyclability substitution approach:  The way how the recyclability is defined/measured,  changes in the inherent properties of the secondary good,  identifying the superseded process(es), and  time aspects in “delayed” recycling of long-living products. Note that in analogy to delayed Climate change relevant emissions from other processes (see chapter 7.4.3.7.3), also delayed Climate change relevant emissions and credited future avoided burdens from recyclingshould be considered in the inventory


However, in calculating the results and interpretation, the storage and delayed emissions are only considered if a discounting of climate change / radiative forcing is explicitly foreseen as part of the goal definition of the study; per default this is not considered, since the LCA approach per default is not discounting impacts over time. These issues are addressed in the following subchapters: 14.5.3.2 Determining recyclability (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) Under recyclability in the sense as required for use in the recyclability substitution approach, the term is to integrate all losses that occur for whatever reason. This covers all process from the point when the waste is generated or the end-of-life product is reaching the end of its useful life to the point of the produced secondary good. This includes e.g. loss due to incomplete collection, sorting, recovery, during recycling processing, rejection, etc


This includes e.g. loss due to incomplete collection, sorting, recovery, during recycling processing, rejection, etc. In short, the recyclability is the % of the primary good's amount in the waste or end-of-life product that can be found in the secondary good(s).


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Both average numbers for a material can be of interest and product-specific recyclabilities (e.g. 85 % average recyclability of material X in Europe, or 70 % specific recyclability of material X from product Y); this depends on the study. Note that for different materials, parts etc. that are reused/recycled/recovered from complex products, these calculations need to be done separately for each secondary material, part, etc. (e.g. copper and PVC from cable recycling). For practical reasons and for long-living products the recyclability should per convention be the currently achieved recyclability for this product (or for new/projected products of comparable products in the same market). This is unless the study would explicitly look at the effect of different recyclability scenarios e.g. in design-for-recycling studies


This is unless the study would explicitly look at the effect of different recyclability scenarios e.g. in design-for-recycling studies. 14.5.3.3 Changes of inherent technical properties of the secondary good (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3.2) The technical properties of a material or part can be unfavourably changed in the refurbishing, recycling or recovery process (e.g. shortening of fibres in paper recycling, greyish colour and less good processing properties of recycled polymers due to limited sorting specificity and remaining content of additives, fillers etc., shortened lifetime of a reused mechanical motor part, etc.). This “down-cycling” can mean that the secondary good cannot replace the primary produced material or part, or only in certain applications. In addition or alternatively this can mean that the secondary good can replace it only after additional measures have been performed, and/or to a limited degree, or for a limited duration (e.g


In addition or alternatively this can mean that the secondary good can replace it only after additional measures have been performed, and/or to a limited degree, or for a limited duration (e.g. due to a reduced lifetime of a reused part). For those e.g. materials that degrade during use and recycling, this puts a limit to the number of cycles that they can go through, also independently from any quantitative losses that occur. There is a range of specific consequences and corresponding solutions to address this “down-cycling”, that need a closer view: In some cases, the secondary good can only replace the primary produced material or part in some of the applications, where the requirements to the changed property are not too demanding. In other cases, a higher amount of the recycled material is needed than of the virgin material, in order to provide the same functionality (e.g. stiffness of a polymer part)238


In other cases, a higher amount of the recycled material is needed than of the virgin material, in order to provide the same functionality (e.g. stiffness of a polymer part)238. In again other cases, the down-cycled secondary material is to be mixed with primary material or higher quality secondary material to meet the minimum technical specifications. On the other hand, the effect of downcycling may be substantially counteracted by special technologies: these may be able e.g. remove a too high amount of tramp elements from steel. Or e.g. subsequent purification steps are applied to recovered solvents. In summary: The changed properties of the potentially down-cycled secondary good and the consequences in its use must be considered when modelling the substitution


In summary: The changed properties of the potentially down-cycled secondary good and the consequences in its use must be considered when modelling the substitution. This is done by two mechanisms: if the specific use or uses of the secondary good are known, the actually replaced amounts of the superseded process(es) / system(s) are 238 Note however that: this is a different issue that is not to be explicitly considered here as it is implicitly already covered via a lower market price.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery modelled. If the uses or amounts are not known, “value correction”239 is applied, i.e. by using the market-price ratio of the secondary good to the superseded primary produced good, crediting an accordingly reduced amount of the primary material inventory. Two examples are given to illustrate this value correction, one for "closed loop" or “open loop – same primary route” recycling and one for "open -loop - different primary route": If e.g. for a polymer-based product of 0.2 kg weight, the recycled polymer granulate may have a market price of e.g. 0.9 US$ / kg. The primary material granulate that is replaced in the same (or different) product may cost 1.2 US$. In that case only 0.9/1.2 = 0.75 shares (i.e. 75 %) of the 0.2 kg, i.e. 0.15 kg, primary polymer would be substituted (“credited”)


In that case only 0.9/1.2 = 0.75 shares (i.e. 75 %) of the 0.2 kg, i.e. 0.15 kg, primary polymer would be substituted (“credited”). An example of "open loop - different primary route" recycling, involving energy-recovery: For another polymer-based product of 0.2 kg weight, the recycled polymer might due to e.g. material-degrading after long-time use or due to soiling etc. only be used for energy recovery. The secondary good would in that case be the e.g. 0.28 kWh240 electricity generated from the incinerated plastic waste that is fed into the grid. This electricity is technically equivalent but also be assumed to have the same market price as the average large producer electricity price of e.g. 0.04 Euro per kWh. In consequence, the full241 0.28 kWh primary produced electricity would be substituted (“credited”)


0.04 Euro per kWh. In consequence, the full241 0.28 kWh primary produced electricity would be substituted (“credited”). Under full consequential modelling, the superseded electricity would be the mix of the most 242cost-competitive technologies of the electricity market / country where the recycling takes place (but see the simplifications for Situation A, B, and C1). The next text-sections will show that this approach is reasonable also for very different reasons: 14.5.3.4 Identifying superseded processes in line with market consequences to consider (Refers to aspect of ISO 14044:2006 chapter 4.3.4.3) It is often argued, that the life cycle model should give the correct incentives for more and better recycling, if there is a high demand for this secondary good or for higher quality. At the same time it should give an incentive for more use of the secondary good, if there is little demand for it


At the same time it should give an incentive for more use of the secondary good, if there is little demand for it. For meeting these requirements, two different perspectives can be taken to identify the superseded process(es): firstly the consequential approach of identifying the superseded processes / systems. Secondly the perspective looking at how to steer the waste 239 Another and more specific approach discussed is to use the changes in the relevant specific technical properties as corrector. While this would allow using a correction-factor that closer relates to the technical properties, it has a number of shortcomings: 1) It involves subjective choices on which technical property to use for correction. This lowers the reproducibility, even more so as often several properties are affected that only jointly define the technical usability/value of a secondary good. These properties cannot simply be added up, as they are measured in all kinds of different units


These properties cannot simply be added up, as they are measured in all kinds of different units. Also, some properties may be qualitative (e.g. mixed and dark colours of secondary goods). 2) The technical properties do not reflect the important question, whether there is a real market for the secondary good or not, as e.g. perception („waste image“, „green image“) plays an important role as well. 3) The necessary technical information is typically more difficult to collect or measure that are the market prices. 240 The number is illustrative and approximate only: 0.2 kg e.g. PP has roughly 10 MJ lower calorific value energy content. At 10% conversion efficiency of the waste incineration plant to electricity (considering the internal consumption for off-gas cleaning etc.) 1 MJ electricity, i.e. 1 [MJ] / 3.6 [kWh/MJ] = ca. 0.28 kWh remain


1 [MJ] / 3.6 [kWh/MJ] = ca. 0.28 kWh remain. 241 While 100% of the produced electricity is credited, the absolute environmental benefit that is credited is clearly lower than crediting the use of replacing the 0.15 kg primary PP of the preceding example. 242 "Most" cost-competitive if the market is "growing, stable, or slightly declining", as assumed in case of this electricity market.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery / end-of-life product situation towards an overall improvement, i.e. reduction of impacts. The following paragraphs look at the same question from these two perspectives: Consequential modelling perspective In consequential modelling, considering the two cases of "growing, stable, or slightly declining" markets and of "strongly declining" markets, and deriving the most likely superseded processes, the following would be modelled:  Additional supply of the secondary good, as surplus from recycling (i.e. more secondary good generated than used in the product's production): - For "growing, stable, or slightly declining" markets, the additionally available amount of the secondary good would supersede the mix of the most cost-competitive primary production process(es) of the same material, energy, or part


- In "strongly declining" markets, the additionally available secondary good could be argued to not be used at all. However, the way the recyclability is defined here, i.e. capturing the actual availability and use of the secondary good in the market, it is de facto used and is to be credited as well. It will supersede in this case the mix of the least cost-competitive processes / systems. If the secondary good is at least partly un-used (i.e. deposited)243, any additional supply would directly go to waste depositing, as the market is already saturated/over-supplied. Accordingly, no credit is given, but waste depositing is modelled


deposited)243, any additional supply would directly go to waste depositing, as the market is already saturated/over-supplied. Accordingly, no credit is given, but waste depositing is modelled.  Additional demand for the secondary good: An additional demand for the secondary good occurs, if the amount of secondary good that is generated by recycling is smaller than the amount that is used in the product's production: - In "growing, stable, or slightly declining" markets again the most cost-competitive processes / systems would be affected, in this case the production of the lacking amount is modelled as additional primary production inventory. If this additional demand relates to an at least partly un-used (i.e. deposited) secondary good, the avoided waste treatment of the otherwise not used secondary good is credited. - Finally, in "strongly declining" markets, the additionally demanded secondary good would supersede again the mix of the least cost-competitive processes / systems


- Finally, in "strongly declining" markets, the additionally demanded secondary good would supersede again the mix of the least cost-competitive processes / systems. If the secondary good is at least partly un-used (i.e. deposited), any additional demand would avoid the waste deposition of the same secondary good that is produced from other waste or end-of-life products. Accordingly, a credit for avoided waste depositing is given. The specifically superseded amount of primary good or the relative market value of the secondary good vs. the replaced good is used to reflect the reduced technical properties of the secondary good. If this information is lacking, market-value correction is done. 243 This is indicated by a market value of below zero, while still it is used in some application. Note that the value is below zero and not "zero or below", as the waste depositing has a cost (i.e. a gate fee is to be paid)


Note that the value is below zero and not "zero or below", as the waste depositing has a cost (i.e. a gate fee is to be paid). That means that it is not automatically clear from the market price alone whether a secondary good is at least partly deposited. This is exactly then the case if the negative market value equals the waste fee. These fees differ considerably among countries globally and also for the type of waste to be deposited; they are roughly in the range of -0.005 US$ and -0.5 US$ per kg.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery Perspective of creating Incentives for increased recyclability vs. increased use of secondary goods In markets that are growing or where for other reasons (e.g. “green image”) the demand for a secondary good is higher than the amount that is available via recycling/reuse/recovery (e.g. in most but not all current material markets), the main necessity is obviously to increase the recycling rate (i.e. recyclability) and not the demand for recycled materials (i.e. recycled content). A comparatively high market price of the secondary good compared to the price of the same primary good means at least one of the following: - the market is growing AND the recycled material is of sufficient / high quality and/or - there is demand for the secondary good for other reasons (e.g


positive “green” perception) In consequence, mainly the quantitative extent of reuse/recycling/recovery needs to be promoted, i.e. the recyclability. This is what the approach “recyclability substitution” does. A comparatively low price of the secondary good (compared to the one of the primary produced good) indicates at least one of the following: - there is a high recycling rate for some reason that provides an excess of the secondary good, and/or - the achieved technical quality of the secondary good is low (in view of the required minimum quality for most applications; this is typical for down-cycling in open loop), and/or - there is a limited demand for the secondary good for other reasons (e.g. “wasteimage” perception, hygiene legislation, etc.). If the amount that is available via reuse/recycling/recovery is higher then the demand, and the market value is accordingly below zero, the main necessity is to increase the demand for the secondary good (i.e


recycled content) and/or its technical quality (i.e. high-quality recyclability), but not the simple recycling rate (i.e. general recyclability). That situation seems to call for either using the recycled content approach, or for only considering high-value recyclability, or overcoming the obstacles/constraints of e.g. hygiene legislation. This however would need a deeper investigation of identifying the underlying causes while a generally applicable, reproducible calculation rule is required here that still provides the right incentives. Is the recyclability substitution providing this solution?: The recyclability substitution considers the reduced technical properties, i.e. how much of which alternative primary good the secondary good is able to replace. Or it considers this via value correction. In both cases, for producing low quality / low value or even value-less secondary goods, a lower credit is given


Or it considers this via value correction. In both cases, for producing low quality / low value or even value-less secondary goods, a lower credit is given. The value-corrected credit reflects hence both the amount and quality of the secondary good, stimulating higher quality recycling or other measures that effectively overcome other existing obstacles to use the secondary goods (e.g. overcoming waste image, changing legislation, etc.). If the additional supply of secondary good is just ending in a waste deposit, no credit is given, but waste depositing is modelled. If the analysed system uses otherwise deposited secondary goods, the recyclability substitution approach gives a clear incentive to do so, as avoided waste depositing is credited - the more is used as recycled content and the more problematic the waste's deposit behaviour is, the more credit is given. In such cases, a higher recycled content is rewarded


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery and stimulated. This stimulation is proportionally stronger, the lower technical quality / value the secondary good has. Conclusion The recyclability substitution approach with value correction and considering the supply/demand of otherwise deposited secondary goods yields the right incentives for both stimulating quantity and quality of recyclability and use of secondary goods, as required in the respective situation


14.5.3.5 Time aspects in “delayed” recycling of long-living products (Refers to aspect of ISO 14044:2006 chapters 4.3.4.3, 4.2.3.5, 4.2.3.6.2 and 4.3.2.1) If carbon storage and delayed emissions are considered in an LCA study, the following applies: In line of the 100 years time-horizon of inventory data collection and Climate change impact modelling, the question arises, how to account for the delayed/future benefits of providing recyclable long-living products to future generations. For the question of biogenic and fossil delayed emissions of greenhouse gases, the same question was answered by using a special flow that keeps the information of the delay of up to 100 years in the inventory. Using the same approach, future recycling is to be modelled by using a correction flow for greenhouse gases related to recycling operations and equally for the credits of future reuse/recycling/recovery. This is done by using the same correction flows, so that the full information is kept


This is done by using the same correction flows, so that the full information is kept. However, as LCA in general has an infinite time-horizon, by default this correction flows are not considered when calculating the results. If radiative forcing is explicitly meant to be discounted to zero over 100 years from the time of the study, this is to be explicit part of the goal definition. This means that only in that case the avoided future emissions of CO2, CH4 and N2O for avoided primary production of e.g. copper from cables, calculated using the recyclability substitution approach, would be scaled down for a product with a life-time of 10 years (e.g. a car) by 10 % (i.e. 10 years / 100 years). Note: the Provisions of this annex are found in the main text, in chapter 7.2.4.6; but observe the specific simplified provisions made for Situation A, B, and C1 in chapters 6.5.4.2 and 6.5.4.3.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 14 Annex C: Modelling reuse, recycling, and energy recovery


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation 15 Annex D: Avoiding misleading goal and scope definition and results interpretation (No corresponding ISO chapter but referring to a number of chapters) 15.1 Introduction and overview (No corresponding ISO chapter but referring to a number of chapters) Sometimes, elements of the goal and scope definition are, possibly inadvertently, performed in a way that leads to misleading results. Or the results of an LCA are interpreted in a way that is not in accordance with the goal of the study or the way the analysis was scoped, and this again leads to misleading conclusions244. This appendix identifies types of errors that are made in the goal and scope definition and in the interpretation of an LCA study that can lead to misleading results and conclusions


This appendix identifies types of errors that are made in the goal and scope definition and in the interpretation of an LCA study that can lead to misleading results and conclusions. It hence guides towards non-misleading goal and scope definition and results interpretation. 15.2 Misleading goal definition and scoping (No corresponding ISO chapter but referring to a number of chapters) The goal definition defines the decision-context of the study, identifies the intended applications of the results, and names the targeted audiences. The scoping of the study is done in accordance with the goal definition, and the interpretation must also respect the goal definition. The goal definition itself might be not misleading


The scoping of the study is done in accordance with the goal definition, and the interpretation must also respect the goal definition. The goal definition itself might be not misleading. It can however state something else than what is truly the goal of the LCA but if the scoping, the LCI and LCIA work is done in accordance with the stated goal, the misleading only occurs when the results of the LCA are interpreted according to the true goal rather than the defined goal. This is an error that occurs during the interpretation and is discussed there. In other cases also the interpretation of the results may be correct, but the results that may build on very specific goals are condensed in a way that the leads the reader to misunderstand and misinterpret or generalise the factually very limited recommendations. In this sense, also the definition of goals needs guidance to avoid it can be the basis for misleading results interpretation


In this sense, also the definition of goals needs guidance to avoid it can be the basis for misleading results interpretation. The goal definition must hence be very clear on: - the comparative character of the LCA study (e.g. “Comparison of the environmental impacts associated with fuel-type A and fuel-type B for use in private cars in Country X”) and if assertions about environmental superiority or equality are made and these are foreseen to be published, - the reasons to carry out the study, including the decision-context (e.g. “Support governmental decisions on the introduction of new fuel-types for private cars in Country X”), - who commissioned the study (e.g. “The National Ministry for Transportation in Country X”), and 244 After the goal definition and scoping, another main source of misleading results lays in the inventory and impact assessment phases: this is when the goal and scope settings are implemented in a deviating way


This is however not an issue of misleading goal and scope definition and results interpretation, but of incorrect LCI and LCIA work in general and not further discussed here.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation - the target audience of the study, especially whether these have technical knowledge or LCA knowledge Furthermore are goals to be avoided that - analyse highly specific and uncommon e.g. product use case scenarios, comparing a product A exclusively with an outdated, highly inefficient and polluting alternative product B with the purpose to later demonstrate and communicate to the public the “environmental superiority of product A”. This is misleading if products C, D, etc. would be in the market, having a better environmental performance than A. Several aspects of the scope definition present a risk of errors that can lead to misleading results


would be in the market, having a better environmental performance than A. Several aspects of the scope definition present a risk of errors that can lead to misleading results. Important examples are given in the following sections 15.2.1 Functional unit (No corresponding ISO chapter but referring to a number of chapters) Failing to base comparisons on a valid functional unit: In the cases where the LCA is intended for comparison of two or more products or systems, the functional unit must give an unambiguous definition of the service or function that the compared products must provide. Based on this definition the reference flows of the products can be determined. When the functional unit does not reflect the service provided or the reference flows are not based on a functional unit, seriously misleading results may occur. Examples are:  The chassis of a television set can be made from plastic type A, from metal M or from bio-based material B


Examples are:  The chassis of a television set can be made from plastic type A, from metal M or from bio-based material B. In order to decide which of the three solutions has the lowest environmental impacts, the material impact profiles are compared for one kg of each material. This is a misleading choice of reference flow since the weight of material required to construct the chassis differs between the three materials. The correct reference flows should be derived from the functional unit (in this case one television set) and would for each material reflect the quantity applied in producing the chassis of same technical quality (e.g. mechanic stability, durability, etc.). It is rarely appropriate to compare materials on an equal weight basis.  A study is intended to guide the choice between refillable bottles of material A and oneway beverage cartons of material B for distribution of milk to households. An LCA is performed for one bottle and one beverage carton


An LCA is performed for one bottle and one beverage carton. This is a misleading choice of reference flow since it ignores the fact that on average the refillable bottle is returned and reused to give a total of e.g. 25 use situations while the beverage carton is used only once. At the same time would this ignore among others the need for return transport, cleaning, etc. of the bottles and the benefit of e.g. recycling and/or energyrecovery of both products after their use. Again, the relevant reference flows should be derived from a correct functional unit, which might be ”Packaging 1000 litres of fresh milk in 1 l containers that may serve for distribution and storage of the milk in the chain from dairy to the private household”. With this functional unit the relevant basis of comparison would be reference flows of e.g. 1000 beverage cartons and 40 bottles245.  In a comparison of two farming methods, the impacts from cultivating one hectare with wheat are compared


1000 beverage cartons and 40 bottles245.  In a comparison of two farming methods, the impacts from cultivating one hectare with wheat are compared. This is a misleading choice of functional unit if the results are 245 Note that in addition other functional aspects would need to be considered such as comfort, shelf-life, protection from light or from smell of the fridge, etc.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation used to support comparison of the products in which the wheat is applied: it ignores e.g. the fact that the yields will often differ between different farming methods. Quality differences of the wheat may additionally need to be considered. The correct functional unit should specify the amount of products to be compared, not the area cropped


Quality differences of the wheat may additionally need to be considered. The correct functional unit should specify the amount of products to be compared, not the area cropped. 15.2.2 Modelling principle (No corresponding ISO chapter but referring to a number of chapters) Failing to choose the proper LCI modelling principle and associated approaches The choice of modelling principle - attributional or consequential - decides whether the technologies to be covered by the collected unit process data in the inventory analysis should reflect the average technology for a given region and time-period or rather the marginal technology that is increased or decreased in use as consequence of the studied decision. The decision-context of the goal of the LCA determines the appropriate LCI modelling principle and method approach to be applied. Considering other issues such as reproducibility and robustness the practical guidance of this guidance document was derived


Considering other issues such as reproducibility and robustness the practical guidance of this guidance document was derived. The difference between the marginal and the average can be large for some technologies. In the case of electricity generation, the marginal technology can be coal-fired power or windpower, while the average technology will typically look very different. For products or systems that use much electricity, the single choice of electricity technology (mix) will often be decisive for the overall results and the wrong choice of modelling principle will then give misleading results. The same issue applies to all kinds of processes and is hence one of the most outstanding methodological choices in LCA


The same issue applies to all kinds of processes and is hence one of the most outstanding methodological choices in LCA. 15.2.3 Drawing of system boundaries (No corresponding ISO chapter but referring to a number of chapters) Leaving out activities or whole life cycle stages that are environmentally relevant The iterative procedure applied in LCA is intended to assure that the important processes and activities are included in the inventory analysis. That means that the system boundaries are drawn so only things of minor importance are left out, and that the data quality is sufficiently strong for the most important processes to ensure robust results for the intended applications. Misleading results may occur when system boundaries are drawn in a way that important processes are excluded e.g. due to:  Use of too weak or irrelevant cut-off criteria (e.g


Misleading results may occur when system boundaries are drawn in a way that important processes are excluded e.g. due to:  Use of too weak or irrelevant cut-off criteria (e.g. limited to mass and energy), when the chosen cut-off criteria are not in accordance with the requirements given by the intended application. Or when cut-off criteria are set on single elementary flows without consideration of their individual environmental impacts. The latter is particularly a problem for the chemical-related impact categories addressing human toxicity and ecotoxicity, where elementary flows can have characterisation factors that differ by many orders of magnitude.  Lack of proper screening and iterative approach causing the practitioner to focus on the wrong processes in the data collection of the inventory and miss the most important processes.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation Systematic exclusion of activities that play a quantitative role without checking whether this is justified by their insignificant contribution to the overall impacts – e.g. a priori decide to exclude: - the production of capital goods - services ( e.g. “retailing” when comparing frozen/non-frozen food, “maintenance” when comparing sensitive equipment, “transportation” or “storage” of products - consumption of auxiliary materials (e.g. lubricants, detergents, etc.) - waste treatment (e.g. wrongly considering them as appropriate inventory flows or assuming their irrelevance).  Systematic exclusion of complete life cycle stages due to missing insight of their relevance for the compared products (see e.g. the example on beverage boxes vs. bottles where reuse and end-of-life where wrongly ignored to be of relevance)


the example on beverage boxes vs. bottles where reuse and end-of-life where wrongly ignored to be of relevance). An example: In a comparison study of reusable cotton diapers and one-use diapers it would thus be misleading if one or more of the following elements were omitted from the system scope: - End-of-life of reusable diapers (also reusable products must be disposed of) - Retail and shopping of many single-use diapers vs. one reusable diaper - Auxiliary materials, e.g. ° Detergent for washing of reusable diapers ° Packaging for single-use diapers ° Special pants for reusable diapers, worn to ensure comfort ° ..


one reusable diaper - Auxiliary materials, e.g. ° Detergent for washing of reusable diapers ° Packaging for single-use diapers ° Special pants for reusable diapers, worn to ensure comfort ° ... 15.2.4 Choice of LCIA impact categories, LCIA methods, normalisation and weighting sets (No corresponding ISO chapter but referring to a number of chapters) Limitations in coverage of environmental impacts The selection of impact categories must be consistent with the goal of the study and the intended applications of the results, and it must be comprehensive in the sense that it covers all the main environmental issues related to the system. If the goal definition does not specifically limit the scope of impacts to be covered (e.g. by defining the study as a carbon footprint study or an analysis of the energy flows in the life cycle), serious misleading may occur by omitting some of the impacts that the system has


by defining the study as a carbon footprint study or an analysis of the energy flows in the life cycle), serious misleading may occur by omitting some of the impacts that the system has. This is in particular when two technologies that differ in their pattern of environmental impacts are being compared. Take as an example high pressure cleaners A and B that both use electricity and water in the use stage. Cleaner B also applies detergents in the water stream and thereby provides the cleaning function specified in the functional unit with smaller use of water and energy. The use of detergents also leads to impacts in their production and use stage. An LCA that only focuses on the water and energy use will be in the favour of cleaner B but the results can be misleading if the detergent-related impacts are important.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation Selection of specific LCIA methods and normalisation and weighting sets The LCIA methods (and any normalisation or weighting factors) are to be identified in the scope definition and this decision is to be documented. Misleading results may intentionally be created by changing the choice of LCIA methods and normalisation or weighting factors after seeing the results of the impact assessment. If sub-sequent changes would be made, LCIA factors could be chosen that give the most positive results for the commissioner‟s own product. 15.2.5 Representativeness of data (No corresponding ISO chapter but referring to a number of chapters) Representativeness is the ability of the inventory data to describe the emissions and environmental impacts of the system


It depends on how well the inventory data represent the process for which they are collected and how well that process represents the process of the system that is modelled. Good representativeness is particularly important for the most important processes of the system. Representativeness has three components – technological -, geographical – and timerelated representativeness, which interrelate and are all to be considered and met by the used data. 15.2.5.1 Technological representativeness (No corresponding ISO chapter but referring to a number of chapters) Poor or distorted technological representativeness for key processes The data used to represent the key processes of the system must be representative in terms of their technology to ensure that the data has the sufficient technological accuracy. Different technologies may result in identical products (e.g. diesel fuel), but the processing steps including the raw material bases e.g. may differ completely (e.g


Different technologies may result in identical products (e.g. diesel fuel), but the processing steps including the raw material bases e.g. may differ completely (e.g. biomass-based synthetic diesel vs. crude-oil based diesel). The use of data that lacks the correct technological representativeness can often be as wrong as using data from a completely different product. In addition and especially for comparative assertions a balanced representativeness is crucial. This is illustrated in two examples:  In a comparative LCA study commissioned by company A who wants their food packaging produced from plastic X compared to a competing product produced from metal Y. The consultant performing the study receives specific data for all of company A‟s own processes and the company supports the procurement of specific data from all of the main suppliers involved in the product chain


For the competing product, company A and its consultant have no specific information and the consultant is obliged to rely on generic data from third party databases for all key processes. The result is an (unintended) distorted technological representativeness that poses a great risk of misleading results.  In a comparative LCA study of vehicle fuel production technologies, the current very widespread technology A is compared to the planned new technology B, which at this point is still only working in laboratory scale. Using the available data for the two technologies leads to a distorted technological representativeness for the future situation, as the development and maturation levels of the technologies are not the same. Assuming the yields and efficiencies observed today in lab scale to be directly representative for the future commercial scale situation is not reasonable and some sort


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation of extrapolation is required but must be done with caution to avoid a misleading bias in the technological representativeness. This case is closely linked to time-related representativeness (see Section 15.2.5.3) 15.2.5.2 Geographical representativeness (No corresponding ISO chapter but referring to a number of chapters) Poor or distorted geographical representativeness The data used for the key processes must also be representative in terms of their geographical origin and coverage. The LCA practitioner performing the study must identify key processes and key assumptions that vary according to the geographical location and ensure the proper geographical representativeness for these


Geographical representativeness and technological representativeness are often related in the sense that poor geographical representativeness means that the applied data represents a different technology (mix) from what is applied in the system. Similarly as using data from a different technology route, also using data from different regions can lead to completely wrong results, as big differences in the inventories may exist. 15.2.5.3 Time-related representativeness (No corresponding ISO chapter but referring to a number of chapters) Poor or distorted time-related representativeness for key processes: The data used for the key processes must also be representative in terms of their timerelated origin (age). Again, there is a close relation to technological representativeness; as technology is developed and changed over time, a poor time-related representativeness often also means a poor technological representativeness


This is especially the case for fast developing technologies, e.g. in ITC systems, renewable energy systems, services, and the like. For basic materials and energy carriers these changes are much slower. Data sets should therefore inform about the validity (“expiry date”) of its inventory. Two examples:  In the above comparison of company A‟s plastic-based food packaging with the food packaging produced from metal Y, quoted in Section 15.2.5.1, part of the distortion in the representativeness of the applied data resides in a distorted time-related representativeness: The data of company A‟s own production and supply chain is quite recent and represents the current state of operation for all its own processes and data for suppliers is also recent. In contrast, the data for the competing food packaging is retrieved from databases or literature and as such typically at some years old, some of it potentially much older


In contrast, the data for the competing food packaging is retrieved from databases or literature and as such typically at some years old, some of it potentially much older. This bias in the time-related representativeness is followed by a further bias in technological representativeness due to the typical development of technology, typically to the advantage of the food packaging from company A.  In the identification of focus points and design recommendations for ecodesign of a refrigerator to be sold, used, and disposed off in Region X, an LCA is performed to find the hotspots of the life cycle. The refrigerator may be expected to have a lifetime of 15 years. In order to avoid misleading results on the impacts of the end-of-life, the data for the disposal and material recycling processes in Region X should be forecasted or at least taken from the present best available technology (BAT). This is to represent the most probable situation when the refrigerator ends its functional life


This is to represent the most probable situation when the refrigerator ends its functional life. Again, the timerelated representativeness is closely related to technological representativeness through the development of technology in time.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation 15.2.6 Consistency in comparison of systems and products (No corresponding ISO chapter but referring to a number of chapters) Inconsistent scoping of systems in comparative LCAs In order to avoid misleading results, it is important that the scoping is done consistently for the different parts of the system, or for the different systems in case of comparative LCAs. In particular in the case of comparative LCAs, inconsistent treatment of any of the scoping aspects covered by Sections 15.2.1-15.2.5 can easily lead to misleading results and conclusions,  if the compared products A and B do not provide the same functionalities due to an inappropriate definition of the functional unit,  if different modelling principles are applied in the analysis of the compared products A and B and e.g


marginal technologies used for key processes in the life cycle of product A while average technologies are assumed for the corresponding processes in the life cycle of product B (which is in addition also an example of inconsistent technological representativeness),  if the system boundaries are drawn in an inconsistent way, or  if the representativeness (technological, geographical or time-related) of the data differs relevantly for some of the key processes in the life cycle of products A and B. 15.3 Misleading interpretation (No corresponding ISO chapter but referring to a number of chapters) Introduction In the interpretation phase the results of the LCA study are appraised and interpreted in order to answer the questions posed as part of the goal definition or by the intended applications of the study


The outcome of the interpretation are be conclusions or recommendations that are to respect the intentions and restrictions of the goal and scope definition of the study and also take into account the appropriateness of the functional unit and system boundaries in relation to the goal. The interpretation must thus be closely linked to the goal which was defined in the beginning of the study and respect the limitations that the scoping puts on the validity domain of the results. Misleading interpretation occurs when: Interpreting the results beyond what is supported with the chosen scope definition An example of this form of misleading interpretation is when conclusions for specific cases (e.g. specific technology, specific use scenario, specific country) are generalised to be valid for broader cases (family of technologies, all uses, globally). An example:  In a comparative study of diapers the goal may be defined as “Comparison of reusable and single-use diapers in Country X”


An example:  In a comparative study of diapers the goal may be defined as “Comparison of reusable and single-use diapers in Country X”. In Country X the single-use diapers may be treated together with household waste, i.e. incinerated with recovery of the produced energy, where as the electricity used for washing the reusable diapers may be produced from stronger polluting energy sources. This specific combination may give the single-use diapers a competitive edge over multi-use diapers in Country X from an environmental point of view. If this conclusion was generalised to other countries or even the global scale, the LCA consultant performing the study would disregard


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation - the fact that the end-of-life of this type of product is crucial in the life cycle perspective, - that the waste treatment of diapers in Country X is far from the situation in other countries or on a global scale where land-filling of household waste is much more common. Generalisation of conclusions to other scopes will often be a misleading interpretation. Another type of misleading interpretation occurs when: Interpreting results beyond what they can support As part of the interpretation of comparative studies an analysis of the overall achieved accuracy and uncertainty should performed, at least qualitatively


In comparative studies, the difference in environmental impacts that is found between the compared alternatives is to be judged against the appraised uncertainty of the results in order to identify whether there is any significant difference. In the cases where the data does not support a quantitative uncertainty analysis, conclusions about superiority of one alternative over the other should still be justified by a discussion of the qualitative uncertainty of the results relative to the differences found between the alternatives and of any omissions that might change the dominance between the compared alternatives. This is to be done together with an appraisal of the accuracy of the results. An example:  A comparison of ball point pens shows that one type has less environmental impacts than the other in all examined impact categories, leading to the claim that “Pen xx” is better for the environment than “Pen YY”. The report shows that the differences are small, e.g


The report shows that the differences are small, e.g. less than 5 % in all impact categories examined, and no form for statistical treatment of the data has been performed in order to determine a level of significance and also the accuracy of the respective results has not be judged. The claim is thus not scientifically justified, and it is likely that the interpretation is misleading. 15.4 Misleading reporting and communication (No corresponding ISO chapter but referring to a number of chapters) The misleading interpretation of comparisons (e.g. in the above example of single-use and multiple-use diapers) might not necessarily be done by the consultant who performs the study or the commissioner, but be left to the user of the results: This is if the highly specific findings are presented in a way, where the limitations and assumptions are put into annexes and footnotes only and are not clearly stated directly in context of the presentation of conclusions and recommendations


Reporting and communication equally has to consider any limited technical and LCA methodological understanding of the addressees, e.g. of the general public. Conclusions and recommendations and the reference to limitations and assumption is hence to use the appropriate language and level of technicality for the target audience, ensuring that all targeted audience is appropriately informed about them.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation 15.5 Integrated example of misleading goal and scope definition and interpretation: cups for hot drinks246 (No corresponding ISO chapter but referring to a number of chapters) Starting point and goal definition The old cups used for hot drinks in the canteen at a large factory in country X are worn out. Company Y that owns the factory frequently uses claims of environmental sustainability in its marketing. Before purchasing new cups, the company thus wishes to investigate which solution is preferable from an overall environmental perspective


Before purchasing new cups, the company thus wishes to investigate which solution is preferable from an overall environmental perspective. Company Y considers the following alternative solutions: A.) Each employee gets personal own ceramic cup, brings it to the canteen takes it back to the work place and washes it by hand when deemed necessary B.) The canteen buys ceramic cups which stay in the canteen where they are washed by dishwashing machine. C.) The canteen uses single-use cups made from material Z. The cups are collected after use and treated together with household waste, i.e. transported to incinerator and burned with electricity production from the generated waste heat. Misleading functional unit and reference flow In a first attempt company Y asks a consultant perform a comparison of the environmental impacts of one ceramic cup (alternative A and B) and one single-use cup (alternative C)


This is an example of misleading definition of “functional unit”: it disregards the functionality of the products that are compared. In accordance with the goal of the company and the intended application of the results an appropriate functional unit might be: “Cup that can contain 2 dl of hot beverage (tea, coffee, bouillon) three times per day in one year (200 working days) for 1000 employees and serve as a drinking device”. With this functional unit the relevant reference flows would be 1000 ceramic cups for alternative A and B (assuming that the ceramic cups have the same average lifetime of 1 year for both use scenarios) and 6*105 single-use cups for alternative C, i.e. one ceramic cup versus 600 single use cups


one ceramic cup versus 600 single use cups. Misleading drawing of system boundaries Based on feedback from an involved supplier, the consultant realizes that in a comparative LCA it must be consistent in the drawing of system boundaries and since there are no impacts in the use stage of the single-use cup it decides to omit the use stage for all three alternatives from the study. This is an example of leaving out life cycle phases that are important for at least one of the compared alternatives: With the frequent washing of the ceramic cups (three times per day for alternative B and perhaps 1-3 times per day for alternative A depending on the hygiene of the individual employee) and the use of hot water and detergent in the dishwashing, the use stage is probably the most important for these two alternatives


This would have been revealed by the kind of screening based on simple calculations and easily available data or estimates that should always be carried out as a first iteration when performing an LCA. 246 This example is of course purely illustrative and virtual, including the results and conclusions that must not be misinterpreted as having any factual basis or even detailed analysis underneath.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation Misleading choice of impact categories For simplicity, company Y decides to concentrate on the carbon footprint of the three alternatives and decides to focus the data collection on the use of petrochemical fuels and feedstock in the different stages of the life cycles of the three alternatives. This narrow choice of impact categories is not in accordance with the goal to investigate the overall environmental impacts of the three alternatives. It causes misleading results in this case since two of the alternatives have potentially important other impacts from the detergents and organic load from the washing of the cups during the use stage in country X, where wastewater is discharged directly to a river even in several of the major cities across the country


These impacts are not revealed when only carbon footprint is assessed and the study may easily result in a wrong recommendation. Being informed about these limitations, the company decides to also include other impacts of relevance. Poor and distorted technological representativeness for key processes Company Y has found an old study of the environmental impacts from the production of ceramic cups containing all the data needed for this part of the LCA of alternatives A and B. The production covered by the study took place in a different part of the world but the cups are of a type similar to alternative A and B. For alternative C, company Y has to contact a major producer of these single-use cups and this producer provides the required information to company Y. Due to poor time-related and geographical representativeness of the data on the ceramic cups, also the technological representativeness must be expected to be poor


Due to poor time-related and geographical representativeness of the data on the ceramic cups, also the technological representativeness must be expected to be poor. In contrast, the technological, time-related and geographical representativeness is very good for the singleuse cups with data from the specific producer and supply chain of the single-use cups. This means that the representativeness of the production data is biased between the alternatives. In effect the recommendations of the study can be expected to be distorted, in this case towards favouring the alternative C. Misleading interpretation Based on the results company Y concludes that - contrary to what they expected - the single-use cups are preferable over the ceramic cup alternatives


Misleading interpretation Based on the results company Y concludes that - contrary to what they expected - the single-use cups are preferable over the ceramic cup alternatives. It turns out that even though a lot of energy resources are used to produce the many single-use cups, the energy recovery from their combustion in the end of life treatment in recently installed municipal incineration plants is rather efficient. Furthermore the canteen‟s dishwasher is rather old and inefficient, and in country X the electricity is mainly produced from lignite. Overall the energy account and carbon footprint give no clear preference and the other impacts from the discharge of the untreated dishwashing water in alternatives A and B tip the balance in favour of alternative C. Company Y concludes the superiority of single use cups and implements it in recommendations to the canteens in its factories around the world to replace ceramic cups and other tableware with single-use tableware


This is an example of interpreting the results far beyond what is supported with the chosen scope definition. The dominance of alternative C relied among other aspects on:  The efficient recovery of heat and generation of electricity at the waste incinerators where the cups were combusted after use and the coal-based power plants producing the electricity which is replaced by electricity from the incinerator


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation The lack of treatment of wastewater which means that the contents of detergents from washing the ceramic cups is discharged untreated directly into rivers of Country X  The inefficient dishwasher in the canteen of the factory in Country X. If these aspects are not representative of the situation in another country, the conclusion from country X will most likely not be valid here. Concluding remark This example also shows that most errors made by the company and consultant (and the related costs of changing the study and scope of data twice in its course) could have been avoided building on LCA experience. If done properly, the results would have been valid and hence the cost be justified.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 15 Annex D: Avoiding misleading goal and scope definition and results interpretation


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 16 Annex E: Addressing uncertainties in LCA 16 Annex E: Addressing uncertainties in LCA 16.1 Introduction and overview Introduction Life cycle assessments are often comparative, i.e. performed in order to analyse differences between products, processes or other systems. The construction and analysis of the systems involves potential sources of uncertainties, not only in the case of future studies, but also in studies describing the present situation. In order to determine whether the apparent differences between the compared alternatives are real (statistically significant), it is necessary to perform an assessment of the uncertainties accompanying the results


The following sections give a brief presentation of some of the concepts and approaches that can be applied for addressing uncertainties in LCA Overview Three main sources of uncertainty have been addressed:  stochastic uncertainty  choice uncertainty  lack of knowledge of the studied system. The stochastic uncertainties of the inventory data and LCIA methods must be considered jointly with the important choice-related uncertainties in order to determine how they propagate into the final results of the LCA. The stochastic uncertainty of final results can be assessed in two fundamentally different ways – through an analytical solution or through simulation. Uncertainty calculation is applied to quantify stochastic parameter uncertainties of data. Monte-Carlo Simulation is an especially suitable method to do so in LCA, as it allows varying many factors in parallel and calculating the overall resulting uncertainty on the system level


Monte-Carlo Simulation is an especially suitable method to do so in LCA, as it allows varying many factors in parallel and calculating the overall resulting uncertainty on the system level. When performing Monte Carlo analysis it is recommended to consider the correlation among the various data values and impact factors if it is known. The outcome of the stochastic uncertainty calculation should not be over-interpreted; it also may have high degree of uncertainty and especially of bias as it is not capturing systematic uncertainty and gaps in modelling and data


16.2 Types and sources of uncertainty in LCA Overview Uncertainties in the results of an LCA originate in  the data that is used in the inventory analysis to represent the elementary flows for all the processes in the system  the data that is used in the impact assessment for translating the inventory flows into environmental impact scores  the assumptions that are made when constructing the system, (related to the representativeness of the processes that are used in the model)


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 16 Annex E: Addressing uncertainties in LCA the choices that are made on central decisions like allocation key, choice impact assessment methodology or on which future developments are considered in future studies The uncertainty of the data for elementary flows is statistic uncertainty, i.e. of a stochastic nature. The same holds true for impact assessment factors within a given impact assessment methodology, while the uncertainty introduced by the key assumptions and choices is of a different nature in that a number of discrete outcomes are possible


Stochastic data The stochastic uncertainty of process data (like emissions and input of resources) and assessment data (like characterisation factors) means that they are adequately described in traditional statistical terms providing  a measure of the mean,  a measure of the variation around the mean, and  information about the type of distribution that the data follows. Measured data are often assumed to follow a normal distribution or a logarithmic normal distribution (in which case the logarithm of the data value follows a normal distribution). For normal distributed data, the average and the standard deviation are used to describe the mean and the variation around the mean. Choices In contrast to the statistic uncertainty, the variation accompanying choices that are made when performing the LCA is of a discrete nature, i.e. several specific options are possible while options in between these are not


several specific options are possible while options in between these are not. In the case of LCAs studying future situations, a number of possible and probable future settings is defined and investigated, and only these are considered relevant, not the potential futures that lie in between. In the performance of an LCA study ,there are also potentially a number of methodological choices including:  LCI modelling principles  LCI method approaches (and normalisation basis and weighting set, if included)  Cut-off decisions and other system boundary settings  Choice of LCI data sets to represent the background processes  Choice of impact categories and LCIA methods  Other assumptions (e.g. use of upper or lower calorific value, modelling of future processes, etc.) Even within an LCIA methodology there may be choices to make in terms of time perspective or cultural perspective


use of upper or lower calorific value, modelling of future processes, etc.) Even within an LCIA methodology there may be choices to make in terms of time perspective or cultural perspective. Due to the discrete nature of the choice-related uncertainties, these are not described by a continuous statistical distribution but rather modelled as separate settings for the LCA (e.g. as distinct scenarios). Secondly, there are the main choices that have the potential to influence the precision of the final results of the LCA. These can be significant choices are to be identified in a different way than the main contributors: by running the different possible choices as scenarios and comparing the scenario results.


ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance First edition 16 Annex E: Addressing uncertainties in LCA Ignorance A third source of uncertainty is the error attributable to ignorance, i.e. the lack of knowledge about the system, leading to omission of data or incorrect assumptions about processes or elementary flows. Ignorance is related to choice uncertainty in the sense that it shows discrete behaviour but since it is not realized, it cannot be dealt with in the way that choices are dealt with. It is not handled by quantitative uncertainty assessment, but may be revealed by a qualified peer review. 16.3 Aggregating uncertainties over the life cycle Overview The stochastic uncertainties of the inventory and assessment data must be known together with the important choice-related uncertainties in order to determine how they propagate into the final results of the LCA