ASTM E3199-22a

Standard Guide for Alternative Allocation Approaches to Modeling Input and Output Flows of Secondary Materials and Related Recycling Scenarios in Life Cycle Assessment

SIGNIFICANCE AND USE
4.1 LCAs can help to identify some of the potential environmental impacts of products or services throughout the entire life cycle. In a life cycle inventory analysis, emissions into the air; discharges into the water and soil; and product, material, and energy flows at all stages of a product’s life cycle are compiled and quantified. The resulting life cycle impact assessment (LCIA) converts the quantified parameters into environmental impact categories.  
4.2 Options for managing products at their end of life (EOL) can include, but are not limited to, re-using, recycling, recovering, remanufacturing, converting to energy, incinerating, composting, combustion, digestion/respiration, or discarding as waste. Materials enter subsequent life cycle(s), either in the same or in other applications, reducing the input of primary raw material and impacting the amount of waste. LCA will be required to determine if environmental impact reductions are expected to be realized and to what extent for each specific application. The end-of-life management can impact the overall life cycle assessment.  
4.3 The application of an allocation method for recycling in life cycle assessments is useful in assessing potential environmental impacts, which may be either beneficial or adverse.  
4.4 As part of good LCA practice, practitioners should consider recycling in the sensitivity analysis.  
4.5 LCA practitioners are expected to ensure consistency and conformance with the relevant provisions of ISO standards.  
4.6 Allocation for recycling can split the flows and impacts between two different product systems.
SCOPE
1.1 This guide illustrates alternative allocation approaches that provide options for modeling secondary material flows and related recycling scenarios within a life cycle assessment (LCA) study. It helps practitioners characterize and understand materials recycling across industries; provides the available methodologies for consideration of the environmental impacts that are attributed to material and product flows in LCA; aids in assessment of the overall life cycle of systems and understanding of materials; and supports life cycle management.  
1.2 The guide is not intended to contradict or circumvent the LCA provisions of ISO 14025, ISO 14040, ISO 14044, ISO 14067, ISO/TR 14049, or ISO 21930. When conflicts arise related to LCA, the guidance of those ISO standards takes precedence.  
1.3 The following seven material-specific appendixes are included:    
Title  
Appendix  
Recycling of Copper  
Appendix X1  
Recycling of Flue Gas Desulfurization (FGD) Gypsum  
Appendix X2  
Recycling of Glass  
Appendix X3  
Recycling of Plastics  
Appendix X4  
Recycling of Post-consumer (PC) Gypsum  
Appendix X5  
Recycling of Stainless Steel  
Appendix X6  
Recycling of Supplementary Cementitious Materials  
Appendix X7  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 13.020.60 - Product life-cycles
• ICS: 13.030.50 - Recycling
• Technical Committee: E60 - Sustainability
• Drafting Committee: E60.80 - General Sustainability Standards

Relations

• Refers: ASTM A941-24 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Mar-2024
• Refers: ASTM A941-17 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Sep-2017
• Refers: ASTM E2114-17 - Standard Terminology for Sustainability Relative to the Performance of Buildings
• Effective Date: 01-Feb-2017
• Refers: ASTM A941-15 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Nov-2015
• Refers: ASTM A941-13b - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Jun-2013
• Refers: ASTM A941-13a - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-May-2013
• Refers: ASTM A941-13 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Apr-2013
• Refers: ASTM A941-10a - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Jun-2010
• Refers: ASTM A941-10 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 15-Apr-2010
• Refers: ASTM A941-09a - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Dec-2009
• Refers: ASTM E2114-08 - Standard Terminology for Sustainability Relative to the Performance of Buildings
• Effective Date: 01-Nov-2008
• Refers: ASTM E2114-06a - Standard Terminology for Sustainability Relative to the Performance of Buildings
• Effective Date: 01-Dec-2006
• Refers: ASTM A941-06a - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 15-Jun-2006
• Refers: ASTM A941-06 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 15-Mar-2006
• Refers: ASTM E2114-06 - Standard Terminology for Sustainability Relative to the Performance of Buildings
• Effective Date: 15-Feb-2006

Overview

ASTM E3199-22a, titled "Standard Guide for Alternative Allocation Approaches to Modeling Input and Output Flows of Secondary Materials and Related Recycling Scenarios in Life Cycle Assessment," provides comprehensive guidance for life cycle assessment (LCA) practitioners on modeling secondary material flows and recycling scenarios. Issued by ASTM International, this standard is designed to help organizations evaluate potential environmental impacts linked to the recycling and reuse of materials across product life cycles. By illustrating alternative allocation methodologies, the standard offers practitioners a framework for consistent and transparent assessment and reporting as well as support for sustainability initiatives and compliance with ISO standards.

Key Topics

• Life Cycle Assessment (LCA) Context: The standard outlines how LCA is used to quantify environmental impacts, material and energy flows, and emissions across a product’s life-from raw material extraction, production, and use, through end-of-life management and recycling.

• Allocation Approaches: Various methods for assigning environmental impacts to products that incorporate recycled materials or generate secondary flows are presented, including:

  • Recycled Content or “Cutoff” Approach: This method allocates impacts only to primary material and assigns no impact to secondary materials at the manufacturing stage. It is especially relevant where recycled content is significant.
  • End-of-Life Recycling Approach: Based on system expansion, this approach assigns environmental benefits of recycling to the product’s original life cycle, considering impacts of collection and processing at the end of life.
  • Hybrid (50/50) Approach: This splits impacts between product systems (e.g., both original and next products using recycled material), allowing for flexible ratios (e.g., 20/80, 60/40).

• Material-Specific Guidance: The standard includes appendixes on copper, gypsum, glass, plastics, stainless steel, and supplementary cementitious materials, providing sector-specific recycling methodologies.

• Alignment with International Standards: ASTM E3199-22a is designed to maintain consistency with key ISO standards, such as ISO 14025, ISO 14040, ISO 14044, ISO 14067, and ISO 21930.

• Best Practices in LCA: The standard encourages practitioners to perform sensitivity analyses, ensure data quality, and transparently justify their choice of allocation method based on industry context, material supply-demand dynamics, and product life span.

Applications

ASTM E3199-22a has practical value for a variety of industries and stakeholders involved in sustainability, environmental product declarations (EPDs), and materials management:

• Sustainable Product Design: Helps manufacturers assess alternatives for material selection and end-of-life recycling, leading to lower environmental footprints.
• Environmental Reporting: Facilitates compliance with EPD schemes and reliable reporting of recycled content or recyclability in construction, manufacturing, automotive, and packaging sectors.
• Supply Chain Transparency: Supports clear communication of recycled material flows between suppliers, manufacturers, and customers.
• Regulatory Compliance: Assists organizations in aligning LCA studies and sustainability claims with internationally accepted methods and ISO requirements.
• Sector-Specific Implementation: Through industry-focused appendices, practitioners can model recycling scenarios for materials such as copper, glass, plastics, gypsum, stainless steel, and cementitious materials more effectively.

Related Standards

To ensure comprehensive and internationally harmonized LCA practice, ASTM E3199-22a should be used alongside the following standards:

• ISO 14040 / ISO 14044 – LCA Principles, Framework, Requirements, and Guidelines
• ISO 14025 – Type III Environmental Declarations
• ISO 14067 – Carbon Footprint of Products
• ISO 21930 – EPDs for Construction Products
• ISO 15270 – Plastics Recovery and Recycling Guidelines
• ASTM E2114 – Terminology for Sustainability in Buildings
• ASTM A941 – Terminology Relating to Steel and Alloys

Keywords: ASTM E3199-22a, life cycle assessment, allocation approach, secondary materials, recycling, end-of-life, recycled content, environmental impact, sustainability, ISO standards, material flows

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3199 − 22a
Standard Guide for
Alternative Allocation Approaches to Modeling Input and
Output Flows of Secondary Materials and Related Recycling
Scenarios in Life Cycle Assessment
This standard is issued under the fixed designation E3199; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This guide illustrates alternative allocation approaches
mendations issued by the World Trade Organization Technical
thatprovideoptionsformodelingsecondarymaterialflowsand
Barriers to Trade (TBT) Committee.
related recycling scenarios within a life cycle assessment
(LCA) study. It helps practitioners characterize and understand
2. Referenced Documents
materials recycling across industries; provides the available
2.1 ASTM Standards:
methodologies for consideration of the environmental impacts
A941 TerminologyRelatingtoSteel,StainlessSteel,Related
that are attributed to material and product flows in LCA; aids
Alloys, and Ferroalloys
in assessment of the overall life cycle of systems and under-
E2114 Terminology for Sustainability Relative to the Perfor-
standing of materials; and supports life cycle management.
mance of Buildings
1.2 Theguideisnotintendedtocontradictorcircumventthe 3
2.2 ISO Standards:
LCA provisions of ISO 14025, ISO 14040, ISO 14044, ISO
ISO14001 Environmentalmanagementsystems—Require-
14067, ISO/TR 14049, or ISO 21930. When conflicts arise
ments with guidance for use
related to LCA, the guidance of those ISO standards takes
ISO 14025 Environmental labels and declarations — Type
precedence.
III environmental declarations — Principles and proce-
1.3 The following seven material-specific appendixes are
dures
included: ISO 14040 Environmental management — Life cycle as-
sessment — Principles and framework
Title Appendix
Recycling of Copper Appendix X1
ISO 14044 Environmental management — Life cycle as-
Recycling of Flue Gas Desulfurization (FGD) Gypsum Appendix X2
sessment — Requirements and guidelines
Recycling of Glass Appendix X3
ISO/TR 14049 Environmental management — Life cycle
Recycling of Plastics Appendix X4
Recycling of Post-consumer (PC) Gypsum Appendix X5
assessment — Illustrative examples on how to apply ISO
Recycling of Stainless Steel Appendix X6
14044 to goal and scope definition and inventory analysis
Recycling of Supplementary Cementitious Materials Appendix X7
ISO 14067 Greenhouse gases — Carbon footprint of prod-
1.4 The values stated in SI units are to be regarded as
ucts — Requirements and guidelines for quantification
standard. The values given in parentheses after SI units are
ISO 15270 Plastics — Guidelines for the recovery and
provided for information only and are not considered standard.
recycling of plastics waste
1.5 This standard does not purport to address all of the
ISO 21930 Sustainability in buildings and civil engineering
safety concerns, if any, associated with its use. It is the
works — Core rules for environmental product declara-
responsibility of the user of this standard to establish appro-
tions of construction products and services
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
3.1 Definitions—Fordefinitionsofgeneraltermsusedinthis
dance with internationally recognized principles on standard-
guide, refer to Terminology E2114. For general terminology
1 2
This guide is under the jurisdiction ofASTM Committee E60 on Sustainability For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and is the direct responsibility of Subcommittee E60.80 on General Sustainability contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2022. Published October 2022. Originally the ASTM website.
approved in 2022. Last previous edition approved in 2022 as E3199–22. DOI: Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/E3199-22A. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3199 − 22a
related to life cycle assessment, refer to ISO 14040. 5. Summary of Guide (LCA)
3.1.1 post-consumer, n—descriptive term covering material,
5.1 While existing guidelines and standards (for example,
generated by the end-users of products, that has fulfilled its
ISO 14040 and ISO 14044) consistently recommend allocation
intended purpose or can no longer be used (including material
to account for the environmental impacts of recycling in LCA,
returned from within the distribution chain). ISO 15270
there is no further guidance on the recommended methodolo-
gies that apply across industries and sectors outside the
3.1.2 secondary materials, n—material recovered from pre-
building and construction sector (ISO 21930). Due to the
vious use or recovered from waste derived from another
varietyofproductsthatarerecycledandthedifferencesoftheir
product system and used as an input in another product system.
life cycles, several allocation methodologies have been devel-
3.1.2.1 Discussion—Example: recycled scrap metal,
oped and are currently applied globally. There is no one
crushed concrete, glass cullet, recycled wood chips, recycled
approach that can be consistently recommended for all mate-
plastic granulate.
rials and products. ISO has standardized its rules for allocation
3.1.2.2 Discussion—Secondary material is measured at the
regarding Environmental Product Declarations (EPD) for
point (that is, system boundary) where the secondary material
Building and Construction Products in ISO 21930 and ISO
enters the product system from another product system. ISO
14025, the general EPD standard. This guide does not override
these rules.
3.2 Definitions of Terms Specific to This Standard:
5.2 Appendix X1 to Appendix X7 provide examples of
3.2.1 environmental impact, n—change to the environment,
existing methodologies applied in different industries for
whether adverse or beneficial, wholly or partially resulting
different recycled raw materials and products. These examples
from an organization’s activity.
complement specific guidance and case studies for recycling in
3.2.1.1 Discussion—Modified from ISO 14001.
LCAas provided in ISO/TR 14049 and go beyond the specific
3.3 Acronym:
focus of ISO 14067 on carbon footprinting.
3.3.1 ISO—International Organization for Standardization
6. Summary of Methods
6.1 There are three primary frameworks for modeling end-
4. Significance and Use
of-life recycling in LCA, which are used most commonly by
4.1 LCAs can help to identify some of the potential envi-
practitioners globally. For all these frameworks, the guidelines
ronmentalimpactsofproductsorservicesthroughouttheentire
for setting system boundaries should be in line with the ISO
life cycle. In a life cycle inventory analysis, emissions into the
14040 series standards. The selection of a modeling approach
air; discharges into the water and soil; and product, material,
for secondary materials and recycling scenarios should reflect
and energy flows at all stages of a product’s life cycle are
the goal and scope of the LCA study.
compiled and quantified. The resulting life cycle impact
6.1.1 The Recycled content/“cutoff” approach has been
assessment (LCIA) converts the quantified parameters into
utilized in LCA for many years due to its simplicity and
environmental impact categories.
modeling ease.The practitioner essentially places no beneficial
4.2 Optionsformanagingproductsattheirendoflife(EOL)
environmentalimpactontherecycledcontentintheproduction
can include, but are not limited to, re-using, recycling, phase of the life cycle of the product being studied, and
recovering, remanufacturing, converting to energy,
recycled materials collected at the end of life are sent to the
incinerating, composting, combustion, digestion/respiration, or next product system with no environmental impact (beneficial
discarding as waste. Materials enter subsequent life cycle(s),
or adverse). The end-of-life collection remains in product
eitherinthesameorinotherapplications,reducingtheinputof system A. The impacts arising from the end-of-life collection
primary raw material and impacting the amount of waste. LCA
processes/activities remain within and are attributed to the
will be required to determine if environmental impact reduc- primary product system.
tions are expected to be realized and to what extent for each
NOTE 1—This approach is mandated in ISO 21930.
specific application. The end-of-life management can impact
6.1.2 The end-of-life recycling approach is based on the
the overall life cycle assessment.
concept in ISO 14040 of system expansion. Essentially, the
4.3 The application of an allocation method for recycling in
practitioner expands the product systemAboundary in order to
life cycle assessments is useful in assessing potential environ-
give credit to the first life cycle for the beneficial impact of
mental impacts, which may be either beneficial or adverse.
utilizing a material that is recyclable in its initial use. The
material for recycling is a beneficial impact given to product
4.4 As part of good LCA practice, practitioners should
systemA. The end-of life approach covers end-of-life material
consider recycling in the sensitivity analysis.
for recycling. It potentially acknowledges recycling that has
4.5 LCA practitioners are expected to ensure consistency
notyettakenplace.Theend-of-lifeapproachisoftenappliedto
and conformance with the relevant provisions of ISO stan-
open-loop product systems where materials are recycled and
dards.
enter into subsequent product systems. When this approach is
4.6 Allocation for recycling can split the flows and impacts used, it should not circumvent other relevant ISO 14000 series
between two different product systems. standards.
E3199 − 22a
FIG. 1 Material Flows in Common, Idealized Product System
6.1.3 The 50/50 (hybrid) approach uses a combined ap- proaches on how to allocate/distribute the environmental
proach to distribute environmental impacts between product
impacts related to the material recycling between the product
systems. It takes the environmental impacts from end-of-life systems A and B.
recycling and collection/sorting, and the environmental impact
7.2 The recycled content approach (6.1.1 and Fig. 2) builds
for the material recycling is divided equally between product
on the assumption that the secondary material input used in
system A and product system B. Other splits (for example,
productsystemAisfreeofenvironmentalimpactsexceptthose
20/80 or 60/40) can also be used and depend on the specific
thatarerelatedtorequiredactivitiessuchascollection,sorting,
product system and use/recycling patterns.
processing, and transport of the materials. In consequence,
6.1.4 There are also other approaches available including
there are no environmental impacts from recycling the mate-
the waste valuation approach, which accounts for the value of
rials after use that can be allocated to product system A. The
the material at the end of life (1).
recycled content approach instead acknowledges the recycling
6.1.5 More detailed guidance on the methodological aspects
that has taken place.
of the modeling of reuse, recycling, and recovery of energy are
provided by the International Reference Life Cycle Data
7.3 The end-of-life approach (6.1.2) assumes that the sec-
System (ILCD) Handbook of the European Commission (2).
ondary material input has the same environmental impacts as
the primary raw materials. It is therefore modeled as though
7. Synthesis
100 % of the input is from primary raw materials. The
7.1 The following section demonstrates how the approaches
environmental impacts associated with collection, sorting,
described in Section 6 include recycling in LCAs and how
transport, and processing are considered, as well as the
impacts associated with recycling are distributed over the
environmental impacts related to the replacement of primary
product systems involved. The approaches for including recy-
raw materials with recycled materials. All impacts related to
cling in LCAs are applied to a generic production system.
recycling are allocated to product system A, as shown in Fig.
When changes in the inherent properties of materials occur,
3. The end-of-life approach is often used for raw materials and
LCApractitionersshouldtakethoseintoaccountinaccordance
product systems where recycling is significant but does not
with the guidance provided in the 2013 PEF Guidance docu-
necessarily take place in the same product system (“open-loop
ment of the European Commission (3). Product system A is
recycling”), which is different than “closed-loop recycling”
described in Fig. 1. This product system consists of 60 %
where recycling takes place in the same product system. For
primary material and 40 % recycled material inputs. Eighty
products with an extended lifetime, the end-of-life approach
percent of the material from the product system is collected at
acknowledges the potential environmental impacts from future
its end of life and recycled, 20 % is not recycled. Half of the
recycling.
recycled material goes into the same product system A,
7.4 The 50/50 approach (6.1.3) describes a distribution of
whereas the other half goes into another product system B.
environmental impacts over two product systemsAand B.The
Environmental impacts can occur. There are different ap-
environmental impacts resulting from recycling, preparatory
activities (for example, sorting, collection), and the recycling
4 processes (processing) are distributed equally over both the
The boldface numbers in parentheses refer to a list of references at the end of
this standard. product systems. It also is possible to adjust the environmental
E3199 − 22a
FIG. 2 Recycled Content Approach
FIG. 3 End-of-life Approach
impacts distribution (for example, 20/80 or 40/60) with appro- 8.3.3.1 Feasibility and practicality of the separation process
priate justification. A 50/50 approach is shown in Fig. 4. for recycling.
8.3.4 Typical product service life.
8. Appendix Preparation
8.3.5 Potential changes in material properties during use
and recycling.
8.1 This section provides the expected format and content
for appendixes and the order in which each section should 8.3.6 Collection practices and the recycling process.
appear.All appendix examples are expected to be consistent in
8.4 A simplified flow chart as illustrated in Section 7.
structure and provide practitioners with concise information.
8.5 Some of the parameters mentioned above influence the
They should not exceed two pages in length.
choice of methodology. The approach for including recycling
8.2 Provide a description of the industry or the material
into LCAshould be stated and justified. The examples in 8.5.1
discussed in the appendix.
show how these parameters help to identify the appropriate
8.3 Explain the implications for LCA studies including the approach.
standard recycling practices and relevant parameters influenc- 8.5.1 Supply and Demand Examples:
ing the modeling approach, such as: 8.5.1.1 The end-of life approach can promote increased
8.3.1 Supply and demand of the material. collectionandrecyclingefficienciesformaterialswhengeneral
8.3.2 Specific properties and use patterns. demand is steadily growing but the supply of recycled raw
8.3.3 Condition of material, whether a physical or chemical materials is more limited relative to that rate of growth due to
separation from other materials is required for recycling. a long product life, as stated in Bergsma et al (4).
E3199 − 22a
FIG. 4 50/50 Approach
8.5.1.2 The recycled content approach is often applied for available to support inclusion of the appendix and provide
those products where supply and demand are in balance or practitioners with additional background information.
where supply exceeds demand.
NOTE2—Allreferencesthatarenotstandardsarelistedattheendofthe
8.5.2 Lifetime of Products Examples:
standardguideinaccordancewithASTMformat.Copiesofthereferenced
8.5.2.1 For products with an extended lifetime, the end-of-
documents should be supplied with the appendix submission. The refer-
life approach acknowledges the potential beneficial environ-
enced document list is not considered part of the appendix length.
mental impacts from future recycling.
8.5.2.2 The recycled content approach instead acknowl- 9. Keywords
edges the recycling that has taken place.
9.1 50/50 (hybrid); allocation; cutoff approach; end-of-life;
8.6 Third-party documentation or references such as Prod- environmental impacts, life cycle assessment (LCA); recycled;
uctCategoryRulesorjournalarticlesshouldbeprovidedwhen recycled content; recycling; sustainability
APPENDIXES
(Nonmandatory Information)
X1. RECYCLING OF COPPER:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X1.1 Copper Use conductors and sheet for roofing applications.The remainder is
mainly used in the form of alloys, where it is mixed with other
X1.1.1 Copper is used in many applications, including
metals like zinc for brass and tin for bronze.
electricity generation and transmission, electrical and transport
devices, and construction materials. Copper use is increasing
X1.2 Copper Recycling Pathways
on a global scale, and recycling plays an important role in
meeting this demand. On average, copper contains 30 % X1.2.1 High copper content products can be recycled di-
recycled content globally (5).
rectly into new products by direct melting and reshaping,
without the need to be re-refined to copper cathode first. This
X1.1.2 It is estimated that two-thirds of the 550 million tons
is also valid for end-of-life materials for recycling made from
of copper produced since 1900 are still in productive use (5).
alloys like brass or bronze, when collected and sorted in
Of this amount, approximately 70 % is used for electrical
mono-fraction. As a result, copper and its alloys belong to a
applications and 30 % for nonelectrical applications. Around
group of metals where effective recycling of scrap directly into
45 % is used in power generation and transmission, 20 % in
new products is well established. In addition, even scrap with
construction, 12.5 % in appliances and electronics, 12.5 % in
less than 1 % copper content can be used as a replacement for
transport, and 10 % in other applications.
primarycoppersources(oreandconcentrate).Thepotentialfor
X1.1.3 A large percentage (approximately 50 %) of copper copper to be removed from copper-containing scrap is not
is used in a near pure form (>99.9 % copper content). This dependent on the concentration of copper in the mix (Fig.
includes copper products such as copper wire for electrical X1.1).
E3199 − 22a
FIG. X1.1 Recycling Paths of End-of-life Products Made from Copper Materials
X1.3 Modeling Recycling of Copper in LCA come, as demonstrated by copper demand projections linked to
the growing electric vehicle and electrification trends.
X1.3.1 The EOL materials for recycling from copper prod-
Therefore, the end-of-life modeling approach is typically used
uct systems are almost always fed back into the metal
for copper (6). However, the practitioner should take into
production cycle, be it in the primary plants, secondary plants,
account market growth and scrap demand and ensure align-
or semi-fabrication, such as rod, tube, or wire. This is due both
ment with ISO 14040 series standards when undertaking a
to its recyclability as well as its value. The final product of
study, in order to confirm this approach and ensure justifica-
copper recycling is identical to primary copper (for both the
tion.
primary and secondary smelter routes) when refined into
purified copper. Similarly, copper will be similar in its prop-
X1.3.2 As shown in Fig. X1.1, recycling is part of both the
erties to the original scrap material entering the fabrication
primaryandsecondaryproductionofcoppercathode.Aslosses
process for semi-fabrication. In addition, the copper scrap
are dependent on technological production processes, a certain
market has been historically not in oversupply, thus EOL
amount of primary material (for example, cathode) will still be
materials for recycling from each product will substitute for
necessary in fabrication processes of products made from
primarymaterialandnotcompetewithotherEOLmaterialsfor
copper materials.
recycling. This is likely to remain the case for many years to
X2. RECYCLING OF FGD GYPSUM:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X2.1 FGD Gypsum Overview X2.2 Implications for Life Cycle Assessment
X2.1.1 Flue gas desulfurization (FGD) gypsum X2.2.1 LCA studies incorporating FGD gypsum use the
(CaSO ·2H O) is used as a raw material for the production of recycled content approach applying no environmental impacts
4 2
gypsum panel products in place of mined natural gypsum. As to the FGD material. This approach is appropriate for a
a co-product of electricity generation in coal-fired power material that is essentially the byproduct of a pollution-control
plants, FGD gypsum is produced in the SO scrubbing opera- system and for which significant portions of the material have
tions associated with stack emissions. FGD gypsum is substi- no commercial use and are currently sent to landfill. The
tuted on an equal molar basis with natural gypsum in gypsum approach applied in the LCA modeling of FGD gypsum in
panel production. For FGD gypsum to be used in the produc- LCA is shown in Fig. X2.1. The modeling of FGD gypsum
tion of gypsum board, it should be dewatered prior to shipment should include environmental impacts of de-watering at the
to the gypsum board manufacturing plant. FGD gypsum electrical facility and transportation of the FGD gypsum to the
typically arrives at the gypsum board manufacturing plant with gypsum board or manufacturing site (7).
a higher moisture content than natural gypsum requiring X2.2.1.1 SomedewateringoftheFGDgypsumoccursatthe
additional drying energy prior to calcination to produce stucco generation plant, and any energy associated with this should be
suitable for producing gypsum board. taken into account (8).
E3199 − 22a
FIG. X2.1 Simplified Scheme for Recycling of FGD Gypsum
X3. RECYCLING OF GLASS:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X3.1 Background X3.2.2 The post-consumer recycling pathway consists of
the following steps:
X3.1.1 Glass is used in many applications all around the
X3.2.2.1 Recyclableglassmaterialsarecollectedatresiden-
world, the most common being for packaging of food and
tial curbside bins, business recycling locations, or local recy-
beverages, for fenestration, and for thermal insulation. Glass,
which is not lost due to breakage and is in a form amenable to cling government drop-off centers. These may be sorted at the
recycling, may be recycled many times for the same compo- initial location (single stream) or may be mixed recycling.
sition. In many cases, compared to raw mineral materials,
X3.2.2.2 The mixed recy
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E3199 − 22 E3199 − 22a
Standard Guide for
Alternative Allocation Approaches to Modeling Input and
Output Flows of Secondary Materials and Related Recycling
Scenarios in Life Cycle Assessment
This standard is issued under the fixed designation E3199; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide illustrates alternative allocation approaches that provide options for modeling secondary material flows and related
recycling scenarios within a life cycle assessment (LCA) study. It helps practitioners characterize and understand materials
recycling across industries; provides the available methodologies for consideration of the environmental impacts that are attributed
to material and product flows in LCA; aids in assessment of the overall life cycle of systems and understanding of materials; and
supports life cycle management.
1.2 The guide is not intended to contradict or circumvent the LCA provisions of ISO 14025, ISO 14040, ISO 14044, ISO 14067,
ISO/TR 14049, or ISO 21930. When conflicts arise related to LCA, the guidance of those ISO standards takes precedence.
1.3 The following seven material-specific appendixes are included:
Title Appendix
Recycling of Copper Appendix X1
Recycling of Flue Gas Desulfurization (FGD) Gypsum Appendix X2
Recycling of Glass Appendix X3
Recycling of Plastics Appendix X4
Recycling of Post-consumer (PC) Gypsum Appendix X5
Recycling of Stainless Steel Appendix X6
Recycling of Supplementary Cementitious Materials Appendix X7
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
This guide is under the jurisdiction of ASTM Committee E60 on Sustainability and is the direct responsibility of Subcommittee E60.80 on General Sustainability
Standards.
Current edition approved May 1, 2022Oct. 1, 2022. Published June 2022October 2022. Originally approved in 2022. Last previous edition approved in 2022 as E3199–22.
DOI: 10.1520/E3199-22.10.1520/E3199-22A.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3199 − 22a
2. Referenced Documents
2.1 ASTM Standards:
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
E2114 Terminology for Sustainability Relative to the Performance of Buildings
2.2 ISO Standards:
ISO 14001 Environmental management systems — Requirements with guidance for use
ISO 14025 Environmental labels and declarations — Type III environmental declarations — Principles and procedures
ISO 14040 Environmental management — Life cycle assessment — Principles and framework
ISO 14044 Environmental management — Life cycle assessment — Requirements and guidelines
ISO/TR 14049 Environmental management — Life cycle assessment — Illustrative examples on how to apply ISO 14044 to
goal and scope definition and inventory analysis
ISO 14067 Greenhouse gases — Carbon footprint of products — Requirements and guidelines for quantification
ISO 15270 Plastics — Guidelines for the recovery and recycling of plastics waste
ISO 21930 Sustainability in buildings and civil engineering works — Core rules for environmental product declarations of
construction products and services
3. Terminology
3.1 Definitions—For definitions of general terms used in this guide, refer to Terminology E2114. For general terminology related
to life cycle assessment, refer to ISO 14040.
3.1.1 post-consumer, n—descriptive term covering material, generated by the end-users of products, that has fulfilled its intended
purpose or can no longer be used (including material returned from within the distribution chain). ISO 15270
3.1.2 secondary materials, n—material recovered from previous use or recovered from waste derived from another product system
and used as an input in another product system.
3.1.2.1 Discussion—
Example: recycled scrap metal, crushed concrete, glass cullet, recycled wood chips, recycled plastic granulate.
3.1.2.2 Discussion—
Secondary material is measured at the point (that is, system boundary) where the secondary material enters the product system from
another product system. ISO 21930
3.2 Definitions of Terms Specific to This Standard:
3.2.1 environmental impact, n—change to the environment, whether adverse or beneficial, wholly or partially resulting from an
organization’s activity.
3.2.1.1 Discussion—
Modified from ISO 14001.
3.3 Acronym:
3.3.1 ISO—International Organization for Standardization
4. Significance and Use
4.1 LCAs can help to identify some of the potential environmental impacts of products or services throughout the entire life cycle.
In a life cycle inventory analysis, emissions into the air; discharges into the water and soil; and product, material, and energy flows
at all stages of a product’s life cycle are compiled and quantified. The resulting life cycle impact assessment (LCIA) converts the
quantified parameters into environmental impact categories.
4.2 Options for managing products at their end of life (EOL) can include, but are not limited to, re-using, recycling, recovering,
remanufacturing, converting to energy, incinerating, composting, combustion, digestion/respiration, or discarding as waste.
Materials enter subsequent life cycle(s), either in the same or in other applications, reducing the input of primary raw material and
impacting the amount of waste. LCA will be required to determine if environmental impact reductions are expected to be realized
and to what extent for each specific application. The end-of-life management can impact the overall life cycle assessment.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
E3199 − 22a
4.3 The application of an allocation method for recycling in life cycle assessments is useful in assessing potential environmental
impacts, which may be either beneficial or adverse.
4.4 As part of good LCA practice, practitioners should consider recycling in the sensitivity analysis.
4.5 LCA practitioners are expected to ensure consistency and conformance with the relevant provisions of ISO standards.
4.6 Allocation for recycling can split the flows and impacts between two different product systems.
5. Summary of Guide (LCA)
5.1 While existing guidelines and standards (for example, ISO 14040 and ISO 14044) consistently recommend allocation to
account for the environmental impacts of recycling in LCA, there is no further guidance on the recommended methodologies that
apply across industries and sectors outside the building and construction sector (ISO 21930). Due to the variety of products that
are recycled and the differences of their life cycles, several allocation methodologies have been developed and are currently applied
globally. There is no one approach that can be consistently recommended for all materials and products. ISO has standardized its
rules for allocation regarding Environmental Product Declarations (EPD) for Building and Construction Products in ISO 21930
and ISO 14025, the general EPD standard. This guide does not override these rules.
5.2 Appendix X1 to Appendix X7 provide examples of existing methodologies applied in different industries for different recycled
raw materials and products. These examples complement specific guidance and case studies for recycling in LCA as provided in
ISO/TR 14049 and go beyond the specific focus of ISO 14067 on carbon footprinting.
6. Summary of Methods
6.1 There are three primary frameworks for modeling end-of-life recycling in LCA, which are used most commonly by
practitioners globally. For all these frameworks, the guidelines for setting system boundaries should be in line with the ISO 14040
series standards. The selection of a modeling approach for secondary materials and recycling scenarios should reflect the goal and
scope of the LCA study.
6.1.1 The Recycled content/“cutoff” approach has been utilized in LCA for many years due to its simplicity and modeling ease.
The practitioner essentially places no beneficial environmental impact on the recycled content in the production phase of the life
cycle of the product being studied, and recycled materials collected at the end of life are sent to the next product system with no
environmental impact (beneficial or adverse). The end-of-life collection remains in product system A. The impacts arising from
the end-of-life collection processes/activities remain within and are attributed to the primary product system.
NOTE 1—This approach is mandated in ISO 21930.
6.1.2 The end-of-life recycling approach is based on the concept in ISO 14040 of system expansion. Essentially, the practitioner
expands the product system A boundary in order to give credit to the first life cycle for the beneficial impact of utilizing a material
that is recyclable in its initial use. The material for recycling is a beneficial impact given to product system A. The end-of life
approach covers end-of-life material for recycling. It potentially acknowledges recycling that has not yet taken place. The
end-of-life approach is often applied to open-loop product systems where materials are recycled and enter into subsequent product
systems. When this approach is used, it should not circumvent other relevant ISO 14000 series standards.
E3199 − 22a
FIG. 1 Material Flows in Common, Idealized Product System
6.1.3 The 50/50 (hybrid) approach uses a combined approach to distribute environmental impacts between product systems. It
takes the environmental impacts from end-of-life recycling and collection/sorting, and the environmental impact for the material
recycling is divided equally between product system A and product system B. Other splits (for example, 20/80 or 60/40) can also
be used and depend on the specific product system and use/recycling patterns.
6.1.4 There are also other approaches available including the waste valuation approach, which accounts for the value of the
material at the end of life (1).
6.1.5 More detailed guidance on the methodological aspects of the modeling of reuse, recycling, and recovery of energy are
provided by the International Reference Life Cycle Data System (ILCD) Handbook of the European Commission (2).
7. Synthesis
7.1 The following section demonstrates how the approaches described in Section 6 include recycling in LCAs and how impacts
associated with recycling are distributed over the product systems involved. The approaches for including recycling in LCAs are
applied to a generic production system. When changes in the inherent properties of materials occur, LCA practitioners should take
those into account in accordance with the guidance provided in the 2013 PEF Guidance document of the European Commission
(3). Product system A is described in Fig. 1. This product system consists of 60 % primary material and 40 % recycled material
inputs. Eighty percent of the material from the product system is collected at its end of life and recycled, 20 % is not recycled.
Half of the recycled material goes into the same product system A, whereas the other half goes into another product system B.
Environmental impacts can occur. There are different approaches on how to allocate/distribute the environmental impacts related
to the material recycling between the product systems A and B.
7.2 The recycled content approach (6.1.1 and Fig. 2) builds on the assumption that the secondary material input used in product
system A is free of environmental impacts except those that are related to required activities such as collection, sorting, processing,
and transport of the materials. In consequence, there are no environmental impacts from recycling the materials after use that can
be allocated to product system A. The recycled content approach instead acknowledges the recycling that has taken place.
7.3 The end-of-life approach (6.1.2) assumes that the secondary material input has the same environmental impacts as the primary
raw materials. It is therefore modeled as though 100 % of the input is from primary raw materials. The environmental impacts
associated with collection, sorting, transport, and processing are considered, as well as the environmental impacts related to the
replacement of primary raw materials with recycled materials. All impacts related to recycling are allocated to product system A,
as shown in Fig. 3. The end-of-life approach is often used for raw materials and product systems where recycling is significant
but does not necessarily take place in the same product system (“open-loop recycling”), which is different than “closed-loop
The boldface numbers in parentheses refer to a list of references at the end of this standard.
E3199 − 22a
FIG. 2 Recycled Content Approach
FIG. 3 End-of-life Approach
recycling” where recycling takes place in the same product system. For products with an extended lifetime, the end-of-life
approach acknowledges the potential environmental impacts from future recycling.
7.4 The 50/50 approach (6.1.3) describes a distribution of environmental impacts over two product systems A and B. The
environmental impacts resulting from recycling, preparatory activities (for example, sorting, collection), and the recycling
processes (processing) are distributed equally over both the product systems. It also is possible to adjust the environmental impacts
distribution (for example, 20/80 or 40/60) with appropriate justification. A 50/50 approach is shown in Fig. 4.
8. Appendix Preparation
8.1 This section provides the expected format and content for appendixes and the order in which each section should appear. All
appendix examples are expected to be consistent in structure and provide practitioners with concise information. They should not
exceed two pages in length.
8.2 Provide a description of the industry or the material discussed in the appendix.
8.3 Explain the implications for LCA studies including the standard recycling practices and relevant parameters influencing the
modeling approach, such as:
E3199 − 22a
FIG. 4 50/50 Approach
8.3.1 Supply and demand of the material.
8.3.2 Specific properties and use patterns.
8.3.3 Condition of material, whether a physical or chemical separation from other materials is required for recycling.
8.3.3.1 Feasibility and practicality of the separation process for recycling.
8.3.4 Typical product service life.
8.3.5 Potential changes in material properties during use and recycling.
8.3.6 Collection practices and the recycling process.
8.4 A simplified flow chart as illustrated in Section 7.
8.5 Some of the parameters mentioned above influence the choice of methodology. The approach for including recycling into LCA
should be stated and justified. The examples in 8.5.1 show how these parameters help to identify the appropriate approach.
8.5.1 Supply and Demand Examples:
8.5.1.1 The end-of life approach can promote increased collection and recycling efficiencies for materials when general demand
is steadily growing but the supply of recycled raw materials is more limited relative to that rate of growth due to a long product
life, as stated in Bergsma et al (4).
8.5.1.2 The recycled content approach is often applied for those products where supply and demand are in balance or where supply
exceeds demand.
8.5.2 Lifetime of Products Examples:
8.5.2.1 For products with an extended lifetime, the end-of-life approach acknowledges the potential beneficial environmental
impacts from future recycling.
8.5.2.2 The recycled content approach instead acknowledges the recycling that has taken place.
8.6 Third-party documentation or references such as Product Category Rules or journal articles should be provided when available
to support inclusion of the appendix and provide practitioners with additional background information.
E3199 − 22a
NOTE 2—All references that are not standards are listed at the end of the standard guide in accordance with ASTM format. Copies of the referenced
documents should be supplied with the appendix submission. The referenced document list is not considered part of the appendix length.
9. Keywords
9.1 50/50 (hybrid); allocation; cutoff approach; end-of-life; environmental impacts, life cycle assessment (LCA); recycled;
recycled content; recycling; sustainability
APPENDIXES
(Nonmandatory Information)
X1. RECYCLING OF COPPER:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X1.1 Copper Use
X1.1.1 Copper is used in many applications, including electricity generation and transmission, electrical and transport devices, and
construction materials. Copper use is increasing on a global scale, and recycling plays an important role in meeting this demand.
On average, copper contains 30 % recycled content globally (5).
X1.1.2 It is estimated that two-thirds of the 550 million tons of copper produced since 1900 are still in productive use (5). Of this
amount, approximately 70 % is used for electrical applications and 30 % for nonelectrical applications. Around 45 % is used in
power generation and transmission, 20 % in construction, 12.5 % in appliances and electronics, 12.5 % in transport, and 10 % in
other applications.
X1.1.3 A large percentage (approximately 50 %) of copper is used in a near pure form (>99.9 % copper content). This includes
copper products such as copper wire for electrical conductors and sheet for roofing applications. The remainder is mainly used in
the form of alloys, where it is mixed with other metals like zinc for brass and tin for bronze.
X1.2 Copper Recycling Pathways
X1.2.1 High copper content products can be recycled directly into new products by direct melting and reshaping, without the need
to be re-refined to copper cathode first. This is also valid for end-of-life materials for recycling made from alloys like brass or
bronze, when collected and sorted in mono-fraction. As a result, copper and its alloys belong to a group of metals where effective
recycling of scrap directly into new products is well established. In addition, even scrap with less than 1 % copper content can be
used as a replacement for primary copper sources (ore and concentrate). The potential for copper to be removed from
copper-containing scrap is not dependent on the concentration of copper in the mix (Fig. X1.1).
X1.3 Modeling Recycling of Copper in LCA
X1.3.1 The EOL materials for recycling from copper product systems are almost always fed back into the metal production cycle,
be it in the primary plants, secondary plants, or semi-fabrication, such as rod, tube, or wire. This is due both to its recyclability
as well as its value. The final product of copper recycling is identical to primary copper (for both the primary and secondary smelter
routes) when refined into purified copper. Similarly, copper will be similar in its properties to the original scrap material entering
the fabrication process for semi-fabrication. In addition, the copper scrap market has been historically not in oversupply, thus EOL
E3199 − 22a
FIG. X1.1 Recycling Paths of End-of-life Products Made from Copper Materials
materials for recycling from each product will substitute for primary material and not compete with other EOL materials for
recycling. This is likely to remain the case for many years to come, as demonstrated by copper demand projections linked to the
growing electric vehicle and electrification trends. Therefore, the end-of-life modeling approach is typically used for copper (6).
However, the practitioner should take into account market growth and scrap demand and ensure alignment with ISO 14040 series
standards when undertaking a study, in order to confirm this approach and ensure justification.
X1.3.2 As shown in Fig. X1.1, recycling is part of both the primary and secondary production of copper cathode. As losses are
dependent on technological production processes, a certain amount of primary material (for example, cathode) will still be
necessary in fabrication processes of products made from copper materials.
X2. RECYCLING OF FGD GYPSUM:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X2.1 FGD Gypsum Overview
X2.1.1 Flue gas desulfurization (FGD) gypsum (CaSO ·2H O) is used as a raw material for the production of gypsum panel
4 2
products in place of mined natural gypsum. As a co-product of electricity generation in coal-fired power plants, FGD gypsum is
produced in the SO scrubbing operations associated with stack emissions. FGD gypsum is substituted on an equal molar basis
with natural gypsum in gypsum panel production. For FGD gypsum to be used in the production of gypsum board, it should be
dewatered prior to shipment to the gypsum board manufacturing plant. FGD gypsum typically arrives at the gypsum board
manufacturing plant with a higher moisture content than natural gypsum requiring additional drying energy prior to calcination to
produce stucco suitable for producing gypsum board.
X2.2 Implications for Life Cycle Assessment
X2.2.1 LCA studies incorporating FGD gypsum use the recycled content approach applying no environmental impacts to the FGD
material. This approach is appropriate for a material that is essentially the byproduct of a pollution-control system and for which
significant portions of the material have no commercial use and are currently sent to landfill. The approach applied in the LCA
modeling of FGD gypsum in LCA is shown in Fig. X2.1. The modeling of FGD gypsum should include environmental impacts
of de-watering at the electrical facility and transportation of the FGD gypsum to the gypsum board or manufacturing site (7).
E3199 − 22a
FIG. X2.1 Simplified Scheme for Recycling of FGD Gypsum
X2.2.1.1 Some dewatering of the FGD gypsum occurs at the generation plant, and any energy associated with this should be taken
into account (8).
X3. RECYCLING OF GLASS:
METHODOLOGICAL APPROACHES IN LIFE CYCLE ASSESSMENT
X3.1 Background
X3.1.1 Glass is used in many applications all around the world, the most common being for packaging of food and beverages,
for fenestration, and for thermal insulation. Glass, which is not lost due to breakage and is in a form amenable to recycling, may
be recycled many times for the same composition. In many cases, compared to raw mineral materials, recycled glass requires less
energy to process into new glass products, yielding a net benefit in consumption of energy resources, lifetime of processing
equipment, and reduction in greenhouse gases (9-11).
X3.1.2 Recycled glass or “cullet” is primarily used by the packaging and fiberglass industries. The glass packaging manufacturing
in
...