ISO 4370:2022

Environmental life cycle assessment and recycling of ductile iron pipes for water applications

This document specifies the evaluation method of the environmental life cycle assessment (E-LCA) of ductile iron (DI) pipes used for water applications as specified in ISO 2531 and ISO 16631. This evaluation method, applicable to ductile iron pipe products, is based on concepts and methods developed in ISO 14040 and its application guidelines in ISO 14044.

Evaluation du cycle de vie environnemental et recyclage des tuyaux en fonte ductile utilisés pour l'eau

General Information

• Status: Published
• Publication Date: 30-Jun-2022
• ICS: 23.040.10 - Iron and steel pipes
• Technical Committee: ISO/TC 5/SC 2 - Cast iron pipes, fittings and their joints
• Drafting Committee: ISO/TC 5/SC 2/WG 22 - Life cycle analysis and recycling
• Current Stage: 6060 - International Standard published
• Start Date: 01-Jul-2022
• Due Date: 16-Jul-2023
• Completion Date: 01-Jul-2022

Overview

ISO 4370:2022 - Environmental life cycle assessment and recycling of ductile iron pipes for water applications - specifies a standardized method to evaluate the environmental life cycle assessment (E‑LCA) of ductile iron (DI) pipes used in water systems (per ISO 2531 and ISO 16631). The method is based on the life cycle assessment framework of ISO 14040 and the requirements of ISO 14044, and focuses primarily on quantifying CO2‑equivalent (CO2e) emissions across all life cycle stages and on the role of recycling in reducing environmental impact.

Key technical topics and requirements

• Scope and applicability
  • Applies to ductile iron pipe products for potable water and related water applications as defined in ISO 2531/16631.
• E‑LCA fundamentals
  • Defines E‑LCA terms (functional unit, service life, reference service life - RSL, in‑use conditions) consistent with ISO lifecycle terminology.
  • Emphasizes quantifying environmental impacts, with a primary focus on CO2 emissions but noting applicability to other impact categories (e.g., eutrophication, acidification, resource depletion).
• Life cycle stages and CO2 accounting
  • Provides methods and formulas to calculate total CO2e across: acquisition (manufacture and construction), operation (e.g., pumping energy), maintenance (leakage, repairs) and end‑of‑life.
  • Includes case calculations for different service‑life scenarios and time horizons.
• Key drivers for impact reduction
  • Durability and reference service life (RSL), leakage rates, conveyance capacity, optimal wall thickness, mechanical properties, installation methods, and recyclability.
• Recycling and annexes
  • Annex A: calculation methodology for CO2 accounting with provision for scrap recycling in DI pipe production.
  • Annex B: CO2 accounting for pump operation.
  • Annex C: scenario analyses comparing different ductile iron pipeline options.

Practical applications - who uses this standard

• Water utilities and asset managers - for sustainable procurement, lifecycle planning and infrastructure replacement strategies.
• Pipeline designers and civil engineers - to compare design options using consistent E‑LCA methods (e.g., sizing, material selection, installation methods).
• Ductile iron pipe manufacturers - to quantify cradle‑to‑gate impacts, optimize manufacturing and recycling loops, and prepare Environmental Product Declarations (EPDs).
• Environmental consultants and regulators - to support policy, ecolabelling, environmental claims and comparative lifecycle studies.
• Procurement and sustainability teams - for strategic decision‑making, tender specifications and demonstrating reduced CO2 footprints.

Related standards

• ISO 2531 - Ductile iron pipes, fittings, accessories and their joints for water applications
• ISO 16631 - (referenced in scope for specific DI pipe uses)
• ISO 14040 / ISO 14044 - LCA principles and requirements
• ISO 15686‑1 - Reference service life concepts (RSL)

ISO 4370:2022 provides a practical, traceable framework for assessing and reducing the climate impact of ductile iron water pipelines through standardized E‑LCA methods and explicit treatment of recycling.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4370
First edition
2022-07
Environmental life cycle assessment
and recycling of ductile iron pipes for
water applications
Evaluation du cycle de vie environnemental et recyclage des tuyaux
en fonte ductile utilisés pour l'eau
Reference number
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basic concept of environmental life cycle assessment (E-LCA). 2
4.1 General . 2
4.2 Definition of environmental life cycle assessment (E-LCA) . 2
4.3 Calculation method of CO emissions. 3
4.4 Other impacts . 3
5 Breakdown of CO emissions . 4
5.1 CO emissions at acquisition stage . 4
5.2 CO emissions at operation stage . 4
5.3 CO emissions at maintenance stage . 5
5.4 CO emissions at end-of-life stage . 5
6 Key drivers for environmental impact reduction . 5
6.1 Durability . 5
6.1.1 Reference service life (RSL) of DI pipes . 5
6.1.2 In-use conditions . 6
6.1.3 Service safety conditions . 6
6.2 Leakage incident . 6
6.3 Conveyance capacity . 7
6.3.1 General . 7
6.3.2 Functional unit of DI pipes . 7
6.4 Optimum pipe wall thickness . 7
6.5 Mechanical properties . 7
6.6 Various pipe installation methods . 7
6.7 Recyclability . 8
7 Recycling . 8
Annex A (informative) Calculation methodology for CO emissions with provision for scrap
recycling in ductile iron pipe production.10
Annex B (informative) CO emissions with pump operation .12
Annex C (informative) Scenario of CO emissions with different ductile iron pipelines .15
Bibliography .16
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings,
Subcommittee SC 2, Cast iron pipes, fittings and their joints.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
The growing awareness of the importance of environmental protection, and the possible impacts
associated with products, both manufactured and consumed, has increased interest in the development
of methods to better understand and address these impacts. One of the techniques developed for this
purpose is the environmental life cycle assessment (E-LCA).
E-LCA can assist in
— identifying opportunities to improve the environmental performance of products at various points
in their life cycle;
— informing decision-makers in industry, government or non-governmental organizations (e.g. for the
purpose of strategic planning, priority setting, product or process design or redesign);
— the selection of relevant indicators of environmental performance, including measurement
techniques;
— marketing (e.g. implementing an ecolabelling scheme, making an environmental claim, or producing
an environmental product declaration).
The concept of reference service life (RSL) is defined according to ISO 15686-1:2011 which identifies
and establishes general principles for service- life planning and a systematic framework for undertaking
service- life planning of a planned construction work throughout its life cycle.
This document is mainly focused on CO emissions. The methods can be applied also to other
environmental factors, e.g. other greenhouse gases emissions, natural resources consumption, water
consumption.
v
INTERNATIONAL STANDARD ISO 4370:2022(E)
Environmental life cycle assessment and recycling of
ductile iron pipes for water applications
1 Scope
This document specifies the evaluation method of the environmental life cycle assessment (E-LCA)
of ductile iron (DI) pipes used for water applications as specified in ISO 2531 and ISO 16631. This
evaluation method, applicable to ductile iron pipe products, is based on concepts and methods
developed in ISO 14040 and its application guidelines in ISO 14044.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2531:2009, Ductile iron pipes, fittings, accessories and their joints for water applications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2531 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
environmental life cycle assessment
E-LCA
compilation and evaluation of the inputs, outputs and the potential environmental impacts (3.2) of a
product system
Note 1 to entry: Environmental life cycle assessment and environmental life cycle analysis are synonymous.
[SOURCE: ISO 14040:2006, 3.2, modified — The term has been changed from "life cycle assessment" to
"environmental life cycle assessment"; "throughout its life cycle" at the end of the definition has been
removed. Note 1 to entry has been added.]
3.2
environmental impact
change to the environment, whether adverse or beneficial, wholly or partially resulting from an
organization's activities, products or services
[SOURCE: ISO 14001:2015, 3.2.4, modified — "environmental aspects" has been replaced by "activities,
products or services".]
3.3
CO emissions
release of equivalent CO as greenhouse gases into the atmosphere over a specified area and period of
time
3.4
service life
period of time after installation during which a facility or its component parts meet or exceed the
performance requirements
[SOURCE: ISO 15686-1:2011, 3.25]
3.5
functional unit
quantified performance of a product system for use as a reference unit
[SOURCE: ISO 14040:2006, 3.20]
3.6
reference service life
RSL
service life (3.4) of a product, component, assembly or pipeline which is known to be expected under a
particular set, i.e. a reference set, of in-use conditions (3.7) and which can form the basis for estimating
the service life under other in-use conditions
[SOURCE: ISO 15686-1:2011, 3.22, modified — "system" has been replaced by "pipeline".]
3.7
in-use condition
any circumstance that can impact on the performance of a pipeline, or a part thereof, under normal use
[SOURCE: ISO 15686-1:2011, 3.10, modified — "a building or a constructed asset" has been replaced by
"a pipeline".]
4 Basic concept of environmental life cycle assessment (E-LCA)
4.1 General
Studies on environmental impacts are important for utility decision-makers as they seek to balance
budget concerns over immediate and long-term needs across acquisition, operation and maintenance,
and planned end-of-life. For authorities and engineers designing pipeline systems, E-LCA serves as a tool
to study various scenarios to determine the right solution for site-specific conditions and community
values, as well as provide the necessary data to support those decisions.
4.2 Definition of environmental life cycle assessment (E-LCA)
E-LCA is a technique used to assess environmental impacts through all the stages of product and
service life. The environmental impact associated with the consumption of natural resources or energy
and waste disposal can be quantitatively estimated as the amount of CO emissions.
Total CO emissions is calculated using Formula (1) as a total amount of CO emissions through all life
2 2
cycle stages such as acquisition stage, operation stage, maintenance stage and end-of-life stage.
EE=+ EE++ E (1)
TA OM E
where
E is the total CO emissions through all life cycle stages;
T 2
E is the CO emissions at acquisition stage;
A 2
E is the CO emissions at operation stage;
O 2
E is the CO emissions at maintenance stage;
M 2
E is the CO emissions at end-of-life stage.
E 2
4.3 Calculation method of CO emissions
The total amount of CO emissions is calculated using Formulae (2) to (4) by totalizing all the CO
2 2
emissions in a period of analysis.
Case 1: t < t
n m
t
n
EE=+ ()EE+ (2)
TA OM,,tt
∑
t=1
Case 2: t = t
n m
t
n
EE=+ ()EE++E (3)
TA OM,,tt E
∑
t=1
Case 3: t < t < 2 × t
m n m
t
n
EE=×2 ++()EE +E (4)
TA OM,,tt E
∑
t=1
where
E is the total CO emissions;
T 2
t is the time in years;
t is the period of analysis;
n
t is the service life;
m
E is the CO emissions at acquisition stage;
A 2
th
E is the CO emissions at operation stage in the t year;
O,t 2
th
E is the CO emissions at maintenance stage in the t year;
M,t 2
E is the CO emissions at end-of-life stage.
E 2
4.4 Other impacts
Environmental impacts can also be evaluated in other categories which are listed below.
— impact on the environment:
— climate change;
— air, water and soil pollution;
— ozone depletion;
— eutrophication;
— acidification;
— reduction of biological diversity;
— impact on human health:
— hazardous substance emissions;
— smog formation;
— impact on natural resource consumption:
— depletion of resources.
5 Breakdown of CO emissions
5.1 CO emissions at acquisition stage
CO emissions at acquisition stage is calculated using Formula (5) as a total of CO emissions with pipe
2 2
manufacture, construction material production, construction machine operation, transportation and
regeneration treatment of excavated soil.
E =+EEE++ EE+ (5)
AAPACAOATAR
where
E is the CO emissions at acquisition stage;
A 2
E is the CO emissions with pipe manufacture (e.g. raw material procurement, transportation
AP 2
to the factory, manufacturing);
E is the CO emissions with construction material production (e.g. asphalt pavement materials,
AC 2
road bedding materials, sand);
E is the CO emissions with construction machine operation for pipe laying work (e.g. installation
AO 2
of pipes and valves by crane, crush and loading of existing pavement by backhoe, excavation
and loading of soil by backhoe, backfilling by backhoe, compaction by tamper, road bedding by
tamper or vibratory roller, asphalt paving work by vibratory roller or vibratory compactor);
E is the CO emissions with transportation of construction materials, construction machines,
AT 2
excavated soil, ground-improved soil and construction waste;
E is the CO emissions with regeneration treatment of excavated soil.
AR 2
NOTE The calculation methodology for CO emissions with provision for scrap recycling in ductile iron pipe
production is given in Annex A.
5.2 CO emissions at operation stage
Annual CO emissions at operation stage is calculated using Formula (6) as a total of CO emissions with
2 2
pump operation. Calculation method of CO emissions with pump operation is given in Annex B.
EE= (6)
OO,,ttP
where
th
E is the CO emissions at operation stage in the t year;
O,t 2
th
E is the CO emissions with pump operation in the t year.
OP,t 2
Annex C gives information about the general relative high proportion of CO emissions at operation
stage.
5.3 CO emissions at maintenance stage
Annual CO emissions at maintenance stage is calculated using Formula (7) as a total of CO emissions
2 2
due to leakage, during machine operation for maintenance, production of restoration materials and
during machine operation for restoration.
EE=+EE++E (7)
MM,,ttLMMM,,ttPMR,t
where
th
E is the CO emissions at maintenance stage in the t year;
M,t 2
th
E is the CO emissions with leakage in the t year;
ML,t 2
E is the CO emissions with machine operation for maintenance (e.g. inspection, drainage,
MM,t 2
th
washing) in the t year;
th
E is the CO emissions with production of restoration materials in the t year;
MP,t 2
th
E is the CO emissions with machine operation for restoration work in the t year.
MR,t 2
5.4 CO emissions at end-of-life stage
CO emissions at end-of-life stage is cal
...