ISO 20423:2025

Carbon footprint for seafood — Product category rules (CFP-PCR) for macroalgae

This document specifies requirements for calculating the carbon footprint specific to farmed macroalgae product category rules (CFP–PCR). This methodology builds on the requirements of International Standards for life cycle assessment (LCA) and products’ carbon footprints. This document is applicable to the calculation and communication of farmed macroalgae products’ carbon footprints from seedling production to the consumption of macroalgae products. It is applicable to the carbon footprints of products from aquaculture value chains. This document used alone does not apply to specifying a product’s overall environmental or sustainability characteristics.

Empreinte carbone des fruits de mer — Règles de définition des catégories de produit (CFP–PCR) pour les macroalgues

General Information

• Status: Published
• Publication Date: 16-Jun-2025
• ICS: 67.120.30 - Fish and fishery products
• Technical Committee: ISO/TC 234 - Fisheries and aquaculture
• Drafting Committee: ISO/TC 234 - Fisheries and aquaculture
• Current Stage: 6060 - International Standard published
• Start Date: 17-Jun-2025
• Due Date: 27-Mar-2026
• Completion Date: 17-Jun-2025

Standards Content (Sample)

International
Standard
ISO 20423
First edition
Carbon footprint for seafood —
2025-06
Product category rules (CFP-PCR)
for macroalgae
Empreinte carbone des fruits de mer — Règles de définition des
catégories de produit (CFP–PCR) pour les macroalgues
Reference number
© ISO 2025
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 .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Quantification of the carbon footprint of a product .1
3.2 Products, product systems and processes .2
3.3 Data and data quality .5
3.4 Greenhouse gases . .5
3.5 Waste, storage and transport .5
4 Calculation and communication requirements . 6
5 Methodological requirements . 6
5.1 General .6
5.2 Functional unit or declared unit .6
5.3 Principles of data and methodological reporting .7
5.4 System boundaries . .7
5.4.1 General .7
5.4.2 The cut-off criterion: General rule for what can be excluded from the carbon
footprint .8
5.4.3 General processes that can be excluded .9
5.4.4 System boundaries for waste .9
5.4.5 Use of recycled materials .9
5.4.6 Capital investments .9
5.4.7 System boundaries for farming .9
5.4.8 System boundaries for harvesting .10
5.4.9 System boundaries for processing .11
5.4.10 System boundaries for distribution to dealers . 12
5.4.11 System boundaries for final consumption . 13
5.5 Data requirements . 13
5.5.1 General . 13
5.5.2 Rules for data sampling .14
5.5.3 Data on electricity .14
5.5.4 Data on fuel .14
5.5.5 Geographical delimitation .14
5.5.6 Time delimitation .14
5.5.7 Validation of data .14
5.5.8 Transport calculation rules .14
5.6 Allocation . 15
5.7 Impact assessment . 15
5.8 Interpretation . 15
5.9 Fossil and biogenic carbon .16
5.10 Communication of carbon footprints for macroalgae .16
5.10.1 General .16
5.10.2 Details about the producer .16
Annex A (informative) Example of data collection in the calculation of the carbon footprint of
macroalgae products . . 17
Annex B (informative) Additional information for farming nutrients accounting through
elemental mass balances of macroalgae .18
Annex C (informative) Example of mass allocation for kelp co-product processing .21
Annex D (informative) Example of LCA dried Porphyra yezoensis value-chain modelling .22
Annex E (informative) Example of LCA ground seaweed value-chain modelling .24

iii
Bibliography .25

iv
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 234, Fisheries and aquaculture.
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.

v
Introduction
With the increasingly serious global climate problem, the low-carbon revolution of globalization is rising,
and carbon peaking and carbon neutrality have become important goals of global low-carbon development.
Countries all over the world are actively carrying out double carbon research to achieve the goal of carbon
neutrality as soon as possible.
As an important participant in the ocean carbon cycle, algae can synthesize organic matter through
photosynthesis and release oxygen to achieve carbon sequestration, so it is of great significance to study its
carbon footprint.
This document contains product category rules for the calculation and communication of the carbon
footprint of macroalgae products, providing a convenient and feasible carbon footprint evaluation basis for
the macroalgae farming industry.
This document sets out rules for the calculation and communication of farmed macroalgae products, which
are applicable to the evaluation of the carbon footprint of the entire value chain of farmed macroalgae. The
methodology is based on the requirements of the life cycle assessment and International Standards for
the carbon footprint of products. The overarching aim of the document is to provide a basis for reliable
and accurate information about the climate impact of the product. It is a pre-conditi
...