SIST EN ISO 17225-5:2026

SLOVENSKI STANDARD
01-junij-2026
Nadomešča:
SIST EN ISO 17225-5:2021
Trdna biogoriva - Specifikacije goriv in razredi - 5. del: Razvrščena drva (ISO 17225
-5:2026)
Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO 17225-
5:2026)
Biogene Festbrennstoffe - Brennstoffspezifikationen und -klassen - Teil 5: Klassifizierung
von Stückholz (ISO 17225-5:2026)
Biocombustibles solides - Classes et spécifications des combustibles - Partie 5: Classes
de bois de chauffage (ISO 17225-5:2026)
Ta slovenski standard je istoveten z: EN ISO 17225-5:2026
ICS:
75.160.40 Biogoriva Biofuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 17225-5
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2026
EUROPÄISCHE NORM
ICS 27.190; 75.160.40 Supersedes EN ISO 17225-5:2021
English Version
Solid biofuels - Fuel specifications and classes - Part 5:
Graded firewood (ISO 17225-5:2026)
Biocombustibles solides - Classes et spécifications des Biogene Festbrennstoffe - Brennstoffspezifikationen
combustibles - Partie 5: Classes de bois de chauffage und -klassen - Teil 5: Klassifizierung von Stückholz
(ISO 17225-5:2026) (ISO 17225-5:2026)
This European Standard was approved by CEN on 4 April 2026.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17225-5:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 17225-5:2026) has been prepared by Technical Committee ISO/TC 238 "Solid
Biofuels and Pyrogenic Biocarbon" in collaboration with Technical Committee CEN/TC 335 “Solid
Biofuels and Pyrogenic Biocarbon” the secretariat of which is held by SIS.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2026, and conflicting national standards shall
be withdrawn at the latest by October 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 17225-5:2021.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 17225-5:2026 has been approved by CEN as EN ISO 17225-5:2026 without any
modification.
International
Standard
ISO 17225-5
Third edition
Solid biofuels — Fuel specifications
2026-04
and classes —
Part 5:
Graded firewood
Biocombustibles solides — Classes et spécifications des
combustibles —
Partie 5: Classes de bois de chauffage
Reference number
ISO 17225-5:2026(en) © ISO 2026

ISO 17225-5:2026(en)
© ISO 2026
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 17225-5:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 2
5 Specification of graded firewood . 2
Annex A (informative) Comparison of moisture content as received and dry basis. 6
Annex B (informative) Measurement of firewood . 8
Annex C (informative) Calculation of energy density . 9
Bibliography .11

iii
ISO 17225-5:2026(en)
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 238, Solid biofuels and Pyrogenic Biocarbon, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 335,
Solid Biofuels and Pyrogenic Biocarbon, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 17225-5:2021), which has been technically
revised.
The main changes are as follows:
— moisture in Table 1 has been changed.
A list of all parts in the ISO 17225 series can be found on the ISO website.
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
ISO 17225-5:2026(en)
Introduction
The objective of the ISO 17225 series is to provide unambiguous and clear classification principles for solid
biofuels, to serve as a tool to enable efficient trading of biofuels, to enable good understanding between
seller and buyer and as a tool for communication with equipment manufacturers. It also facilitates authority
permission, procedures and reporting.
This document supports the use of graded firewood for residential, small commercial and public building
applications which require classified firewood quality.
Residential, small commercial and public building appliances require higher quality fuel for the following
reasons:
— small-scale equipment does not usually have advanced controls and flue gas cleaning;
— appliances are not generally managed by professional heating engineers;
— appliances are often located in residential and populated districts.
NOTE 1 Firewood produced according to this document can be used in stoves, fireplaces, cookers, room heaters
[1] [2] [3]
and multifired sauna stoves, which are tested according to European standards EN 13229, EN 12815, EN 12809,
[4] [5] [6] [7] [8] [9] [10]
EN 13240, EN 15250, EN 15821, EN 16510–2–1, EN 16510–2–2, EN 16510–2–3, EN 16510–2–5, EN 16510–
[11] [12] [13] [14]
2–7, EN 16510–2–10, and boilers systems tested according to EN 303–5, EN 16510–2–4.
NOTE 2 For individual contracts, ISO 17225-1 can be used.
Although this document can be used separately, it requires a general understanding of the standards based
on and supporting ISO 17225-1. It is recommended to obtain and use ISO 17225-1 in conjunction with this
document.
v
International Standard ISO 17225-5:2026(en)
Solid biofuels — Fuel specifications and classes —
Part 5:
Graded firewood
1 Scope
This document specifies the fuel quality classes and specifications of graded firewood. This document
applies only to firewood produced from the following raw materials (see ISO 17225-1:2021, Table 1):
— 1.1.1 Whole trees without roots;
— 1.1.3 Stemwood;
— 1.1.4 Logging residues (thick branches, tops, etc.);
— 1.2.1 Chemically untreated by-products and residues from wood processing industry.
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 14780, Solid biofuels — Sample preparation
ISO 16559, Solid biofuels — Vocabulary
ISO 17225-1:2021, Solid biofuels — Fuel specifications and classes — Part 1: General requirements
ISO 18134-1, Solid biofuels — Determination of moisture content — Part 1: Reference method
ISO 18134-2, Solid biofuels — Determination of moisture content — Part 2: Simplified method
ISO 21945, Solid biofuels — Simplified sampling method for small scale applications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16559 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
firewood
cut and split oven-ready fuelwood used in household wood burning appliances like stoves, fireplaces and
central heating systems
Note 1 to entry: Firewood usually has a uniform length, typically in the range of 15 cm to 100 cm.
Note 2 to entry: Cut-offs from virgin wood can also be used as a firewood.

ISO 17225-5:2026(en)
3.2
commercial application
facility that utilizes solid biofuel burning appliances or equipment that have similar fuel requirements as
residential appliances
Note 1 to entry: Commercial applications are not to be confused with industrial applications, which
...