SIST EN ISO 17225-5:2021

Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO 17225-5:2021)

This document determines the fuel quality classes and specifications of graded firewood. This document covers only firewood produced from the following raw materials (see ISO 17725‑1:2021, Table 1):
—    1.1.1 Whole trees without roots;
—    1.1.3 Stem wood;
—    1.1.4 Logging residues (thick branches, tops etc.);
—    1.2.1 Chemically untreated by-products and residues from wood processing industry.

Biogene Festbrennstoffe - Brennstoffspezifikationen und -klassen - Teil 5: Klassifizierung von Stückholz (ISO 17225-5:2021)

Dieses Dokument legt die qualitätsbezogenen Brennstoffklassen und  spezifikationen von klassifiziertem Stückholz fest. Dieses Dokument umfasst nur Stückholz, das aus folgenden Rohmaterialien hergestellt wurde (siehe ISO 17225-1:2021, Tabelle 1):
- 1.1.1 Vollbäume ohne Wurzeln;
- 1.1.3 Rundholz;
- 1.1.4 Waldrestholz (dicke Äste, Baumkronen usw.);
- 1.2.1 Chemisch unbehandelte Nebenprodukte und Rückstände aus Industrie-Restholz.

Biocombustibles solides - Classes et spécifications des combustibles - Partie 5: Classes de bois de chauffage (ISO 17225-5:2021)

Le présent document détermine les classes et spécifications de qualité du combustible pour le bois de chauffage. Le présent document couvre uniquement le bois de chauffage produit à partir des matières premières suivantes (voir ISO 17725-1:2021, Tableau 1):
—    1.1.1 Arbres entiers sans racines;
—    1.1.3 Grumes;
—    1.1.4 Rémanents forestiers (grosses branches, cimes, etc.);
—    1.2.1 Produits dérivés et sous-produits de l'industrie de transformation du bois sans traitement chimique.

Trdna biogoriva - Specifikacije goriv in razredi - 5. del: Razvrščena drva (ISO 17225-5:2021)

General Information

• Status: Published
• Public Enquiry End Date: 01-Nov-2020
• Publication Date: 07-Sep-2021
• ICS: 75.160.40 - Biofuels
• Technical Committee: AGO - Refuse derived fuel
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Aug-2021
• Due Date: 07-Oct-2021
• Completion Date: 08-Sep-2021
• Directive: 2014-01-4040 - Uredba o predelavi nenevarnih odpadkov v trdno gorivo in njegovi uporabi
• Directive: 2019-01-2272 - Uredba o emisiji snovi v zrak iz malih kurilnih naprav
• Ref Project: EN ISO 17225-5:2021 - Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO 17225-5:2021)

Relations

• Replaces: SIST EN ISO 17225-5:2014 - Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO 17225-5:2014)
• Effective Date: 01-Oct-2021
• Revised: oSIST prEN ISO 17225-5:2025 - Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO/DIS 17225-5:2025)
• Effective Date: 01-Jul-2025

Overview

EN ISO 17225-5:2021 - Solid biofuels: Graded firewood specifies fuel quality classes and product specifications for oven-ready, cut-and-split firewood used in household and small commercial appliances. Published as part of the ISO 17225 series and endorsed by CEN, this 2021 edition replaces EN ISO 17225-5:2014 and focuses on firewood produced from defined raw materials (whole trees without roots, stem wood, logging residues and chemically untreated wood by‑products).

Key topics and technical requirements

• Scope and raw materials: Applies to firewood from whole trees (no roots), stem wood, logging residues (thick branches, tops) and untreated wood-processing residues.
• Fuel classes: Defines graded firewood classes (notably A1, A2 suitable for stoves and fireplaces; B suitable for log wood boilers) to support consistent quality and trade.
• Physical dimensions: Specifies how to state length and maximum diameter of oven-ready logs (typical firewood length range 15–100 cm) and uses figure geometry for D (diameter) and L (length).
• Moisture and energy parameters: Covers declaration and measurement of moisture content (ar = as received; dry basis conventions) and energy density/ net calorific value. Annexes provide guidance on moisture conversion and energy density calculation.
• Sampling and analysis: Requires sampling and sample preparation per relevant methods (ISO 21945, ISO 14780) and moisture determination (ISO 18134 series). Producers may use measured values, calculated typical values, or laboratory analysis (simplified or reference methods).
• Chemical impurities: Routine reporting of ash, N, S, Cl and trace elements is generally not required for firewood from uncontaminated virgin material; analysis is recommended only if contamination is suspected.
• Product declaration: Quality information must be provided in declarations or labels; producers retain responsibility for accuracy whether using measured or typical values.

Applications and who uses it

• Producers and suppliers: For classifying, labelling and marketing graded firewood to end users.
• Traders and retailers: To ensure consistent product specifications across markets and simplify transactions.
• Appliance manufacturers and installers: To match fuel classes (A1/A2/B) with appliance requirements (stoves, fireplaces, boilers).
• Test laboratories and conformity bodies: For applying standardized sampling, moisture and calorific tests.
• Authorities and building operators: For procurement, permitting and reporting where classified firewood is required.

Related standards

• ISO 17225-1:2021 - General requirements for solid biofuels
• ISO 18134-1 / -2 - Moisture determination (oven dry methods)
• ISO 14780 - Sample preparation
• ISO 21945 - Simplified sampling for small-scale applications
• ISO 16559 - Terminology for solid biofuels

Keywords: EN ISO 17225-5:2021, graded firewood, solid biofuels, fuel specifications, firewood classes, moisture content, energy density, sampling, ISO 17225.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2021
Nadomešča:
SIST EN ISO 17225-5:2014
Trdna biogoriva - Specifikacije goriv in razredi - 5. del: Razvrščena drva (ISO 17225
-5:2021)
Solid biofuels - Fuel specifications and classes - Part 5: Graded firewood (ISO 17225-
5:2021)
Biogene Festbrennstoffe - Brennstoffspezifikationen und -klassen - Teil 5: Klassifizierung
von Stückholz (ISO 17225-5:2021)
Biocombustibles solides - Classes et spécifications des combustibles - Partie 5: Classes
de bois de chauffage (ISO 17225-5:2021)
Ta slovenski standard je istoveten z: EN ISO 17225-5:2021
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
July 2021
EUROPÄISCHE NORM
ICS 27.190; 75.160.40 Supersedes EN ISO 17225-5:2014
English Version
Solid biofuels - Fuel specifications and classes - Part 5:
Graded firewood (ISO 17225-5:2021)
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 17225-5:2021) (ISO 17225-5:2021)
This European Standard was approved by CEN on 12 June 2021.

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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17225-5:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 17225-5:2021) has been prepared by Technical Committee ISO/TC 238 "Solid
biofuels" in collaboration with Technical Committee CEN/TC 335 “Solid biofuels” 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 January 2022, and conflicting national standards shall
be withdrawn at the latest by January 2022.
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 17225-5:2014.
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 websites.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 17225-5:2021 has been approved by CEN as EN ISO 17225-5:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 17225-5
Second edition
2021-07
Solid biofuels — Fuel specifications
and classes —
Part 5:
Graded firewood
Biocombustibles solides — Classes et spécifications des
combustibles —
Partie 5: Classes de bois de chauffage
Reference number
ISO 17225-5:2021(E)
©
ISO 2021
ISO 17225-5:2021(E)
© ISO 2021
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 © ISO 2021 – All rights reserved

ISO 17225-5:2021(E)
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 firewood8 . 2
Annex A (informative) Comparison of moisture content as received and dry basis .7
Annex B (informative) Measurement of firewood . 9
Annex C (informative) Calculation of energy density.10
Bibliography .12
ISO 17225-5:2021(E)
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 238, Solid biofuels.
This second edition cancels and replaces the first edition (ISO 17225-5:2014), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Figure 1 and dimensions in Table 1 have been changed;
— Annex C 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 2021 – All rights reserved

ISO 17225-5:2021(E)
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 as well 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
buildings which require classified firewood quality.
The 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
[1] [2]
heaters and multifired sauna stoves, which are tested according to European standards EN 13229, EN 12815,
[3] [4] [5] [6] [7]
EN 12809, EN 13240, EN 15250 and EN 15821, and boilers systems tested according to EN 303–5 .
NOTE 2 For individual contracts ISO 17225-1 can be used.
Although this document may be obtained 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.
INTERNATIONAL STANDARD ISO 17225-5:2021(E)
Solid biofuels — Fuel specifications and classes —
Part 5:
Graded firewood
1 Scope
This document determines the fuel quality classes and specifications of graded firewood. This document
covers only firewood produced from the following raw materials (see ISO 17725-1:2021, Table 1):
— 1.1.1 Whole trees without roots;
— 1.1.3 Stem wood;
— 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 — Terminology, definitions and descriptions
ISO 17225-1:2021, Solid biofuels — Fuel specifications and classes — Part 1: General requirements
ISO 18134-1, Solid biofuels — Determination of moisture content — Oven dry method — Part 1: Total
moisture — Reference method
ISO 18134-2, Solid biofuels — Determination of moisture content — Oven dry method — Part 2: Total
moisture — 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 terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// 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.
ISO 17225-5:2021(E)
Note 2 to entry: Cut-offs from virgin wood can also be used as a firewood.
3.2
commercial application
facility that utilizes solid biofuel burning appliances or equipment that have similar fuel
...