SIST EN ISO 21912:2021

Solid recovered fuels - Safe handling and storage of solid recovered fuels (ISO 21912:2021)

This document provides principles and requirements for safe handling, treatment and storage of solid recovered fuels (SRF), prepared from non-hazardous waste, to be used for energy purposes. This document covers process stages from point of acceptance of material to point of delivery of SRF.
This document excludes fuels that are included in the scope of ISO/TC 238 Solid biofuels and ISO/TC 28 Petroleum products and related products of synthetic or biological origin.
It uses a risk-based approach to determine what safety measures are to be considered.
Although unloading and loading of e.g. vessels, trains or trucks are included, the safety issues following the loading and transport itself are not.

Feste Sekundärbrennstoffe - Sicherer Umgang und Lagerung von festen Sekundärbrennstoffen (ISO 21912:2021)

Dieses Dokument enthält die Grundsätze für und Anforderungen an die sichere Handhabung, Behandlung und Lagerung von festen Sekundärbrennstoffen (SRF), die aus nicht gefährlichem Abfall hergestellt werden und für die energiewirtschaftliche Nutzung zu verwenden sind. Dieses Dokument umfasst Prozessabschnitte von der Stelle für die Annahme von Material bis zum Anlieferungsort von SRF.
Dieses Dokument schließt Brennstoffe aus, die in den Aufgabenbereich von ISO/TC 238 Solid biofuels und ISO/TC 28 Petroleum products and related products of synthetic or biological origin fallen.
Zur Bestimmung, welche Sicherheitsmaßnahmen in Betracht zu ziehen sind, wird ein risikobasierter Ansatz angewendet.
Zwar sind das Ent  und Beladen von z. B. Behältern, Zügen oder Lastkraftwagen enthalten, jedoch nicht die Sicherheitsaspekte nach dem Laden und der Transport selbst.

Combustibles solides de récupération - Sécurité de la mise en oeuvre et dus stockage de combustibles solides de récupération (ISO 21912:2021)

Le présent document fournit les principes et les exigences applicables à la sécurité de la mise en œuvre et du stockage de combustibles solides de récupération (CSR) préparés à partir de déchets non dangereux et destinés à être utilisés dans des applications énergétiques. Le présent document couvre les étapes du processus allant du poste de réception jusqu'au poste de livraison des CSR.
Le présent document exclut les combustibles couverts par l'ISO/TC 238, Combustibles solides et par l'ISO/TC 28, Produits pétroliers et produits connexes, combustibles et lubrifiants d'origine synthétique ou biologique.
Le présent document utilise une approche basée sur les risques pour déterminer les mesures de sécurité à prendre en compte.
Bien que le déchargement et le chargement des navires, des trains ou des camions (par exemple) soient inclus, les questions relatives à la sécurité suite au chargement et au transport en lui-même ne sont pas couvertes.

Trdna alternativna goriva - Varno ravnanje in skladiščenje trdnih goriv (ISO 21912:2021)

General Information

• Status: Published
• Public Enquiry End Date: 03-May-2020
• Publication Date: 15-Apr-2021
• ICS: 75.160.10 - Solid fuels
• Technical Committee: AGO - Refuse derived fuel
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 24-Mar-2021
• Due Date: 29-May-2021
• Completion Date: 16-Apr-2021
• Ref Project: EN ISO 21912:2021 - Solid recovered fuels - Safe handling and storage of solid recovered fuels (ISO 21912:2021)

Overview

EN ISO 21912:2021 - Solid recovered fuels (SRF): Safe handling and storage provides principles and requirements for the safe handling, treatment and storage of SRF prepared from non‑hazardous waste for energy use. The standard applies from the point of acceptance of material at an SRF facility up to the point of delivery of SRF. It uses a risk‑based approach to identify hazards and determine appropriate safety measures. Unloading and loading of transport units (vessels, trains, trucks) are included; however, safety issues that occur after transport (during transit or at the receiver) are excluded.

Key topics and technical requirements

EN ISO 21912:2021 organizes safety requirements across SRF production, handling and storage processes. Key technical topics include:

• Risk management framework - definition of scope, hazard identification, risk estimation, evaluation and risk control measures.
• Receiving and feeding - safe acceptance, feeding equipment and emergency feeding procedures.
• Size reduction - guidance on crushing, milling and shredding equipment and associated safety controls.
• Conveying systems - chain, screw, belt, bucket elevator and pneumatic conveying safety considerations.
• Storage solutions - design and safe practices for open piles, bales, silos, bunkers, boxes and hoppers; special guidance for mechanically densified SRF.
• Separation and screening - safe operation of screening, ferrous/non‑ferrous separation, density and optical sorting.
• Auxiliary systems - thermal drying, dust collection, moulding and cooling with emphasis on explosion and dust hazards.
• Fire protection and detection - prevention, detection systems, response measures, working‑environment controls and post‑fire actions.
• Operation, maintenance and documentation - housekeeping, maintenance procedures, contractor/visitor controls and emergency planning.
• Personnel safety - roles, training and occupational risk management.

Applications and users

This standard is practical for organizations and professionals involved in the SRF lifecycle and waste‑to‑energy operations, including:

• SRF producers and pre‑treatment facilities
• Waste‑to‑energy plants and cement kilns that accept SRF
• Plant designers, equipment manufacturers and integrators
• Health, safety and environmental managers, auditors and insurers
• Regulators and permitting authorities assessing SRF facility safety

Implementing EN ISO 21912 helps reduce fire, dust, mechanical and human‑factor risks, supports compliant facility design, improves operational reliability and facilitates safer SRF supply chains.

Related standards

• EN ISO 21912:2021 is the CEN‑endorsed adoption of ISO 21912:2021.
• The standard excludes fuels covered by ISO/TC 238 (solid biofuels) and ISO/TC 28 (petroleum and related products) - refer to those standards where applicable.
• For full compliance, apply local fire codes, occupational safety regulations and relevant CEN/ISO norms in conjunction with EN ISO 21912:2021.

Keywords: EN ISO 21912:2021, solid recovered fuels, SRF, safe handling, storage, risk‑based approach, fire protection, SRF production.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2021
Trdna alternativna goriva - Varno ravnanje in skladiščenje trdnih goriv (ISO
21912:2021)
Solid recovered fuels - Safe handling and storage of solid recovered fuels (ISO
21912:2021)
Feste Sekundärbrennstoffe - Sicherer Umgang und Lagerung von festen
Sekundärbrennstoffen (ISO 21912:2021)
Combustibles solides de récupération - Sécurité de la mise en oeuvre et dus stockage
de combustibles solides de récupération (ISO 21912:2021)
Ta slovenski standard je istoveten z: EN ISO 21912:2021
ICS:
75.160.10 Trda goriva Solid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21912
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 75.160.10
English Version
Solid recovered fuels - Safe handling and storage of solid
recovered fuels (ISO 21912:2021)
Combustibles solides de récupération - Sécurité de la Feste Sekundärbrennstoffe - Sicherer Umgang und
mise en oeuvre et dus stockage de combustibles solides Lagerung von festen Sekundärbrennstoffen (ISO
de récupération (ISO 21912:2021) 21912:2021)
This European Standard was approved by CEN on 15 February 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 21912:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21912:2021) has been prepared by Technical Committee ISO/TC 300 "Solid
recovered materials, including solid recovered fuels" in collaboration with Technical Committee
CEN/TC 343 “Solid Recovered Fuels” the secretariat of which is held by SFS.
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 September 2021, and conflicting national standards
shall be withdrawn at the latest by September 2021.
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.
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 21912:2021 has been approved by CEN as EN ISO 21912:2021 without any modification.

INTERNATIONAL ISO
STANDARD 21912
First edition
2021-02
Solid recovered fuels — Safe handling
and storage of solid recovered fuels
Combustibles solides de récupération — Sécurité de la mise en oeuvre
et dus stockage de combustibles solides de récupération
Reference number
ISO 21912:2021(E)
©
ISO 2021
ISO 21912:2021(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 21912:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Parts of the SRF process . 1
3.2 Risk management . 4
3.3 Operation and safety . 6
4 Introduction to the use of this document . 6
5 Risk management . 7
5.1 General . 7
5.2 Introduction to the risk management process . 9
5.2.1 Definition of scope . . 9
5.2.2 Hazard identification. 9
5.2.3 Risk estimation . 9
5.2.4 Risk evaluation .10
5.2.5 Risk reduction/control .10
6 SRF processes .11
6.1 SRF production process .11
6.2 Typical SRF receiving, storing and feeding at power plant or cement kiln .12
6.3 SRF production facilities including densifying .13
7 Safety considerations and requirements for SRF plant .14
7.1 Safety hazards .14
7.2 General requirements and recommendations for safe production and handling .16
7.3 General requirement for operation and maintenance .17
7.4 Documentation of operation procedures .17
7.5 Safety during operation .18
7.5.1 Operation .18
7.5.2 Housekeeping .19
7.5.3 Maintenance .19
7.5.4 Guidelines for visitors/contractors .20
7.6 Pre-planning of emergency operations .20
7.7 Personnel risks.21
8 Safety considerations and requirements for specific parts of the SRF production
and handling process .21
8.1 Receiving and feeding .21
8.1.1 General for all receiving and feeding solutions .21
8.1.2 Inputting the raw material into pre-treatment process .22
8.1.3 Feeders .23
8.1.4 Emergency feeding process .24
8.2 Crushing, milling and shredding .24
8.2.1 General for all crushers, mills and shredders .24
8.2.2 Pre-shredding .25
8.2.3 Main shredding .26
8.2.4 Fine shredding .27
8.3 Conveying .28
8.3.1 Chain conveyors.28
8.3.2 Screw conveyors . .30
8.3.3 Belt conveyors .30
8.3.4 Bucket elevators .31
8.3.5 Pneumatic conveying .32
ISO 21912:2021(E)
8.4 Storage solutions .33
8.4.1 General for all storage solutions .33
8.4.2 Storage of mechanically densified SRF .35
8.4.3 Open storage in piles .35
8.4.4 Bale storing .36
8.4.5 Silo storage .37
8.4.6 Bunker and box storage .38
8.4.7 Hoppers .39
8.5 Separation and screening .40
8.5.1 Screening .40
8.5.2 Ferrous metal separation .41
8.5.3 Non-ferrous metal separation .42
8.5.4 Density separation .42
8.5.5 Optical identification and sorting.43
8.6 Other systems .44
8.6.1 Thermal drying.44
8.6.2 Dust collecting system .44
8.6.3 Moulding and cooling .46
9 Fire protection .47
9.1 General requirements and recommendations for fire protection .47
9.2 Detection .48
9.3 During a fire .48
9.4 Working environment and safety during a fire .49
9.5 After a fire . .49
Bibliography .50
iv © ISO 2021 – All rights reserved

ISO 21912:2021(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 300, Solid recovered fuels.
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.
ISO 21912:2021(E)
Introduction
Modern society is based on production and consumption of an enormous variety of products, both for
industrial and private use. After its intended use, the product will be disposed as waste by the user
and will then enter the chain of waste management which includes a variety of handling, storage and
processing/recycling methods.
With production, handling, transportation and storage of SRF (Solid Recovered Fuels) there is always
a significant risk of fire and dust explosion. A fire or an explosion provides risks both for human health
and the environment and cause large economical losses. It is therefore important that operators
throughout the supply chain ensure that there is a developed strategy to prevent fires and to prevent
dust explosions, and if a fire should occur, a readiness to handle the fire effectively to reduce the
consequences.
Fires will, in addition to economic losses and effects on health and the environment, also have a negative
impact on the confidence in the SRF industry and difficulty to obtain insurance coverage might also
increase.
In facilities where dry combustible materials are handled such as in SRF facilities, there are several
risks present for fires and dust explosions. A typical cause for an ignition of the material is friction
heat or impact ignition sources generated within the processing chain. Such ignition sources can be
generated due to mechanical wear or break-down, metal pieces and stones, material overfeeding, etc.
Most mechanical machines contain moving parts that potentially could generate friction heat high
enough to ignite the material. Examples are shredders, conveyors, screening/separation machinery and
fans. Other sources causing ignitions are for example hot surfaces, electrical discharges, hot works and
self-ignition inside storages.
An ignition source can ignite the material being processed or dust accumulations inside and around the
machinery. It is important to take necessary measures for reducing the risk for ignitions. Accumulations
of combustible dust are intended to be avoided. However, dust can quickly accumulate to a stage where
it can become a significant fire load.
This document provides support, advice and guidance to facility owners, logistics providers, equipment
suppliers/manufacturers, consultants, authorities and insurance providers to assess and mitigate
different risks when producing, handling and storing SRF.
vi © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 21912:2021(E)
Solid recovered fuels — Safe handling and storage of solid
recovered fuels
1 Scope
This document provides principles and requirements for safe handling, treatment and storage of solid
recovered fuels (SRF), prepared from non-hazardous waste, to be used for energy purposes. This
document covers process stages from point of acceptance of material to point of delivery of SRF.
This document excludes fuels that are included in the scope of ISO/TC 238 Solid biofuels and ISO/TC 28
Petroleum products and related products of synthetic or biological origin.
It uses a risk-based approach to determine what safety measures are to be considered.
Although unloading and loading of e.g. vessels, trains or trucks are included, the safety issues following
the loading and transport itself are not.
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 12100, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 21637:2020, Solid recovered fuels — Terminology, definitions and descriptions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21637:2020 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 Parts of the SRF process
3.1.1
baling
process of producing a compressed material bundle or package secured by wires, hoops, cords or similar
3.1.2
belt conveyor
conveyor with an endless belt acting as a carrying and traction element
Note 1 to entry: There are several belt conveyor types, such as; troughed belt conveyor, deep troughed belt
conveyor, pipe belt conveyor, walled belt conveyor, flat belt conveyor and radial conveyor.
ISO 21912:2021(E)
3.1.3
belt feeder
shortened form of belt conveyor (3.1.2), normally running at slow speed, designed to extract or control
the rate of flow of bulk materials from hoppers
[SOURCE: EN 620:2002+A1: 2010, 3.2.4]
3.1.4
box
storage with two or three walls
3.1.5
bucket elevator
elevator for loose bulk materials with buckets as the carrying medium attached to a belt or chains as
the driving medium
Note 1 to entry: The bucket elevator consists of a strap forming belt, stretched vertically between a driving head
pulley and a pulley of foot. Buckets are attached to the strap and the whole is enclosed in a metal frame.
Note 2 to entry: The foot of the elevator is equipped with a chute in which the buckets are filled by shovelling and
a head shape suitable for evacuating grain by projection centrifugal.
[SOURCE: EN 618:2002+A1: 2010, 3.1.3 – modified: notes to entry were added]
3.1.6
bunker
storage which is closed on four sides and reachable from the top
3.1.7
chain conveyor
conveyor for loose bulk materials with a chain as the driving medium having attached flights or scraper
flights moving the material "en masse" in an enclosing trough
3.1.8
chain reclaimer
machine for loose bulk materials with a chain as driving medium having attached flights or scraper
flights moving the material in an open drop-in pit or drive over pit
3.1.9
conveyor system
number of linked conveyors with their ancillary equipment and control system
[SOURCE: EN 620:2002+A1: 2010, 3.1 – modified: "control system" was added]
3.1.10
crushing
mechanical reduction of particle size (3.3.4) by exerting mainly blunt deforming forces to a material
[SOURCE: ISO 21637:2020, 3.15]
3.1.11
density separation
separation of mixed materials by using density differences of the different fractions for classification
Note 1 to entry: With respect to SRF-production, most common application of density separation is wind
shifting applying airflow as conveying/transport medium. A process of separation by different densities of
particles and fluids.
3.1.12
dust collection system
system that collects free dust from the air in process systems
2 © ISO 2021 – All rights reserved

ISO 21912:2021(E)
3.1.13
electromagnetic separation of non-ferrous metals
separation of non-ferrous metals by inducing temporary magnetic forces
Note 1 to entry: This term is also known as eddy current separators.
[SOURCE: ISO 21637:2020, 3.26]
3.1.14
enclosed conveyor
conveyor which is enclosed to avoid contamination between the interior and the exterior environment
3.1.15
enclosed storage
storage that is enclosed to avoid contamination between the interior and the exterior environment
3.1.16
feeder
mechanical device for delivering material at a controlled rate
[SOURCE: ISO 1213-1:1993, 10.1.02]
3.1.17
ferrous metal separation
separation of ferrous metals by use of permanent magnetic forces
3.1.18
fine shredding
shredding (3.1.28) of materials to an average particle size of 20 mm - 50 mm
3.1.19
idler
mechanical element rotating on internal bearing and fitted to support the belt
Note 1 to entry: On belt conveyors (3.1.2), several idlers can be used. These are called e.g. troughing idler (which
supports the belt and maintains it in a troughed form), carrying idler, return idler.
3.1.20
main shredding
mechanical reduction of particle size of material via shredding (3.1.28) it to average particle size (3.3.4)
of 50 mm - 100 mm
3.1.21
manual separation
separation of material particles individually by hand or mechanical solution
3.1.22
optical recognition
recognition of material particles individually by optical sensors
[SOURCE: ISO 21637:2020, 3.50]
3.1.23
pneumatic conveying
method of transporting bulk materials by means of air through pipes or ducts
3.1.24
pre-shredding
mechanically reducing particle size of material by shredding (3.1.28) it to average particle size (3.3.4) of
100 mm – 300 mm
ISO 21912:2021(E)
3.1.25
screening
separation of larger particles from material flow, typically >150 mm
3.1.26
screw conveyor
conveyor for loose bulk materials with a trough or tube as the carrying medium, the material being
moved by the action of a rotating screw
3.1.27
screw reclaimer
mobile equipment located bellow a stockpile for continuously reclaiming bulk materials using a screw
as the carrying or conveying medium
[SOURCE: EN 618:2002+A1: 2010, 3.3.8]
3.1.28
shredding
mechanical reduction of particle size (3.3.4) by tearing, cutting or other means
[SOURCE: ISO 21637:2020, 3.73]
3.1.29
silo
part of a continuous handling system used to contain intended kind(s) of bulk material(s) during a
certain period of time
Note 1 to entry: The silo is usually charged from the top and discharged from one or more outlets at the bottom
or side.
[SOURCE: EN 617:2001+A1: 2010, 3.1 – modified: part of definition was added as a note to entry]
3.1.30
step feeder
feeder which uses friction to transfer material
Note 1 to entry: Walking floor is an example of a step feeder.
3.1.31
under-screen fraction
material fraction that goes through a screen
[SOURCE: ISO 21637:2020, 3.87]
3.2 Risk management
3.2.1
residual risk
risk (3.2.2) remaining after risk reduction measures have been implemented
[SOURCE: ISO/IEC Guide 51:2014, 3.8]
3.2.2
risk
combination of the probability of occurrence of harm and the severity of that harm
Note 1 to entry: The probability of occurrence includes the exposure to a hazardous situation, the occurrence of a
hazardous event and the possibility to avoid or limit the harm.
[SOURCE: ISO/IEC Guide 51:2014, 3.9]
4 © ISO 2021 – All rights reserved

ISO 21912:2021(E)
3.2.3
risk analysis
systematic use of available information to identify hazards and to estimate the risk (3.2.2)
[SOURCE: ISO/IEC Guide 51:2014, 3.10]
3.2.4
risk assessment
overall process comprising a risk analysis (3.2.3) and a risk evaluation (3.2.8)
[SOURCE: ISO/IEC Guide 51:2014, 3.11]
3.2.5
risk control
process of decision-making for managing and/or reducing risk (3.2.2); its implementation, enforcement
and re-evaluation from time to time, using the results of risk assessment as one input
3.2.6
risk criteria
terms of reference against which the significance of a risk (3.2.2) is evaluated
Note 1 to entry: Risk criteria are based on organizational objectives, and external and internal context.
Note 2 to entry: Risk criteria can be derived from standards, laws, policies and other requirements.
[SOURCE: ISO/IEC Guide 73:2009, 3.3.1.3]
3.2.7
risk estimation
process of assigning values to the probability of occurrence of events and their consequences
[SOURCE: ISO 13824:2020, 3.15]
3.2.8
risk evaluation
procedure based on the risk analysis (3.2.3) to determine whether tolerable risk (3.2.11) has been
exceeded
[SOURCE: ISO/IEC Guide 51:2014, 3.12]
3.2.9
risk management
coordinated activities to direct and control an organization with regard to risk (3.2.2)
[SOURCE: ISO/IEC Guide 73:2009, 2.1]
3.2.10
risk reduction measure
protective measure
action or means to eliminate hazards or reduce risks
[SOURCE: ISO/IEC Guide 51:2014, 3.13 – modified: example has been removed.]
3.2.11
tolerable risk
level of risk (3.2.2) that is accepted in a given context based on the current values of society
Note 1 to entry: For the purposes of this document, the terms "acceptable risk" and "tolerable risk" are considered
to be synonymous.
[SOURCE: ISO/IEC Guide 51:2014, 3.15]
ISO 21912:2021(E)
3.3 Operation and safety
3.3.1
hot particles
solid particles whose temperature that can be above minimum ignition temperature of flammable
gases or vapours and combustible dusts.
3.3.2
intended use
use of a machine in accordance with information for use provided in the instructions
[SOURCE: ISO 12100:2010, 3.23]
3.3.3
oversize particle
particle exceeding a specific particle size
Note 1 to entry: The definition of oversize particle is dependent on the application and determined between the
producer and user.
[SOURCE: ISO 21637:2020, 3.51]
3.3.4
particle size
size of the fuel particles as determined in a solid fuel
Note 1 to entry: Different methods of determination can give different results.
Note 2 to entry: See also particle size distribution (3.3.5) and over size particle (3.3.3).
3.3.5
particle size distribution
proportions of various particle sizes (3.3.4) in a solid fuel
[SOURCE: ISO 21637:2020, 3.53]
3.3.6
personal protective equipment
PPE
equipment that can include, but is not limited to, clothing, gloves, helmets, footwear and face protection
[SOURCE: ISO/TR 21808:2009, 2.1]
3.3.7
reasonably foreseeable misuse
use of a machine in a way not intended by the designer, but which can result from readily predictable
human behaviour
[SOURCE: ISO 12100:2010, 3.24]
3.3.8
reduced explosion pressure
resulting overpressure generated by an explosion in an enclosure after effective explosion venting or
explosion suppression
4 Introduction to the use of this document
Although risks in connection with the production, handling, transportation and storage of SRF are
recognized, factors affecting each risk are different depending on the material type, climate, processing
equipment, etc. This document does not intend to focus specifically on the separated risks for individual
components, but rather on how the components constitute parts in a system and for example, how
6 © ISO 2021 – All rights reserved

ISO 21912:2021(E)
hazards can be transferred. Therefore, broad and detailed instructions and recommendations on
requirements for design and construction of facility and processes and for operation and maintenance
of equipment are given in this document. This document is structured based on different parts in the
SRF production and handling process. Stakeholders such as regulators, producers, and consumers of
SRF are encouraged to develop regulations or guidelines, considering the local properties and situation
as well as this document. Users of this document are responsible for identifying local regulations.
5 Risk management
5.1 General
To improve the safety during production, handling and storage of SRF, both design and operation shall
be considered. Safety concerns anyone who is responsible or exposed to the hazards arising from the
activities within the premises, here limited to the scope of this document.
For identified hazards the following hierarchy shall be followed as a minimum:
1) Elimination
2) Substitution
3) Engineering controls
4) Administrative controls
5) Personal protective equipment (PPE)
The items above shall be addressed as early as during the design stage, as well as during operation and
maintenance.
For the operational management of occupational health and safety, the Plan-Do-Check-Act (PDCA)
model according to ISO 45001 should be used.
An important part of these processes, both during design and operation, is management of risk, which
includes several steps and sub-steps.
For this document the detailed steps which shall be followed and documented for the general risk
management are shown in Figure 1.
ISO 21912:2021(E)
Figure 1 — Risk management
The risk management process includes a risk analysis and a risk evaluation, which form the basis for
the risk assessment and what risk reduction/control measures are required for each specific plant.
The objects, issues and aspects to be considered and documented in the risk management process
are related to general design and construction and general operation and maintenance procedures
including preplanning of emergency operations.
For fire prevention and fire protection of machinery, ISO 19353 should be used, when applicable.
Further specific issues to consider are also provided for receiving and feeding (8.1.1); crushing, milling
and shredding (8.2); conveying (8.3); storage solutions (8.4); separation and screening (8.5); and other
systems (8.6).
The documentation shall describe and justify the measures taken, as well as include aspects not
considered applicable or relevant.
The person responsible for the risk management process shall have the necessary levels of competence
to undertake a fire and explosion risk assessment; the level of competency required should be
commensurate with the complexity of the facility to be assessed, i.e.:
a) A good understanding of SRF and the equipment and processes used for the production and along
the supply chain of SRF
b) A good understanding of fire related aspects of building control and function
c) Appropriate knowledge of national fire/explosion and safety legislation and the requirements of
other enforcing bodies and stakeholders (i.e. insurers)
d) Appropriately trained and/or experienced in fire/explosion safety and fire protection issues
8 © ISO 2021 – All rights reserved

ISO 21912:2021(E)
e) Knowledge of relevant national and local codes and experience of application
5.2 Introduction to the risk management process
Management of risks include several steps and sub-steps as shown in Figure 2. In 5.2.1 to 5.2.5, the
different parts of risk management are defined and described.
5.2.1 Definition of scope
When performing a risk analysis, the scope shall be defined, i.e. the system that is to be included in the
analysis. This includes definition of the boundary of the system and to identify user, intended use and
reasonably foreseeable misuse. Assumptions and limitations for the analysis should also be defined.
Technical, environmental, organisational and other aspects relevant for the problem/system should be
included.
5.2.2 Hazard identification
Hazard identification involves systematic review of the system under study to identify the type of
inherent hazards that are present together with the ways in which they could be realized. Different
hazards and sources of risks shall be identified and the type of hazard they pose analysed. Hazard
identification methods fall mainly into three categories:
1) Comparative methods (e.g. checklists, hazard indices and reviews of historical data)
2) Fundamental methods, that are structured to stimulate a group of people to apply foresight in
conjunction with their knowledge to the task of identifying hazards (e.g. HAZOP studies, ISO 12100
and FMEA)
3) Inductive reasoning techniques (e.g. event tree logic diagrams)
The significance of the sources of risks shall be analysed by an initial evaluation, based on a consequence
analysis. The aim of this analysis is to decide whether:
a) Actions should be taken to eliminate or reduce the hazard
b) The analysis can be terminated due to the insignificance of hazard
c) The analysis should be continued with a risk estimation
There are many factors influencing the risk management, e.g. the storage capacity, annual SRF turnover
and complexity of on-site handling and to consider all the variables that might be valid for a facility.
5.2.3 Risk estimation
Risk estimation should examine the initiating events or circumstances, the sequence of events that
are of concern, any mitigating features and the nature and frequency of the possible deleterious
consequences of the individual hazards to produce a measure of the level of the risk being analysed.
The measures could address human, property or environmental risks and should include an indication
of the uncertainty associated with the estimates. The risk estimation process can be described by the
following steps:
a) Frequency analysis used to estimate the likelihood of each undesired event identified during the
hazard identification stage. To estimate event frequencies three different approaches are commonly
used: relevant historical data, analytical or simulation techniques and expert judgement
b) Consequence analysis is used to estimate the likely impacts should the undesired event occur
c) Risk calculations where risk should be expressed in the most suitable term, e.g.: individual risk,
predicted frequency of mortality, frequency versus consequence plots (F-N curves), the statistically
ISO 21912:2021(E)
expected loss rate in terms of casualties, economic loss or environmental damage, the distribution
of the risk of a specific damage level
5.2.4 Risk evaluation
When risk analysis has been completed, risk evaluation shall be carried out in accordance with
ISO 12100, or a similar nationally or internationally standardised methodology included in the
operational management of occupational health and safety of the organization, to determine if risk
reduction is required. If risk reduction is required, then appropriate measures shall be selected and
applied.
5.2.5 Risk reduction/control
Based on the risk evaluation, measures shall be taken to achieve an adequate risk reduction. Where
hazard or hazardous situations with multiple risks have been identified, care should be taken to prevent
risk reduction measures chosen to reduce one risk from resulting in another intolerable risk. Risk
reduction can be divided in measures taken during design and during the use phase, respectively. The
measures shall in turn be divided into different st
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