prEN 1755

Safety of industrial trucks - Operation in potentially explosive atmospheres - Use in flammable gas, vapour, mist and dust

This standard applied to the potentially explosive atmospheres in industrial trucks,  including self- propelled and  pedestrian controlled manual and semi-manual industrial trucks.

Flurförderzeuge - Sicherheitsanforderungen und Verifizierung - Zusätzliche Anforderungen für den Einsatz in explosionsgefährdeten Bereichen

Dieses Dokument gilt für motorkraftbetriebene und mitgängerbetriebene, manuelle und halbmanuelle Flurförderzeuge, wie in ISO 5053-1:2020 festgelegt, einschließlich deren Lastaufnahmemittel und Anbaugeräte (im Folgenden als Flurförderzeuge bezeichnet) für die bestimmungsgemäße Anwendung in explosionsgefährdeten Bereichen.
ANMERKUNG 1   Auf dem Lastenträger oder an den Gabelzinken angebrachte Anbaugeräte, die durch den Benutzer abnehmbar sind, gelten nicht als Teil des Flurförderzeugs.
Dieses Dokument legt ergänzende technische Anforderungen zur Verhinderung der Zündung einer explosionsfähigen Atmosphäre aus brennbaren Gasen, Dämpfen, Nebeln oder Stäuben durch Flurförderzeuge der Gerätegruppe II und Gerätekategorie 2G, 3G, 2D oder 3D fest.
ANMERKUNG 2   Der Zusammenhang zwischen einer Gerätekategorie (im Folgenden als Kategorie bezeichnet) und der zugehörigen Zone (Einteilung von explosionsgefährdeten Bereichen) ist im informativen Anhang B dargestellt.
Dieses Dokument ist nicht anwendbar auf:
-   Flurförderzeuge der Gerätegruppe I;
-   Flurförderzeuge der Gerätegruppe II, Gerätekategorie 1;
-   Flurförderzeuge, die zur Anwendung in explosionsgefährdeten Bereichen mit hybriden Gemischen vorgesehen sind;
-   Schutzsysteme.
Dieses Dokument gilt wegen der besonderen Eigenschaften dieser Gase nicht für Flurförderzeuge, die für den Einsatz in explosionsgefährdeten Bereichen mit Schwefelkohlenstoff (CS2), Kohlenmonoxid (CO) und/oder Ethylenoxid (C2H4O) vorgesehen sind.
Die technischen Anforderungen im Zusammenhang mit Lithium-Ionen-Batterien und Brennstoffzellen als Energiequellen sind aufgrund ihrer spezifischen Gefährdungen nicht in diesem Dokument angegeben.

Sécurité des chariots de manutention - Fonctionnement en atmosphères explosibles - Utilisation dans des atmosphères inflammables dues à la présence de gaz, de vapeurs, brouillards ou poussière inflammables

Le présent document s’applique aux chariots automoteurs et aux chariots à conducteur à propulsion manuelle et semi-manuelle, tels que définis dans l’ISO 5053-1:2020, y compris leurs dispositifs de manutention des charges et accessoires (désignés ci-après par « chariots ») destinés à être utilisés en atmosphères explosibles.
NOTE 1   Les accessoires démontables par l’utilisateur qui sont installés sur le porteur de charge ou sur les bras de fourche ne sont pas considérés comme faisant partie intégrante du chariot.
Le présent document spécifie les prescriptions techniques supplémentaires relatives à la prévention de l’inflammation d’une atmosphère explosive de gaz, vapeurs, brouillards ou poussières inflammables, dus aux chariots de manutention du groupe d’appareil II et de la catégorie d’appareil 2G, 3G, 2D ou 3D.
NOTE 2   La relation entre une catégorie d’appareil (désignée ci-après par « catégorie ») et la zone correspondante (classification de zone) est illustrée à l’Annexe B (informative).
Le présent document n'est pas applicable :
-   aux chariots du groupe d’appareil I ;
-   aux chariots du groupe d’appareil II, catégorie d’appareil 1 ;
-   aux chariots destinés à être utilisés en atmosphères explosibles constituées de mélanges hybrides ;
-   aux systèmes de protection.
Le présent document ne s’applique pas aux chariots destinés à être utilisés en atmosphères explosibles contenant du sulfure de carbone (CS2), du monoxyde de carbone (CO) et/ou de l’oxyde d’éthylène (C2H4O), en raison des propriétés spécifiques de ces gaz.
Les prescription techniques relatives aux batteries lithium-ion et aux piles à combustibles en tant que sources d’énergie ne sont pas données dans le présent document en raison de leurs phénomènes dangereux spécifiques.

Vozila za talni transport - Varnostne zahteve in preverjanje - Dodatne zahteve za delovanje v potencialno eksplozivnih atmosferah

General Information

• Status: Not Published
• Publication Date: 05-Sep-2023
• ICS: 53.060 - Industrial trucks
• Technical Committee: CEN/TC 150 - Industrial trucks - Safety
• Drafting Committee: CEN/TC 150/WG 13 - Potentially explosives atmospheres
• Current Stage: 3098 - Decision to reject - Consensus building
• Start Date: 07-Nov-2008
• Completion Date: 07-Nov-2008
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Directive: 94/9/EC - Directive 94/9/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Mandate: M/BC/CEN/92/46 - Standardization mandate assigned to CEN/CENELEC concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Ref Project: oSIST prEN 1755:2022 - Industrial Trucks - Safety requirements and verification - Supplementary requirements for operation in potentially explosive atmospheres

Relations

• Revises: EN 1755:2000 - Safety of industrial trucks - Operation in potentially explosive atmospheres - Use in flammable gas, vapour, mist and dust
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 1755:2022
01-januar-2022
Vozila za talni transport - Varnostne zahteve in preverjanje - Dodatne zahteve za
delovanje v potencialno eksplozivnih atmosferah
Industrial Trucks - Safety requirements and verification - Supplementary requirements for
operation in potentially explosive atmospheres
Flurförderzeuge - Sicherheitsanforderungen und Verifizierung - Zusätzliche
Anforderungen für den Einsatz in explosionsgefährdeten Bereichen
Chariots de manutention - Prescriptions de sécurité et vérification - Prescriptions
supplémentaires pour le fonctionnement en atmosphères explosibles
Ta slovenski standard je istoveten z: prEN 1755
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
53.060 Industrijski tovornjaki Industrial trucks
oSIST prEN 1755:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 1755:2022

---------------------- Page: 2 ----------------------
oSIST prEN 1755:2022


DRAFT
EUROPEAN STANDARD
prEN 1755
NORME EUROPÉENNE

EUROPÄISCHE NORM

October 2021
ICS 53.060 Will supersede EN 1755:2015
English Version

Industrial Trucks - Safety requirements and verification -
Supplementary requirements for operation in potentially
explosive atmospheres
Chariots de manutention - Prescriptions de sécurité et Flurförderzeuge - Sicherheitsanforderungen und
vérification - Prescriptions supplémentaires pour le Verifizierung - Zusätzliche Anforderungen für den
fonctionnement en atmosphères explosibles Einsatz in explosionsgefährdeten Bereichen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 150.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.


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. prEN 1755:2021 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 10
4 Safety requirements and/or protective measures . 13
4.1 General. 13
4.2 Hot surfaces . 14
4.2.1 General. 14
4.2.2 Temperature monitoring . 14
4.2.3 Temperature classification . 15
4.3 Safety shutdown . 15
4.4 Mechanically generated sparks . 16
4.4.1 Load handling devices . 16
4.4.2 Fans of electrical equipment. 16
4.4.3 Radiator fans on IC-engines . 16
4.4.4 Other fans . 16
4.4.5 Other rotating parts . 17
4.5 Electrical system . 17
4.5.1 General. 17
4.5.2 Electrical equipment. 18
4.5.3 Electrical system bipolarity . 19
4.5.4 Insulation monitoring . 20
4.5.5 Battery and battery connectors . 20
4.6 Category 3G trucks equipped with restricted breathing enclosures “nR” and gas
detection systems . 20
4.6.1 General. 20
4.6.2 Gas detection systems . 21
4.6.3 Gas sensors . 22
4.6.4 Restricted breathing enclosures “nR” in combination with a gas detection system . 23
4.7 Internal combustion engines . 23
4.8 Electrostatic risks . 23
4.8.1 Bonding . 23
4.8.2 Circuit resistance . 24
4.8.3 Non-conductive parts . 24
4.8.4 Transmission belts . 25
4.8.5 Hydraulic systems . 26
4.8.6 Castors and wheels . 26
4.9 Requirements for brakes, clutches and couplings . 27
4.9.1 General. 27
4.9.2 Mechanical clutches and couplings . 27
4.9.3 Hydrokinetic clutches . 27
4.9.4 Service brakes and friction clutches for category 3G and 3D trucks . 28
4.9.5 Service brakes and friction clutches for category 2G trucks . 28
2

---------------------- Page: 4 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
4.9.6 Service brakes and friction clutches for category 2D trucks . 29
4.9.7 Parking brakes . 29
4.9.8 Emergency stop brake . 29
4.10 Requirements for pneumatic systems . 29
4.11 Flammability of non-metallic materials . 29
5 Verification of safety requirements and/or protective measures . 30
5.1 Determination of the maximum surface temperatures . 30
5.1.1 General . 30
5.1.2 Test conditions . 30
5.1.3 Test procedures . 30
5.1.4 Measurements . 33
5.2 Measurement of circuit resistance and capacitance . 34
5.2.1 Verification and tests of circuit resistance and bonding resistance . 34
5.2.2 Measurement of capacitance of insulated metal parts . 35
6 Information for use . 35
6.1 General . 35
6.2 Instruction handbook . 35
6.2.1 Operation of the truck. 35
6.2.2 Service and maintenance of the truck . 35
6.2.3 Additional safety information . 37
6.2.4 Information for charging of the battery and battery handling . 37
6.3 Marking . 38
6.3.1 General . 38
6.3.2 Minimum marking . 38
6.3.3 Additional marking according to this document (Ex - marking). 38
6.4 Warning labels . 39
Annex A (normative) List of significant hazards . 40
Annex B (informative) Relationship between zones (area classification) and truck categories
. 41
Annex C (informative) Typical example of cladding of load handling devices . 42
Annex D (informative) Typical examples of non-conductive surface areas according to
4.8.3.1 . 44
Annex E (normative) Requirements for transmission belts in accordance with
ISO 9563:2015 or ISO 1813:2014 . 47
Annex F (informative) Significant technical changes between this document and the
previous edition of this European Standard . 48
Annex G (informative) Warning labels for trucks with restricted breathing enclosure(s) in
combination with gas detection system . 50
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/34/EU aimed to be covered . 51
Bibliography . 54

3

---------------------- Page: 5 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
European foreword
This document (prEN 1755:2021) has been prepared by Technical Committee CEN/TC 150 “Industrial
Trucks - Safety”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1755:2015.
In comparison with the previous edition, the following technical modifications have been made:
• Inclusion of requirements for driverless trucks;
• Requirements of EN 1175:2020 have been assessed and clarified where appropriate;
• Removal of requirement b) for brake materials as does not represent state of the art in brake material
technology;
• Normative standard references updated.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part
of this document.
4

---------------------- Page: 6 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
Introduction
This document is a type-C standard as stated in EN ISO 12100:2010.
This document is of relevance, in particular, for the following stakeholder groups representing the market
players with regard to machinery safety:
• machine manufacturers (small, medium and large enterprises);
• health and safety bodies (regulators, accident prevention organizations, market surveillance, etc.).
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
• machine users/employers (small, medium and large enterprises);
• machine users/employees (e.g. trade unions, organizations for people with special needs);
• service providers, e.g. for maintenance (small, medium and large enterprises);
• consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting
process of this document.
The machines concerned and the extent to which hazards, hazardous situations or hazardous events are
covered are indicated in the Scope of this document.
When requirements of this type-C standard are different from those which are stated in type-A or type B
standards, the requirements of this type-C standard take precedence over the requirements of the other
standards for machines that have been designed and built according to the requirements of this type-C
standard.
This document covers specific safety requirements where industrial trucks will operate in potentially
explosive atmospheres that are not covered exhaustively by:
• EN 1459-1:2017+A1:2020 and EN 1459-2:2015+A1:2018;
• ISO 24134:2006;
5
• EN ISO 3691-1:2015 ;
• EN ISO 3691-2:2016;
• EN ISO 3691-3:2016;
• EN ISO 3691-4:2020;
1
;
• EN ISO 3691-5:2015
• EN ISO 3691-6:2015.

1
As impacted by EN ISO 3691-5:2015/A1:2020.
5

---------------------- Page: 7 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
Assessment of hazards
The product needs to be designed in such a way that it is fit for its purpose or function and can be adjusted
and maintained without putting persons at risk when used under the conditions foreseen by the
manufacturer.
In order to properly design a product and to cover all specific safety requirements, the manufacturer
needs to identify the hazards that apply to their product and carry out a risk assessment. The
manufacturer then needs to design and construct the product taking this assessment into account.
The aim of this procedure is to eliminate the risk of accidents throughout the foreseeable lifetime of the
machinery, including the phases of assembling and dismantling where risks of accidents can also arise
from foreseeable abnormal situations.
In selecting the most appropriate methods, the manufacturer needs to apply the following principles, in
the order given here:
a) eliminate or reduce risks as far as possible by design (inherently safe machinery design and
construction);
b) take the necessary protective measures in relation to risks that cannot be eliminated by design;
c) inform users of any shortcoming of the protective measures adopted;
d) indicate whether any particular training is required;
e) specify any need to provide personal protection equipment;
f) refer to the appropriate user's document for proper operating instructions.
Industrial trucks need to be designed to prevent foreseeable misuse wherever possible, if such would
engender risk. In other cases, the manufacturer's instructions need to draw the user's attention to ways
shown by experience in which the machinery ought not to be used.
This document does not repeat all the technical rules which are state-of-the-art, and which are applicable
to the material used to construct the industrial truck. Refer to ISO 12100:2010.
6

---------------------- Page: 8 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
1 Scope
This document applies to self-propelled and pedestrian propelled manual and semi-manual industrial
trucks as defined in ISO 5053-1:2020 including their load handling devices and attachments (hereafter
referred to as trucks) intended for use in potentially explosive atmospheres.
NOTE 1 Attachments mounted on the load carrier or on fork arms which are removable by the user are not
considered to be a part of the truck.
This document specifies supplementary technical requirements for the prevention of the ignition of an
explosive atmosphere of flammable gases, vapours, mists or dusts by industrial trucks of equipment
group II and equipment category 2G, 3G, 2D or 3D.
NOTE 2 The relationship between an equipment category (hereafter referred to as category) and the
corresponding zone (area classification) is shown in informative Annex B.
This document is not applicable to:
• trucks of equipment group I;
• trucks of equipment group II, equipment category 1;
• trucks intended for use in potentially explosive atmospheres with hybrid mixtures;
• protective systems.
This document is not applicable to trucks intended for use in potentially explosive atmospheres of carbon
disulphide (CS ), carbon monoxide (CO) and/or ethylene oxide (C H O) due to the special properties of
2 2 4
these gases.
Technical requirements relating to lithium-ion batteries and fuel cells as energy sources are not given in
this document due to their specific hazards.
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.
EN 1127-1:2019, Explosive atmospheres - Explosion prevention and protection - Part 1: Basic concepts and
methodology
EN 1149-5:2018, Protective clothing - Electrostatic properties - Part 5: Material performance and design
requirements
EN 1175:2020, Safety of industrial trucks - Electrical/electronic requirements
EN 1459-1:2017+A1:2020, Rough-terrain trucks - Safety requirements and verification - Part 1: Variable-
reach trucks
EN 1459-2:2015+A1:2018, Rough-terrain trucks - Safety requirements and verification - Part 2: Slewing
variable-reach trucks
EN 1834-1:2000, Reciprocating internal combustion engines - Safety requirements for design and
construction of engines for use in potentially explosive atmospheres - Part 1: Group II engines for use in
flammable gas and vapour atmospheres
7

---------------------- Page: 9 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
EN 1834-3:2000, Reciprocating internal combustion engines - Safety requirements for design and
construction of engines for use in potentially explosive atmospheres - Part 3: Group II engines for use in
flammable dust atmospheres
EN 14986:2017, Design of fans working in potentially explosive atmospheres
EN 50271:2018, Electrical apparatus for the detection and measurement of combustible gases, toxic gases
or oxygen - Requirements and tests for apparatus using software and/or digital technologies
2
EN 60079-7:2015, Explosive atmospheres - Part 7: Equipment protection by increased safety “e”
(IEC 60079-7:2015)
EN 60079-14:2014, Explosive atmospheres - Part 14: Electrical installations design, selection and erection
(IEC 60079-14:2014)
EN 60079-17:2014, Explosive atmospheres - Part 17: Electrical installations inspection and maintenance
(IEC 60079-17:2013)
EN 60079-29-1:2016, Explosive atmospheres - Part 29-1: Gas detectors - Performance requirements of
detectors for flammable gases (IEC 60079-29-1:2016)
EN 60079-29-2:2015, Explosive atmospheres - Part 29-2: Gas detectors - Selection, installation, use and
maintenance of detectors for flammable gases and oxygen (IEC 60079-29-2:2015)
EN 60079-29-3:2014, Explosive atmospheres - Part 29-3: Gas detectors - Guidance on functional safety of
fixed gas detection systems (IEC 60079-29-3:2014)
EN 60079-31:2014, Explosive atmospheres - Part 31: Equipment dust ignition protection by enclosure "t"
(IEC 60079-31:2013)
3
EN 60384-14:2013, Fixed capacitors for use in electronic equipment - Part 14: Sectional specification -
Fixed capacitors for electromagnetic interference suppression and connection to the supply mains
(IEC 60384-14:2013)
4
EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)
EN 60695-11-10:2013, Fire hazard testing - Part 11-10: Test flames - 50 W horizontal and vertical flame
test methods (IEC 60695-11-10:2013)
EN 61508-1:2010, Functional safety of electrical/electronic/programmable electronic safety-related
systems - Part 1: General requirements (IEC 61508-1:2010)
EN 61508-6:2010, Functional safety of electrical/electronic/programmable electronic safety-related
systems - Part 6: Guidelines on the application of IEC 61508-2 and IEC 61508-3 (IEC 61508-6:2010)

2
As impacted by EN 60079-7:2015/A1:2018.
3
As impacted by EN 60384-14:2013/A1:2016.
4
As impacted by EN 60529:1991/A1:2000 and EN 60529:1991/A2:2013.
8

---------------------- Page: 10 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
EN IEC 60079-0:2018, Explosive atmospheres - Part 0: Equipment - General requirements
(IEC 60079-0:2017)
EN IEC 60079-15:2019, Explosive atmospheres - Part 15: Equipment protection by type of protection "n"
(IEC 60079-15:2017)
EN ISO 284:2012, Conveyor belts - Electrical conductivity - Specification and test method (ISO 284:2012)
5
EN ISO 3691-1:2015, Industrial trucks - Safety requirements and verification - Part 1: Self -propelled
industrial trucks, other than driverless trucks, variable-reach trucks and burden-carrier trucks
(ISO 3691-1:2011)
EN ISO 3691-4:2020, Industrial trucks - Safety requirements and verification - Part 4: Driverless industrial
trucks and their systems (ISO 3691-4:2020)
EN ISO 13849-1:2015, Safety of machinery - Safety-related parts of control systems - Part 1: General
principles for design (ISO 13849-1:2015)
EN ISO 20344:2011, Personal protective equipment - Test methods for footwear (ISO 20344:2011)
EN ISO 80079-36:2016, Explosive atmospheres - Part 36: Non-electrical equipment for explosive
atmospheres - Basic method and requirements (ISO 80079-36:2016)
EN ISO 80079-37:2016, Explosive atmospheres - Part 37: Non-electrical equipment for explosive
atmospheres - Non-electrical type of protection constructional safety ''c'', control of ignition sources ''b'',
liquid immersion ''k'' (ISO 80079-37:2016)
CLC/TR 60079-32-1:2018, Explosive atmospheres - Part 32-1: Electrostatic hazards, guidance
IEC/TS 60079-46:2017, Explosive atmospheres - Part 46: Equipment assemblies
ISO 1813:2014, Belt drives — V-ribbed belts, joined V-belts and V-belts including wide section belts and
hexagonal belts — Electrical conductivity of antistatic belts: Characteristics and methods of test
ISO 9563:2015, Belt drives — Electrical conductivity of antistatic endless synchronous belts —
Characteristics and test method
ISO 15870:2000, Powered industrial trucks — Safety signs and hazard pictorials — General principles

5
As impacted by EN ISO 3691-1:2015/A1:2020
9

---------------------- Page: 11 ----------------------
oSIST prEN 1755:2022
prEN 1755:2021 (E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
explosive atmosphere
mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours,
mists or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture
[SOURCE: EN 13237:2012, 3.28]
3.2
potentially explosive atmosphere
atmosphere which could become explosive due to local and operational conditions
[SOURCE: EN 13237:2012, 3.28.2]
3.3
hybrid mixture
mixture of flammable substances with air in different physical states
[SOURCE: EN 13237:2012, 3.40]
3.4
auto ignition temperature
lowest temperature (of a hot surface) at which under specified test conditions an ignition of a flammable
gas or flammable vapour in mixture with air or air/inert gas occurs
[SOURCE: EN 13237:2012, 3.45]
3.5
minimum ignition temperature of a dust cloud
lowest temperature of a hot surface on which the most ignitable mixture of the dust with air is ignited
under specified test conditions
[SOURCE: EN 13237:2012, 3.45.1]
3.6
minimum ignition temperature of a dust layer
lowest temperature of a hot surface at which ignition occurs in a dust layer under specified test conditions
[SOURCE: EN 13237:2012, 3.45.2]
10

---------------------- Page: 12 ----------------------
oSIST prEN 1755:2
...