SIST EN 953:2000+A1:2009

Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards

This European Standard specifies general requirements for the design and construction of guards provided primarily to protect persons from mechanical hazards.
The standard applies primarily to machines which are manufactured after the date of issue of this standard.
Attention is drawn to the use of guards to minimise exposure to non-mechanical hazards.
The requirements are applicable if fixed and movable guards are used. The standard does not cover those parts of guards which actuate interlocking devices. These are covered in EN 1088.
This standard does not provide requirements for special systems relating specifically to mobility and ability to lift loads like rollover protective structures (ROPS) and falling-object protective structures (FOPS).

Sicherheit von Maschinen - Trennende Schutzeinrichtungen - Allgemeine Anforderungen an Gestaltung und Bau von feststehenden und beweglichen trennenden Schutzeinrichtungen

Sécurité des machines - Protecteurs - Prescriptions générales pour la conception et la construction des protecteurs fixes et mobiles

La présente norme européenne spécifie les prescriptions générales applicables à la conception et à la construction
de protecteurs destinés essentiellement à protéger les personnes contre les risques mécaniques.
La norme s'applique avant tout aux machines construites après la date de publication de cette norme.
L'attention est attirée sur la mise en oeuvre des protecteurs pour réduire au mieux l'exposition aux risques non
mécaniques.
Les prescriptions sont applicables quand des protecteurs fixes et mobiles sont utilisés. La norme ne traite
pas des éléments constitutifs des protecteurs qui actionnent les dispositifs de verrouillage. Ceux-ci sont traités
dans l'EN 1088.
La présente norme ne donne pas de prescriptions pour les systèmes de protection spécifiques à la mobilité ou
au levage des charges tels que les structures de protection contre le retournement (ROPS) et les structures
de protection contre le risque de chutes d'objets (FOPS).

Varnost strojev - Varovala - Splošne zahteve za načrtovanje in konstruiranje pritrjenih in premičnih varoval

General Information

• Status: Withdrawn
• Publication Date: 06-Apr-2009
• Withdrawal Date: 09-Dec-2015
• ICS: 13.110 - Safety of machinery
• Technical Committee: VSN - Safety of machinery
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 10-Dec-2015
• Due Date: 02-Jan-2016
• Completion Date: 10-Dec-2015
• 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: 98/37/EC - Machinery
• Mandate: M/079 - Mandate to CEN and CENELEC for standardization in the field of machines
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: EN 953:1997+A1:2009 - Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards

Relations

• Replaces: SIST EN 953:2000 - Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards
• Effective Date: 01-May-2009
• Replaced By: SIST EN ISO 14120:2016 - Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards (ISO 14120:2015)
• Effective Date: 01-Feb-2016
• Consolidates: SIST EN 953:2000 - Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2009
9DUQRVWVWURMHY9DURYDOD6SORãQH]DKWHYH]DQDþUWRYDQMHLQNRQVWUXLUDQMH
SULWUMHQLKLQSUHPLþQLKYDURYDO
Safety of machinery - Guards - General requirements for the design and construction of
fixed and movable guards
Sicherheit von Maschinen - Trennende Schutzeinrichtungen - Allgemeine Anforderungen
an Gestaltung und Bau von feststehenden und beweglichen trennenden
Schutzeinrichtungen
Sécurité des machines - Protecteurs - Prescriptions générales pour la conception et la
construction des protecteurs fixes et mobiles
Ta slovenski standard je istoveten z: EN 953:1997+A1:2009
ICS:
13.110 Varnost strojev Safety of machinery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 953:1997+A1
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2009
ICS 13.110 Supersedes EN 953:1997
English Version
Safety of machinery - Guards - General requirements for the
design and construction of fixed and movable guards
Sécurité des machines - Protecteurs - Prescriptions Sicherheit von Maschinen - Trennende
générales pour la conception et la construction des Schutzeinrichtungen - Allgemeine Anforderungen an
protecteurs fixes et mobiles Gestaltung und Bau von feststehenden und beweglichen
trennenden Schutzeinrichtungen
This European Standard was approved by CEN on 26 March 1997 and includes Amendment 1 approved by CEN on 8 February 2009.

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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 953:1997+A1:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .4
Introduction .5
1 Scope .5
2 Normative references .5
3 Definitions .6
4 Risk assessment . 13
5 Principal requirements for the design and construction of guards . 13
5.1 Machine aspects . 13
5.1.1 General . 13
5.1.2 Access to danger zones . 13
5.1.3 Containment of ejected parts . 13
5.1.4 Containment of hazardous substances . 14
5.1.5 Noise . 14
5.1.6 Radiation . 14
5.1.7 Explosion . 14
5.2 Human aspects . 14
5.2.1 General . 14
5.2.2 Safety distances. 14
5.2.3 Control of access to the danger zone. 14
5.2.4 Viewing . 14
5.2.5 Ergonomic aspects . 14
5.2.6 Intended use . 15
5.3 Guard design aspects . 15
5.3.1 General . 15
5.3.2 Crushing or trapping points . 15
5.3.3 Durability . 15
5.3.4 Hygiene . 16
5.3.5 Cleaning . 16
5.3.6 Exclusion of contaminants . 16
5.4 Guard construction aspects . 16
5.4.1 Sharp edges etc. . 16
5.4.2 Integrity of joints . 16
5.4.3 Removal only by tool . 16
5.4.4 Positive location of removable guards . 16
5.4.5 Positive closing of movable guards . 16
5.4.6 Self closing guards . 16
5.4.7 Adjustable guards. 17
5.4.8 Movable guards . 17
5.4.9 Control guards . 17
5.5 Selection of materials . 17
5.5.1 General . 17
5.5.2 Impact resistance. 18
5.5.3 Rigidity . 18
5.5.4 Secure fixing . 18
5.5.5 Reliability of moving parts . 18
5.6 Containment . 18
5.7 Resistance to corrosion . 18
5.8 Resistance to micro-organisms . 18
5.9 Non-toxicity . 18
5.10 Machine viewing . 18
5.11 Transparency . 19
5.12 Stroboscopic effects . 19
5.13 Electrostatic properties . 19
5.14 Thermal stability . 19
5.15 Flammability . 19
5.16 Noise and vibration reduction . 19
5.17 Radiation protection . 19
6 Selection of types of guards . 20
6.1 General . 20
6.2 Combination of different guards or of guards with other devices . 20
6.3 Selection of guards according to the number and location of the hazards . 22
6.4 Selection of guards according to the nature and frequency FOR access required . 23
6.4.1 Moving transmission parts . 23
6.4.2 Where access is not required during use . 23
6.4.3 Where access is required during use . 23
7 Additional design and construction considerations . 23
7.1 Climbing . 23
7.2 Retained fastenings . 24
7.3 Vibration resistance . 24
7.4 Warning signs . 24
7.5 Colour . 24
7.6 Aesthetics. 24
8 Verification of the safety requirements for guards . 24
8.1 General . 24
8.2 Impact strength . 25
8.3 Safety distances . 25
8.4 Containment . 25
8.5 Noise . 25
8.6 Guard operating forces . 25
8.7 Visibility . 25
9 Information for use . 25
9.1 General . 25
9.2 Guard hazards . 25
9.3 Installation . 26
9.4 Operation . 26
9.5 Removal of guards . 26
9.6 Inspection and maintenance . 26
Annex A (normative) Guidelines to assist in the selection of guards against hazards generated by
moving parts . 27
Annex B (normative) Guidelines for the selection of guards according to the number and location
of hazards . 28
Annex ZA (informative) !!!!Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/EC"" . 30
""
Annex ZB (informative) !!!!Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC"""" . 31
!!!!Bibliography"""" . 32

Foreword
This document (EN 953:1997+A1:2009) has been prepared by Technical Committee CEN/TC 114 “Safety of
machinery”, the secretariat of which is held by DIN.
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 2009, and conflicting national standards shall be
withdrawn at the latest by December 2009.
This document includes Amendment 1, approved by CEN on 2009-02-08.
This European Standard supersedes EN 953:1997.
The start and finish of text introduced or altered by amendment is indicated in the text by tags !".
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
!For relationship with EU Directive(s), see informative Annexes ZA and ZB, which are integral parts of this
document."
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and United Kingdom.

Introduction
This European Standard specifies general principles for the design and construction of guards, both fixed and
movable. It is intended for use by manufacturers, designers, standards makers and other interested parties.
!This document is a type B standard as stated in EN ISO 12100-1.
The provisions of this document can be supplemented or modified by a type C standard.
NOTE For machines which are covered by the scope of a type C standard and which have been designed and built
according to the provisions of that standard, the provisions of that type C standard take precedence over the provisions of
this type B standard."
In accordance with the requirements laid down in !EN ISO 12100-1" and !EN ISO 12100-2" the
machine designer shall identify the hazards present at a machine, carry out a risk assessment and reduce risk
by design before considering safeguarding techniques.
1 Scope
This European Standard specifies general requirements for the design and construction of guards provided
primarily to protect persons from mechanical hazards.
The standard applies primarily to machines which are manufactured after the date of issue of this standard.
Attention is drawn to the use of guards to minimise exposure to non-mechanical hazards.
The requirements are applicable if fixed and movable guards are used. The standard does not cover those
parts of guards which actuate interlocking devices. These are covered in EN 1088.
This standard does not provide requirements for special systems relating specifically to mobility and ability to
lift loads like rollover protective structures (ROPS) and falling-object protective structures (FOPS).
2 Normative references
!The following referenced documents are indispensable for the application of this European Standard. For
dated references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies."
!deleted text"
EN 349, Safety of machinery – Minimum gaps to avoid crushing of parts of the human body
EN 626-1, Safety of machinery – Reduction of risks to health from hazardous substances emitted by
machinery – Part 1: Principles and specifications for machinery manufacturers
!deleted text"
EN 1088, Safety of machinery – Interlocking devices associated with guards – Principles for design and
selection
EN 1127-1, Explosive atmospheres – Explosion prevention and protection – Part 1: Basic concepts and
methodology
EN 1672-2, Food processing machinery – Basic concepts – Part 2: Hygiene requirements
EN 60204-1, Safety of machinery – Electrical equipment of machines – Part 1: General requirements !(IEC
60204-1:2005, modified)"
!EN ISO 12100-1:2003, Safety of machinery – Basic concepts, general principles for design – Part 1: Basic
terminology, methodology (ISO 12100-1:2003)"
!EN ISO 12100-2:2003, Safety of machinery – Basic concepts, general principles for design – Part 2:
Technical principles (ISO 12100-2:2003)"
!EN ISO 13857, Safety of machinery – Safety distances to prevent hazard zones being reached by upper
and lower limbs (ISO 13857:2008)"
!EN ISO 14121-1, Safety of machinery – Risk assessment – Part 1: Principles (ISO 14121-1:2007)"
Additional information is given in !the Bibliography".
3 Definitions
!For the purposes of this document, the terms and definitions given in EN ISO 12100-1:2003 and the
following apply."
3.1
guard
!physical barrier, designed as part of the machine, to provide protection
NOTE 1 A guard may act:
 alone; it is then only effective when it is "closed" for a movable guard or "securely held in place" for a fixed guard;
 in conjunction with an interlocking device with or without guard locking; in this case, protection is ensured whatever
the position of the guard.
NOTE 2 Depending on its design, a guard may be called e.g. casing, shield, cover, screen, door, enclosing guard.
NOTE 3 See EN ISO 12100-2:2003, 5.3.2 and EN ISO 12100-2:2003/prA1:2008, 5.3.2.4 for types of guards and their
requirements.
[EN ISO 12100-1:2003, 3.25]"
3.2
fixed guard
!guard affixed in such a manner (e.g. by screws, nuts, welding) that it can only be opened or removed by
the use of tools or destruction of the affixing means
[EN ISO 12100-1:2003, 3.25.1]"

3.2.1
enclosing guard
guard which prevents access to the danger zone from all sides (see figure 1)

Figure 1 — Example of an enclosing guard totally preventing access to transmission machinery
3.2.2
distance guard
guard which does not completely enclose a danger zone, but which prevents or reduces access by virtue of its
dimensions and its distance from the danger zone, e.g. perimeter fence or tunnel guard (see figures 2 and 3)

Figure 2 — Example of a distance guard
Figure 3 — Example of a distance guard: tunnel guard providing protection at machine feed or
discharge area
3.3
movable guard
!guard which can be opened without the use of tools

[EN ISO 12100-1:2003, 3.25.2]"
3.3.1
power operated guard
movable guard that is operated with the assistance of power from a source other than persons or gravity
3.3.2
self closing guard
movable guard operated by a machine element (e.g. moving table) or by the workpiece or a part of the
machining jig, so that it allows the workpiece (and the jig) to pass and then automatically returns (by means of
gravity, a spring, other external power, etc.) to the closed position as soon as the workpiece has vacated the
opening through which it has been allowed to pass !deleted text"
Figure 4 — Example of a self closing guard
3.3.3
control guard
!special form of an interlocking guard which, once it has reached its closed position, gives a command to
initiate the hazardous machine function(s) without the use of a separate start control
NOTE EN ISO 12100-2:2003, 5.3.2.5, gives detailed provisions regarding the conditions of use.
[EN ISO 12100-1:2003, 3.25.6]"
3.4
adjustable guard
!fixed or movable guard which is adjustable as a whole or which incorporates adjustable part(s)
[EN ISO 12100-1:2003, 3.25.3 and EN ISO 12100-1:2003/prA1:2008]"
!!3.4.1
!!
manually adjustable guard
adjustable guard where the adjustment is made manually and the adjustment remains fixed during a particular
operation
NOTE See also Figure 5."
The guard is telescopic to provide ready
adjustment to the surface of the workpiece. It is
attached to a hinge to permit access to the
spindle for drill changing.
Figure 5 — Example of an adjustable guard for a radial or pedestal drilling machine
!!!!3.4.2
automatically adjustable guard
adjustable guard where the adjustment is made automatically during a particular operation
NOTE A self closing guard can also be an automatically adjustable guard."

3.5
interlocking guard
!guard associated with an interlocking device so that, together with the control system of the machine, the
following functions are performed:
 the hazardous machine functions "covered" by the guard cannot operate until the guard is closed;
 if the guard is opened while hazardous machine functions are operating, a stop command is given;
 when the guard is closed, the hazardous machine functions "covered" by the guard can operate. The
closure of the guard does not by itself start the hazardous machine functions
NOTE ISO 14119 gives detailed provisions.
[EN ISO 12100-1:2003, 3.25.4]
(See also Figure 6 and Figure 7 and EN 1088.)"
Figure 6 — Example of interlocking hinged guards; these enclose the danger zone when closed

Figure 7 — Example of interlocking sliding guards

3.6
interlocking guard with guard locking
!guard associated with an interlocking device and a guard locking device so that, together with the control
system of the machine, the following functions are performed:
 the hazardous machine functions “covered” by the guard cannot operate until the guard is closed and
locked;
 the guard remains closed and locked until the risk due to the hazardous machine functions "covered" by
the guard has disappeared;
 when the guard is closed and locked, the hazardous machine function "covered” by the guard can
operate. The closure and locking of the guard do not by themselves start the hazardous machine
functions.
NOTE ISO 14119 gives detailed provisions.
[EN ISO 12100-1:2003, 3.25.5]
(See also Figure 8 and EN 1088.)"

a) Interlocking guard in the open position
b) Example of guard locking device
Figure 8 — Example of safeguarding of drilling machine using interlocking guards with guard locking
and fixed guards
3.7
guard closed position
a guard is closed when it performs the function for which it was designed to prevent/reduce access to the
danger zone and/or reduce exposure to hazards such as noise, radiation etc.
3.8
guard open
a guard is open when it is not closed
3.9
tool
implement such as a key or wrench designed to operate a fastener. An improvised implement such as a coin
or nailfile cannot be considered to be a tool
3.10
use of a tool
use of a tool by an authorised person under known and predetermined circumstances as part of a safe system
of work
3.11
frequency of access
number of occasions on which access is required or foreseeable within the guarded area per unit of time.
4 Risk assessment
In order to select and design types of guards appropriate to particular machinery, it is important to assess the
risk arising from the various hazards present at that machinery and the foreseeable categories of persons at
risk !(see EN ISO 12100-1:2003, Clause 5 and EN ISO 14121-1)".
5 Principal requirements for the design and construction of guards
5.1 Machine aspects
5.1.1 General
Proper consideration of foreseeable aspects of the machine environment and operation throughout the
foreseeable life of the machine is necessary in the design and application of guards. Inadequate consideration
of these aspects can lead to unsafe or inoperable machinery. This in turn can lead persons to defeat the
guards provided thus exposing them to greater risk.
5.1.2 Access to danger zones
To minimise access to danger zones where practicable, guards and machinery shall be so designed as to
enable routine adjustments, lubrication and maintenance to be carried out without opening or removing the
guards.
Where access is required within the guarded area this shall be as free and unobstructed as practicable. The
following are examples of reasons for access.
 Loading and unloading
 Tool changing and setting;
 Measurement, gauging and sampling;
 Process observation;
 Maintenance and repair;
 Lubrication;
 Removal of waste material (e.g. scrap, swarf, spillage);
 Obstruction removal;
 Cleaning and hygiene.
5.1.3 Containment of ejected parts
Where there is a foreseeable risk of ejection of parts (e.g. broken tooling, workpiece) from the machine, the
guard shall as far as practicable be designed and constructed from appropriate materials selected to contain
these.
5.1.4 Containment of hazardous substances
Where there is a foreseeable risk of emission from the machine of hazardous substances (e.g. coolant,
vapours,
...