EN 842:1996+A1:2008

SLOVENSKI STANDARD
01-december-2008
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Safety of machinery - Visual danger signals - General requirements, design and testing
Sicherheit von Maschinen - Optische Gefahrensignale - Allgemeine Anforderungen,
Gestaltung und Prüfung
Sécurité des machines - Signaux visuels de danger - Exigences générales, conception et
essais
Ta slovenski standard je istoveten z: EN 842:1996+A1:2008
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 842:1996+A1
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2008
ICS 13.110 Supersedes EN 842:1996
English Version
Safety of machinery - Visual danger signals - General
requirements, design and testing
Sécurité des machines - Signaux visuels de danger - Sicherheit von Maschinen - Optische Gefahrensignale -
Exigences générales, conception et essais Allgemeine Anforderungen, Gestaltung und Prüfung
This European Standard was approved by CEN on 30 November 1995 and includes Amendment 1 approved by CEN on 14 August 2008.

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: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 842:1996+A1:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Definitions .4
4 Safety and ergonomic requirements .5
4.1 General.5
4.2 Detectibility.5
4.3 Discriminability .9
4.4 Glare.9
4.5 Distance .9
4.6 Duration .10
5 Physical measurements.10
6 Subjective visual check .10
Annex A (informative) Bibliography .11
Annex ZA (informative) !!!!Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/EC, amended by 98/79/EC"""" .12
Annex ZB (informative) !!!!Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC"""".13

Foreword
This document (EN 842:1996+A1:2008) has been prepared by Technical Committee CEN/TC 122
“Ergonomics”, 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 March 2009, and conflicting national standards shall be withdrawn at
the latest by December 2009.
This document includes Amendment 1, approved by CEN on 2008-08-14.
This document supersedes EN 842:1996.
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."
On the international level the International Standard ISO 11428 "Ergonomics – Visual danger signals –
General requirements, design and testing" has been prepared by WG 3 "Danger signs and speech
communication in noisy environments" of ISO/TC 159/SC 5 "Ergonomics of the physical environment". The
technical content of both the European Standard EN 842 and the International Standard ISO 11428 is
identical, however the limits of applicability of the standards to other technical fields are different.
Due to the different limits of applicability still existing on the European and international level direct
transformation of the International Standard into a European Standard is not possible. The reason is that EN
842 has been prepared in order to fulfil the essential safety and health requirements of annex 1 of the Council
Directive 89/392/EEC of 14 June 1989 on the approximation of the laws of the Member States relating to
machinery: Essential health and safety requirements relating to the design and construction of machinery (see
annex A of EN 292-2:1991/A1:1995) and that therefore the limits of applicability of the European Standard is
restricted to this Directive.
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.

1 Scope
This European Standard describes criteria for the perception of visual danger signals in the area that people
are intended to perceive and to react to such a signal. It specifies the safety and ergonomic requirements and
the corresponding physical measurements and subjective visual check. It also provides guidance for the
design of the signals to be clearly perceived and differentiated as described in 5.3 of EN 292-2:1991.
This European Standard does not apply to danger indicators:
 Presented in either written or pictorial form;
 Transmitted by data display units.
This European Standard does not apply to special regulations such as those for public disaster and public
transport.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to
this European Standard only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referred to applies.
EN 292-2:1991/A1:1995, Safety of machinery - Basic concepts, general principles for design - Part 2:
Technical principles and specifications.
EN 60073, Coding of indicating devices and actuators by colours and supplementary means (IEC 73:1991).
EN 61310-1, Safety of machinery – Indicating, marking and actuating – Part 1: Requirements for visual,
auditory and tactile signals (IEC 1310-1:1995).
ISO 3864, Safety colours and safety signs.
3 Definitions
For the purposes of this standard the following definitions apply:
3.1
visual danger signal
visual signal indicating imminent onset, or actual occurrence of a dangerous situation, involving risk of
personal injury or equipment disaster, and requiring some human response to eliminate or control the danger
or requiring other immediate action.
A distinction is made between two types of visual danger signals: visual warning signal and visual emergency
signal.
3.1.1
visual warning signal
visual signal indicating the imminent onset of a dangerous situation requiring appropriate measures for the
elimination or control of the danger

3.1.2
visual emergency signal
visual signal indicating the beginning or the actual occurrence of a dangerous situation requiring immediate
action
3.2
signal reception area
area in which the signal is intended to be perceived and reacted upon
3.3
field of vision (visual field)
physical space visible to an eye in a given position (see also 3.1.10 of ISO 8995:1989)
3.4
danger signal light
light source intended to convey information about the existence of a dangerous situation by means of one or
1)
several characteristics, such as luminance colour, shape, location and temporal pattern
4 Safety and ergonomic requirements
4.1 General
The characteristics of the visual danger signal shall ensure that any person in the signal reception area can
detect, discriminate and react to the signal as intended. Visual danger signals shall be:
 Clearly seen under all possible lighting conditions;
 Clearly discriminated from general lighting and other visual signals;
 Allocated a specific meaning within the signal reception area.
Visual danger signals shall take precedence over all other visual signals.
Visual emergency signals shall take precedence over all visual warning signals.
Care shall be taken to review the effectiveness of the visual danger signals at regular intervals and whenever
a new signal (whether a danger signal or not) is introduced in the signal reception area.
NOTE 1 A visual danger signal should, if not contradicted by special reasons, be associated with an auditory danger
signal. When the danger signal is an emergency signal, auditory and visual signals should be presented together (see EN
981).
NOTE 2 It could be advantageous for visual danger signals to have a relatively low intensity test mode to indicate they
are functional but not in a warning mode.
4.2 Detectibility
1) 1) 1)
4.2.1 Luminance , illuminance and contrast

1) As defined in ISO 8995
4.2.1.1 General
2)
Two types of light sources need to be distinguished: luminous area sources and luminous point sources .
Luminous area sources have a visual angle greater than 1' (minute) for daylight conditions or 10' (minutes) for
darkness, otherwise the light sources are luminous point sources.
4.2.1.2 Luminous area sources
In all cases when the light source is not to be regarded as small (point source), the criteria for detectibility
characters are the luminance of the surface, the luminance of the background and their ratio. This luminance
ratio (contrast) is not affected by viewing distance (unless transmittivity is to be taken into account, see 4.5) so
a specified luminance ratio can be considered adequate for a wide range of viewing conditions.
The luminance of a visual warning signal shall be at least five times the luminance of the background. The
luminance of a visual emergency signal shall be at least twice that of a warning signal, i.e. at least ten times
the luminance of the background.
4.2.1.3 Luminous point sources
For luminous point sources, the criterion for detectibility is the illuminance produced by the luminous flux on
the pupil of the observer's eye compared to the luminance of the background.
The relationship between the pupillary illuminance required for detectibility and the background luminance is
given in figure 1.
2) As defined in IEC 50(845)
a) Required pupillary illuminance in Lux
b) Background illuminance in cd/m
Figure 1 — Relationship between the required pupillary illuminance and the background luminance

4.2.2 Flashing lights
Flashing lights shall be used for visual emergency signals.
By having a signal flash, i.e. continuously switching ON and OFF, the detectibility (attention-attracting
qualities) of the signal is usually increased, often accompanied by transmission of a feeling of urgency.
NOTE 1 It is recommended that the flash frequency should be between 2 Hz and 3 Hz with approximatel
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