prEN ISO 21260

SLOVENSKI STANDARD
01-december-2018
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Safety of machinery - Mechanical safety data for physical contacts between moving
machinery and persons (ISO/DIS 21260:2018)
Sicherheit von Maschinen - Mechanische sicherheitsbezogene Daten zu physischen
Kontakten zwischen beweglichen Maschinen oder sich bewegenden Maschinenteilen
und Personen (ISO/DIS 21260:2018)
Sécurité des machines - Données de sécurité mécanique pour les contacts physiques
entre des machines en mouvement ou des parties mobiles de machines et des
personnes (ISO/DIS 21260:2018)
Ta slovenski standard je istoveten z: prEN ISO 21260
ICS:
13.110 Varnost strojev Safety of machinery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT INTERNATIONAL STANDARD
ISO/DIS 21260
ISO/TC 199 Secretariat: DIN
Voting begins on: Voting terminates on:
2018-10-04 2018-12-27
Safety of machinery — Mechanical safety data for physical
contacts between moving machinery or moving parts of
machinery and persons
Sécurité des machines — Données de sécurité mécanique pour les contacts physiques entre des machines en
mouvement ou des parties mobiles de machines et des personnes
ICS: 13.110
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
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STANDARDS MAY ON OCCASION HAVE TO
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POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 21260:2018(E)
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. ISO 2018

ISO/DIS 21260:2018(E)
ISO/DIS 21260:2018(E)
Contents Page
Foreword . vi
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Risk assessment and risk reduction . 2
4.1 General . 2
4.2 Strategy for risk reduction from ISO 12100 . 4
4.3 Risk reduction . 4
4.3.1 Hazard elimination or risk reduction by design . 4
4.3.2 Risk reduction by safeguarding . 4
4.3.3 Risk reduction by the provision of information for use about th e r esid ual risk . 4
5 Methodology . 5
6 Classification of machine-human contact . 6
6.1 General . 6
6.2 Group 1 (G1) — High frequency contact . 6
6.3 Group 2 (G2) — Occasional contact . 7
6.4 Group 3 (G3) — Rare co ntact . 7
6.5 Group 4 (G4) — Static or quasi-static contact . 7
6.6 Group 5 (G5) — Sliding contact . 7
7 Contact parameters. 7
7.1 General . 7
7.2 Energy transfer . 8
7.3 Energy transferred per unit area . 9
7.4 Dynamic force . 9
8 Contact thresholds . 10
8.1 General . 10
8.2 Threshold values — Group 1, group 2 and group 3 contacts . 10
8.3 Threshold values — Group 4 contacts . 11
8.3.1 General . 11
8.3.2 Contact to lift or move a person . 11
8.4 Threshold values — Group 5 contacts . 11
9 Instructions/Information for use . 12
10 Verification and validation . 12
10.1 Verification of contact conditions . 12
10.2 Requi rem ents . 13
© ISO 2018
10.3 Validation . 13
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
10.4 Control system verification and validation . 13
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
Annex A (informative) Model for mechanically caused pain and injury during contact . 14
below or ISO’s member body in the country of the requester.
Annex B (informative) Contact energy transfer . 15
ISO copyright office
CP 401 • Ch. de Blandonnet 8
B.1 General . 15
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org © ISO 2018 – All rights reserved
iii
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO/DIS 21260:2018(E)
Contents Page
Foreword . vi
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Risk assessment and risk reduction . 2
4.1 General . 2
4.2 Strategy for risk reduction from ISO 12100 . 4
4.3 Risk reduction . 4
4.3.1 Hazard elimination or risk reduction by design . 4
4.3.2 Risk reduction by safeguarding . 4
4.3.3 Risk reduction by the provision of information for use about the residual risk . 4
5 Methodology . 5
6 Classification of machine-human contact . 6
6.1 General . 6
6.2 Group 1 (G1) — High frequency contact . 6
6.3 Group 2 (G2) — Occasional contact . 7
6.4 Group 3 (G3) — Rare co ntact . 7
6.5 Group 4 (G4) — Static or quasi-static contact . 7
6.6 Group 5 (G5) — Sliding contact . 7
7 Contact parameters. 7
7.1 General . 7
7.2 Energy transfer . 8
7.3 Energy transferred per unit area . 9
7.4 Dynamic force . 9
8 Contact thresholds . 10
8.1 General . 10
8.2 Threshold values — Group 1, group 2 and group 3 contacts . 10
8.3 Threshold values — Group 4 contacts . 11
8.3.1 General . 11
8.3.2 Contact to lift or move a person . 11
8.4 Threshold values — Group 5 contacts . 11
9 Instructions/Information for use . 12
10 Verification and validation . 12
10.1 Verification of contact conditions . 12
10.2 Requirements . 13
10.3 Validation . 13
10.4 Control system verification and validation . 13
Annex A (informative) Model for mechanically caused pain and injury during contact . 14
Annex B (informative) Contact energy transfer . 15
B.1 General . 15
iii
ISO/DIS 21260:2018(E)
B.2 Energy transfer . 15
B.2.1 General . 15
B.2.2 Large solid object moving freely . 15
B.2.3 Large solid object under continuous power . 17
B.2.4 Large solid object which brakes in response to a contact . 17
B.3 Compliance . 18
B.3.1 General . 18
B.3.2 Large compliant object moving freely . 18
B.3.3 Large compliant object moving under constant power . 18
B.3.4 Large compliant object which brakes in response to contact . 19
B.4 Energy transferred per unit area . 19
B.4.1 General . 19
B.4.2 Small contact areas . 19
B.4.3 Transfer energy or force reduction . 20
Annex C (informative) Examples of possible machine-human contacts . 21
C.1 General . 21
C.2 Example 1: Automatic retraction of an analytical instrument from electron
microscope chamber . 21
C.2.1 General . 21
C.2.2 Product characteristics/requirements . 21
C.2.3 Check for compliance . 21
C.2.4 Conclusion . 22
C.3 Example 2: Simple domestic AGV (concept as an example only) . 22
C.3.1 General . 22
C.3.2 Product characteristics/requirements . 22
C.3.3 Check for compliance . 23
C.3.4 Conclusion . 23
C.4 Example 3: Collapsing telescopic ladder . 24
C.4.1 General . 24
C.4.2 Product characteristics/requirements . 24
C.4.3 Check for compliance . 24
C.4.4 Conclusion . 25
C.5 Example 4: Repositioning of a motor driven height adjustable desk. 25
C.5.1 General . 25
C.5.2 Product characteristics/requirements . 26
C.5.3 Check for compliance . 26
C.5.4 Conclusion . 27
Annex D (informative) Contact surface characteristics . 28
D.1 General . 28
D.2 Surface shape and characteristics . 28
D.3 Edges, points and corners . 28
D.4 Surface finish . 28
Annex E (informative) Secondary effects of machine-human contacts . 29
E.1 General . 29
E.2 Fall onto flat surface . 29
E.2.1 General . 29
E.2.2 Floor compliance to reduce injury . 29
Annex F (informative) Threshold values for slight injury . 32
F.1 Application . 32
F.2 Bruise caused by dynamic contact . 32
iv
ISO/DIS 21260:2018(E)
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 34
Bibliography . 35

v
ISO/DIS 21260:2018(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 on 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 the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 199, Safety of machinery.
vi
ISO/DIS 21260:2018(E)
Introduction
The structure of safety standards in the field of machinery is as follows.
Type-A standards (basic safety standards) give basic concepts, principles for design and general
aspects that can be applied to machinery;
Type-B standards (generic safety standards) dealing with one or more safety aspect(s), or one or more
type(s) of safeguards that can be used across a wide range of machinery:
— type-B1 standards on particular safety aspects (for example, safety distances, surface
temperature, noise);
— type-B2 standards on safeguards (for example, two-hands control devices, interlocking devices,
pressure-sensitive devices, guards);
Type-C standards (machine safety standards) dealing with detailed safety requirements for a
particular machine or group of machines.
This document is a type-B standard as stated in ISO 12100.
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.)
It is possible to 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.
In addition, this document is intended for standardization bodies elaborating type-C standards.
The requirements of this document can be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and
built according to the requirements of that standard, the requirements of that type-C standard take
precedence.
vii
ISO/DIS 21260:2018(E)
Moving machines and machines with moving parts frequently operate in close proximity to or in the
same physical space as people [e.g. train (access), lift doors, machine tools]. In most circumstances, the
moving parts of the machine make no contact with people. Indeed, wherever possible steps are taken to
prevent any contact.
There are however exceptions, for example closing powered doors or moving guards and in some cases
moving parts of machine tools that contact the operator (e.g. parts of packaging machines). Where this
is the case to prevent injury machine specific limits for the contacts are set by individual type-C
standards.
With increased use of motor driven automation and the introduction of machines that operate with
people collaboratively, machine-human contact caused by machine movements are becoming more
likely and more common.
This document defines non-machine specific limits for contacts to prevent injury. It does not set a single
limit that ensures safety but provides different values so that thresholds to match individual cases is
allowed.
It defines values that meet the criteria for "inherently safe design" as specified in ISO 12100:2010,
6.2.2.2.
It also introduces the concept of groups to account for the complexity of conditions that occur when
machines and people operate together to allow a balance between the frequency of contact, the possible
risk and the societal benefit that is permissible from the use of a machine.
In the context of this document contact refers only to the direct mechanical effect on the person being
contacted by the moving machine part. There is a possibility of other secondary or indirect effects due
for example to
— the temperature of the contacting machine part,
— the potential for the contact to cause the person to fall or to be pushed into another hazard (see
Annex E),
— other secondary effect such as electric shock.
These conditions are not within the scope of this document but along with ergonomic principles ought
to be considered when designing a collaborative machine or defining how it is to be used.
Although it is not within the scope of this document the information contained herein can also be useful
for other contact circumstances involving humans, for example falling or colliding with walls or other
objects.
viii
DRAFT INTERNATIONAL STANDARD ISO/DIS 21260:2018(E)

Safety of machinery — Mechanical safety data for physical
contacts between moving machinery or moving parts of
machinery and persons
1 Scope
This document specifies limits for physical contacts between the machine or parts of the machine and
humans that are caused by movement of the machine as part of its intended use or foreseeable misuse.
This document covers all types of machines that are designed to function where people are allowed to
be present and the machine is allowed to make physical contact with those people.
This document includes machines that contact people as part of their function and machines that do not
require human contact. It encompasses interactions that are intentional or unintentional.
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 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction
ISO 13849 (all parts), Safety of machinery — Safety-related parts of control systems
IEC 62061, Safety of machinery — Functional safety of safety-related electrical, electronic and
programmable electronic control systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100:2010 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
machine-human contact
physical contact between a human and any part or parts of a machine that results from movement of
the machine or part of the machine
ISO/DIS 21260:2018(E)
3.4
static or quasi-static contact
contact in which a force is continuously applied
3.5
dynamic contact
contact in which the force rapidly reaches a peak and then falls
Note 1 to entry: Dynamic contacts occur when the person or body part is free to react and move away from the
contact or if the machine is able to react to reduce or move away from the contact.
3.6
moving machinery
any mechanical system or part of a mechanical system that is in motion
3.7
compliance
property of a system to deform under the action of a load
4 Risk assessment and risk reduction
4.1 General
This document supports risk evaluation and reduction process by providing inherently safe limits, links
to risk reduction safeguards and instructions for use for conditions where contact with a human by the
machine is identified.
Inherently safe design by definition (see ISO 12100:2010) includes the following protective measures:
a) limiting the actuating force to a sufficiently low value so that the actuated part does not generate a
mechanical hazard;
b) limiting the mass and/or velocity of the movable elements, and hence their kinetic energy.
This document specifies limits that it is possible to be applied in order to satisfy the definition of
inherently safe design.
It includes links to safeguards and instructions for use for conditions where contact with a human by
the machine is identified.
To apply this document, the procedure for risk assessment and risk reduction specified in ISO 12100
shall be followed. All conditions of use and foreseeable misuse shall be taken into account. See Figure 1.
NOTE Figure 1 is taken from ISO 12100. The text in relation to risk reduction questions have however been
adjusted to show how it relates to this document by referring directly to contact.
ISO/DIS 21260:2018(E)
Figure 1 — Overview of risk assessment/risk reduction (see ISO 12100)
ISO/DIS 21260:2018(E)
4.2 Strategy for risk reduction from ISO 12100
The strategy for risk reduction at the machine is given in ISO 12100:2010, 6.1, and further guidance is
given in ISO 12100:2010, 6.2 (inherent design measures) and 6.3 (safeguarding and complementary
protective measures). This strategy covers the whole life cycle of the machine. The risk reduction
process for a machine requires that hazards are eliminated or reduced through a hierarchy of
measures:
— hazard elimination or risk reduction by design (see ISO 12100:2010, 6.2);
— risk reduction by safeguarding and possibly complementary protective measures
(see ISO 12100:2010, 6.3);
— risk reduction by the provision of information for use about the residual risk
(see ISO 12100:2010, 6.4).
4.3 Risk reduction
4.3.1 Hazard elimination or risk reduction by design
As far as practicable, machine-human contacts shall be eliminated. Moving machines or parts of a
machine that are incapable of generating contact conditions above the values defined in this document
are considered to be inherently safe by design and these contact conditions are not required to be
eliminated.
4.3.2 Risk reduction by safeguarding
4.3.2.1 General
For a moving machine or parts of a machine that are capable of generating contact conditions above the
limits defined in this document, safeguards(s) shall be implemented are required to safely control
and/or prevent the contact conditions. See ISO 12100 and ISO/TR 22100-2.
4.3.2.2 Sensors and control systems that limit contact conditions
Safe contact conditions are able to be achieved through the use of control systems designed to prevent
the contact exceeding the values specified in this document. Through effectiveness of the control system
it is possible to further enhance the use of compliant surfaces or compliant actuator systems that
absorb energy.
Safety functions shall conform to ISO 13849-1 or IEC 62061.
See also 7.1 and 7.3.
4.3.3 Risk reduction by the provision of information for use about the residual risk
If a residual risk of contact above the limits given in this document remains, specific instructions or
information for use covering the residual risk shall be provided.
NOTE The machine designer is permitted to develop a machine that is incapable of generating contact
conditions above the values in this document by implementing a variety of passive and/or active protective
measures in accordance with ISO 12100:2010. This includes the use of control systems designed to prevent the
contact exceeding the values specified in this document. The effectiveness of the risk reduction can be further
enhanced by the use of compliant surfaces or compliant actuator systems that absorb energy.
ISO/DIS 21260:2018(E)
5 Methodology
If a type-C standard exists for the machine that includes contact limits, the limits specified by that type-
C standard shall be used.
NOTE Type-C standards can specify limits directly or by reference to this document.
If there is no type-C standard or it does not include contact limits, the contact limits shall be determined
using this document.
For a given machine a number of different human contacts may be possible. These may be by different
moving parts of the machine or due to different modes of operation or other use conditions. To apply
this document all possible contacts shall be taken into account.
For each contact the following steps (shown in Figure 2) shall be followed:
a) Identify human contact by a moving part of the machine.
b) If the contact could be with the eye or within 50 mm of the eye it is not permitted and shall be
prevented or eliminated.
c) For other contacts, determine the contact classification group (see Clause 6).
d) Determine the allowable contact condition for the contact (see Clause 8).
e) Compare the actual or design contact condition with the allowable condition. If the allowable
condition is not satisfied the design shall be revised until the contact condition is met.
Design changes are allowed to also affect the risk assessment which should be reviewed and if
necessary repeated.
f) Repeat the process for each contact under foreseeable use and misuse conditions.
ISO/DIS 21260:2018(E)
Figure 2 — Flowchart for application
6 Classification of machine-human contact
6.1 General
The acceptability of a contact by a moving machine or parts of a machine varies depending upon the
contact circumstances.
For practical purposes contacts have been divided into the groups given in 6.2 to 6.6.
One classification group could define all of the contact situations but typically there are multiple
classification groups.
In single contacts it is possible to also include dynamic (G1, G2 and G3), static (G4) and sliding (G5)
elements all of which shall be taken into account.
6.2 Group 1 (G1) — High frequency contact
Group 1 comprises dynamic contacts on the same individual more than once every hour, averaged over
a period of eight hours.
ISO/DIS 21260:2018(E)
6.3 Group 2 (G2) — Occasional contact
Group 2 comprises dynamic contacts on the same individual, less than once per hour averaged over a
period of eight hours but more than once a week, or rare dynamic contacts, less than once per week,
that the person being contacted does not expect.
6.4 Group 3 (G3) — Rare contact
Group 3 comprises dynamic contacts on the same individual less than once per week.
6.5 Group 4 (G4) — Static or quasi-static contact
Group 4 comprises any contact where the energy transfer rate is less than 2 J/s or where the contact
force is applied for more than 500 ms.
6.6 Group 5 (G5) — Sliding contact
Group 5 comprises any contact that includes sliding directly on the surface of the skin.
7 Contact parameters
7.1 General
The following parameters shall define threshold values for a contact with any part of the body except
the eyes or within 50 mm of the eyes:
For a G1, G2 or G3 contact to be acceptable:
— There shall be a minimum contact area and no sharp edges or corners (see Annex D for additional
information on contact surfaces).
— The energy transferred per unit area shall be below the threshold level.
— The energy transferred shall be less than the threshold level.
— The dynamic force shall be less than the threshold level.
For a G4 contact to be acceptable:
— There shall be a minimum contact area and no sharp edges or corners (see Annex D for additional
information on contact surfaces).
— The continuously applied force per unit of contact area (pressure) shall be below the threshold
level.
— The continuously applied force shall be below the threshold level.
For a G5 contact to be acceptable:
— The machine contact surface shall be smooth and flat or rounded (see Annex D for additional
information on contact surfaces).
— The maximum shear stress shall be below the threshold level.
ISO/DIS 21260:2018(E)
7.2 Energy transfer
See also Annex B.
When contact occurs, a proportion of the energy in the moving object is transferred to the person. The
amount of energy that is transferred depends upon how much energy is dissipated in other ways.
For an unconstrained person or body part some energy is dissipated by the person or body part
physically moving. This typically happens when the contact is unexpected.
The machine itself can also dissipate energy through its response to the contact by, for example, the use
mechanical braking or deformable elements. For any such system it is important to note that to be
effective the response time for the system used to control the machine and dissipate the energy should
be fast enough to prevent the transferred energy exceeding the limiting values.
For the components of energy transfer during a contact see Figure 3 and Formula (1).

Key
X energy
Y time
kinetic energy of moving part
energy transferred to the body

energy dissipated by the machine in response to contact

energy dissipated by movement of the body or body part in response to contact
Figure 3 — Components of energy transfer during a contact
ISO/DIS 21260:2018(E)
E = E – (E + E ) (1)
T M MD BD
where
E is the energy transferred to the body;
T
E is the kinetic energy of the machine;
M
E is the energy dissipated by the machine in response to contact;
MD
E is the energy dissipated by movement of the body or body part in response to contact.
BD
NOTE Movement of the body or body part will also be influenced by any reaction to the contact. If the contact
is able to be resisted, reducing the energy dissipated and inc
...