EN 12331:2021

SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST EN 12331:2015
Stroji za predelavo hrane - Stroji za mletje mesa - Varnostne in higienske zahteve
Food processing machinery - Mincing machines - Safety and hygiene requirements
Nahrungsmittelmashinen - Wölfe - Sicherheits- und Hygieneanforderungen
Machines pour les produits alimentaires - Hachoirs - Prescriptions relatives à la sécurité
et l'hygiène
Ta slovenski standard je istoveten z: EN 12331:2021
ICS:
67.260 Tovarne in oprema za živilsko Plants and equipment for the
industrijo food industry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12331
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2021
EUROPÄISCHE NORM
ICS 67.260 Supersedes EN 12331:2015
English Version
Food processing machinery - Mincing machines - Safety
and hygiene requirements
Machines pour les produits alimentaires - Hachoirs - Nahrungsmittelmaschinen - Wölfe - Sicherheits- und
Prescriptions relatives à la sécurité et l'hygiène Hygieneanforderungen
This European Standard was approved by CEN on 23 May 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 12331:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 8
3 Terms and definitions . 9
4 Safety requirements and/or measures . 13
4.1 General . 13
4.2 Mechanical safety . 13
4.3 Electrical hazards . 27
4.4 Stability of the machine . 29
4.5 Noise reduction . 30
4.6 Hazards from use of gases (N2, CO2 and steam) . 31
4.7 Ergonomic requirements . 31
4.8 Hygiene and cleaning . 32
5 Verification of safety requirements and/or measures . 34
6 Information for use . 36
6.1 General . 36
6.2 Operating instructions . 36
6.3 Marking . 38
Annex A (normative) Noise test code for mincing machines (grade 2) . 40
A.1 Emission sound pressure level determination . 40
A.2 Determination of the sound power level . 40
A.3 Installation and mounting conditions . 40
A.4 Operating conditions . 40
A.5 Measurement . 41
A.6 Information to be recorded . 41
A.7 Information to be reported . 41
A.8 Measurement uncertainty . 42
A.9 Declaration and verification of the noise emission values . 42
Annex B (normative) Design principles to ensure cleanability of mincing machines . 44
B.1 Definition . 44
B.2 Materials . 44
B.3 Design . 44
Annex C (informative) Performance level required . 49
Annex D (informative) List of significant hazards . 50
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 51
Bibliography . 53

European foreword
This document (EN 12331:2021) has been prepared by Technical Committee CEN/TC 153 “Machinery
intended for use with foodstuffs and feed”, 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 February 2022 and conflicting national standards shall
be withdrawn at the latest by February 2022.
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.
This document supersedes EN 12331:2015.
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.
The significant changes with respect to the previous edition EN 12331:2015 are listed below:
— for better distinction, two types of mincing machines are defined: professional and industrial;
— the requirements have been specified and revised with regard to the two types of mincing machine
(professional and industrial).
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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.
Introduction
This document is a type-C-standard as stated in EN 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.).
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 the 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 machinery concerned and the extent to which hazards, hazardous situations and hazardous events
are covered are indicated in the scope of this document.
When provisions of this type-C-standard are different from those which are stated in type-A- or -B-
standards, the provisions of this type-C-standard take precedence over the provisions of the other
standards, for machines that have been designed and built according to the provisions of this type-C-
standard.
1 Scope
This document specifies requirements for the design and manufacture of mincing machines (see
Figure 1).
The mincing machines (hereinafter referred to as machine) covered by this document are used for size
reduction of fresh or frozen meat, meat products and fish (hereinafter referred to as product) by cutting
in a set of cutting tools.
Household machines are not included in this document. Filling mincers are covered by EN 12463 “Food
processing machinery — Filling machines and auxiliary machines — Safety and hygiene requirements”.
This document applies only to machines that are manufactured after the date of issue of this document.
This document covers:
a) professional machines (see Figure 1 a) used for on-demand preparation in shops and/or restaurants
characterized by all of the following features (if any of the features is missing the machine is
considered an industrial machine):
1) designed as a table-top machine;
2) having a feed tray;
3) the product is only fed manually;
4) is only operated from the ground;
5) is operated by no more than one operator;
6) with full visibility and full accessibility of the entire machine from the operator workstation;
7) having hole plate diameter ≤ 106 mm;
8) a worm casing set which is removable without using any tools;
9) the weight of the worm casing set ≤ 15 kg;
NOTE The table-top machine can be equipped with a frame or base, so no separate table is needed.
b) industrial machines (see Figure 1 b) used for industrial mass production, and which cannot be
characterized as a professional machine.
This document does not describe the specific requirements for the control of machines with foot switch.
This document does not describe the specific requirements for additional mixing screws in the feed intake
hopper which are covered by EN 13570:2005+A1:2010 “Food processing machinery — Mixing machines
— Safety and hygiene requirements”.
a) Professional machine with feed tray and b) Industrial machine with feed intake hopper,
restrictor plate protective cover and feeding screw
Key
1 lock nut 6 feed intake 11 feed intake hopper 16 protective hood
2 hole plate 7 pusher 12 feeding screw 17 worm
3 blade 8 restrictor plate 13 protective cover 18 machine rack
4 worm 9 feed tray 14 on-/off-switch with 19 loading device
protective hood
5 worm casing 10 on-/off-switch 15 lock nut 20 floor
21 table 22 table-top
Figure 1 — Examples of machines
This document covers the following types of machines:
— machine with feed tray, feed intake and pusher (see Figure 3);
— machine with feed tray, feed intake, restrictor plate and pusher (see Figure 4);
— machine with feed intake hopper, protective cover and feeding screw (see Figure 6);
— machine with feed intake hopper, with or without protective cover, feeding screw, with loading
device (continuously or discontinuously).
Machines comprise a machine base, a worm casing with a worm, a feed tray (with feed intake) or a feed
intake hopper, a set of cutting tools, a lock nut, a drive motor. They will also have various safeguarding
devices as examples in Clause 4.
Machines can be equipped e.g. with:
— an extraction claw;
— an ejector or extractor;
— a protective hood over the discharge outlet;
— a protective cover over the inlet opening of the feed intake hopper;
— a transport carriage for the lock nut, the set of cutting tools, the worm and the feeding screw;
— a lifting device for the lock nut, the set of cutting tools, the worm and the feeding screw;
— a loading device.
The product is fed manually or with a loading device into the machine. The product is fed to the worm
either by a pusher or a feeding screw and reduced in size by a set of cutting tools.
This document specifies all significant hazards, hazardous situations and events relevant to machines,
when they are used as intended and under conditions of misuse which are reasonably foreseeable by the
manufacturer (see Annex D).
This document specifies the hazards which can arise during commissioning, operation, cleaning, use,
maintenance and decommissioning of the machine.
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 614-1:2006+A1:2009, Safety of machinery — Ergonomic design principles — Part 1: Terminology and
general principles
EN 1005-1:2001+A1:2008, Safety of machinery — Human physical performance — Part 1: Terms and
definitions
EN 1005-2:2003+A1:2008, Safety of machinery — Human physical performance — Part 2: Manual
handling of machinery and component parts of machinery
EN 1005-3:2002+A1:2008, Safety of machinery — Human physical performance — Part 3: Recommended
force limits for machinery operation
EN 1672-2:2005+A1:2009, Food processing machinery — Basic concepts — Part 2: Hygiene requirements
EN 60204-1:2018, Safety of machinery — Electrical equipment of machines — Part 1: General
requirements (IEC 60204-1:2016, modified)
1)
EN 60529:1991 , Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)
EN 61496-1:2013, Safety of machinery — Electro-sensitive protective equipment — Part 1: General
requirements and tests (IEC 61496-1:2012)
EN ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise
sources using sound pressure — Engineering methods for an essentially free field over a reflecting plane
(ISO 3744:2010)
1) As impacted by EN 60529:1991/A1:2000 and EN 60529:1991/A2:2013.
EN ISO 3746:2010, Acoustics — Determination of sound power levels and sound energy levels of noise
sources using sound pressure — Survey method using an enveloping measurement surface over a reflecting
plane (ISO 3746:2010)
2)
EN ISO 4287:1998 , Geometrical product specifications (GPS) — Surface texture: Profile method — Terms,
definitions and surface texture parameters (ISO 4287:1997)
EN ISO 4871:2009, Acoustics — Declaration and verification of noise emission values of machinery and
equipment (ISO 4871:1996)
EN ISO 7010:2020, Graphical symbols — Safety colours and safety signs — Registered safety signs
(ISO 7010:2019, Corrected version 2020-06)
EN ISO 11201:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission
sound pressure levels at a work station and at other specified positions in an essentially free field over a
reflecting plane with negligible environmental corrections (ISO 11201:2010)
EN ISO 11202:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission
sound pressure levels at a workstation and at other specified positions applying approximate environmental
corrections (ISO 11202:2010)
EN ISO 11688-1:2009, Acoustics — Recommended practice for the design of low-noise machinery and
equipment — Part 1: Planning (ISO/TR 11688-1:1995)
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
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 13854:2019, Safety of machinery — Minimum gaps to avoid crushing of parts of the human body
(ISO 13854:2017)
EN ISO 13857:2019, Safety of machinery — Safety distances to prevent hazard zones being reached by
upper and lower limbs (ISO 13857:2019)
EN ISO 14119:2013, Safety of machinery — Interlocking devices associated with guards — Principles for
design and selection (ISO 14119:2013)
EN ISO 14120:2015, Safety of machinery — Guards — General requirements for the design and
construction of fixed and movable guards (ISO 14120:2015)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 12100:2010 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/

2) As impacted by EN ISO 4287:1998/AC:2008 and EN ISO 4287:1998/A1:2009.
3.1
platform
accessible workstation
3.2
worm
rotating screw-shaped component in the worm casing for product transport to the set of cutting tools
3.3
ejector/extractor
device for detaching the set of cutting tools and the worm
3.4
extraction claw
tool for detaching the set of cutting tools and the worm
3.5
loading device
device for the lifting and tilting of transport cars and containers
3.6
container
device for holding processed and/or unprocessed product
3.7
protective cover
device with safety function
3.8
feed intake
housing between the feed tray and the worm casing
3.9
feed intake hopper
device for holding the unprocessed product
3.10
locking device
device for locking the trolley or container in the load bearing device
3.11
trolley
movable container
3.12
design dimension
sum of dimensions measured as tight string length from the workstation (floor, steps, intermediate steps
or platforms) to the hopper edge (inclusively additional safety measures) and from the hopper edge
(inclusively additional safety measures) to the first danger point in the feed intake hopper (see Figure 7
and Figure 8)
3.13
cooling mincer
machine with a cooling device for the feed intake and the worm casing
3.14
workstation
every location at the machine from which the operator interacts with the machine
3.15
hole plate
plate with bores
Note 1 to entry: A hole plate is shown in Figure 1 a).
3.16
end hole plate
last hole plate towards the outlet
3.17
blade
element for cutting the product
3.18
feed tray
device for receiving the product to be processed to feed the feed intake by hand
3.19
mechanical trip bar
movable device with a safety function
3.20
worm casing
element for holding the worm and the set of cutting tools
3.21
worm casing set
arrangement consisting of a worm casing, a worm, a set of cutting tools and a lock nut
3.22
set of cutting tools
arrangement of blades and hole plates for size reduction of product
Note 1 to entry: The number and type of cutting tools used is selected depending on the desired quality of the
minced product.
3.23
protective grid
device on the feed intake hopper mouth with a safety function
3.24
protective hood
device on the discharge outlet with a safety function
3.25
restrictor plate
device above the feed intake
3.26
pusher
device used to push the product further in the feed intake
3.27
feeding screw
rotating screw-shaped component in the feed intake hopper for product transport to the worm
3.28
transport carriage
movable device for holding the lock nut, set of cutting tools, worm and feeding screw
3.29
lock nut
device for locking the set of cutting tools in the worm casing
3.30
professional machine
machine used for on-demand preparation in shops or restaurants
Note 1 to entry: A professional machines used for on-demand preparation in shops and/or restaurants is
characterized by all of the following features (if any of the features is missing the machine is considered an industrial
machine):
— designed as a table-top machine;
— having a feed tray;
— the product is only feed manually;
— is only operated from the ground;
— is operated by no more than one operator;
— with full visibility and full accessibility of the entire machine from the operator workstation;
— having hole plate diameter ≤ 106 mm;
— a worm casing set which is removable without using any tools;
— the weight of the worm casing set ≤ 15 kg.
Note 2 to entry: The table-top machine can be equipped with a frame or base, so no separate table is needed.
3.31
industrial machine
machine used for industrial mass production or which cannot be characterized as a professional machine
3.32
easily cleanable
designed and constructed to be cleanable by a simple cleaning methode, where necessary after removing
easily dismantled parts
4 Safety requirements and/or measures
4.1 General
Machinery shall comply with the safety requirements and/or protective measures of this clause. In
addition, the machine shall be designed according to the principles of EN ISO 12100:2010 for relevant,
but not significant hazards which are not dealt with by this document.
Where the means of reducing the risk is by the arrangement or positioning of the installed machine, the
manufacturer shall include in the Information for use a reference to the reduction means to be provided,
and to any limiting value of the requirement, and, if appropriate, to the means of verification.
Where the means of reducing the risk is by a safe system of work, the manufacturer shall include in the
information for use details of the system and of the elements of training required by the operating
personnel.
Machine safety functions are implemented and assured through Safety-Related Parts of the Control
System (SRP/CS) that shall achieve a required Performance Level (PL ). This requirement is given for
r
each safety function in the relevant subclauses of Clause 4. Table C.1 summarizes PL for each safety
r
function; however, the provisions of Clause 4 remain the sole and complete normative set of
requirements and explanations.
Figure 2 shows the significant hazard zones of machines.

a) Machine with feed intake b) Machine with feed intake hopper
Key
1 zone 1 4 zone 4 7 zone 7
2 zone 2 5 zone 5 8 zone 8
3 zone 3 6 zone 6 9 zone 9
10 zone 10
Figure 2 — Hazard zones
4.2 Mechanical safety
4.2.1 General
The machines shall be designed and constructed in accordance with the conditions mentioned below.
The interlocking systems of guards shall comply with EN ISO 14119:2013, 4.2, and the safety-related
parts of the control system shall comply with EN ISO 13849-1:2015.
In addition, interlocking systems shall be designed to comply with the following features:
— fulfil hygienic requirements;
— protected against mechanical damages;
— protected against the effects of cleaning and disinfecting materials;
— protected against the effects of cleaning fluids (water);
— not be easy to by-pass or render non-operational;
— be contained in the machine casing and comply with EN ISO 14119:2013, 7.2 a) 1).
The manufacturer shall indicate in the instruction handbook that the interlocking device shall be checked
every day (see 6.2 d)). Fixing systems of fixed guards shall remain attached to these guards or to the
machine when the guards are removed.
4.2.2 Zone 1 – Requirements for machines with feed intake and worm
Access to the worm in the feed intake shall be prevented, e.g. by the following measures:
1) On machines with diameter of feed intake D ≤ 52 mm (see Figure 3), the distance L between the upper
feed intake edge and the worm shall be:
a) L ≥ 100 mm on machines with diameter of feed intake D ≤ 46 mm;
b) L ≥ 120 mm on machines with diameter of feed intake 46 mm < D ≤ 52 mm.

a) Fixed feed tray b) Removable feed tray c) Removable feed tray
Key
D inlet diameter of feed intake
L distance from inlet of feed intake to worm
1 feed tray
2 feed intake
3 worm
Where the inlet is not a circle, D shall be considered as the maximum dimension.
Figure 3 — Feed intake without restrictor plate – Safety dimensions
2) On machines with a diameter of feed intake D > 52mm, a restrictor plate (see Figure 4) shall be
provided by the following measures:
a) the restrictor plate shall be provided with an interlocking device unless it is permanentally fixed
(e.g. by welding; a fixation by means of screws is not regarded as permanent);
b) when a force between the mass of the machine and ≤ 150 N is applied in any position and any
direction on the restrictor plate, the restrictor plate shall not permanentally raise the distance S
more than 2 mm if the requirements of Table 1 are met;
c) the inlet of the restrictor plate shall have a diameter C ≤ 52 mm;
d) the horizontal distance from outer edge of restrictor plate to feed intake edge shall be E ≥ 40 mm;
e) the dimensions S, L, L and L and the arrangement of the restrictor plate shall be in accordance
1 2
with Figure 4 and Table 1;
A pusher shall be supplied with the machine (see Figure 1 a)). The functional length of the pusher L shall
p
be 0,9 × (L + S) ≤ L < (L + S), and the diameter of the functional length C shall be 0,9 × C ≤ C < C and shall
p p p
have a mechanical stop with a dimension D ≥ 1,1 × C. Additionally, the handle shall have a shape and
p
dimensions that prevent from reaching the worm. The machine should be equipped with a holder for the
pusher, which will take the pusher during non-use.
The interlocking system of the removable feed tray or restrictor plate shall comply with 4.2.1 and the
safety-related parts of the control system shall present at least a Performance Level “d” defined with an
MTTF “high” according to EN ISO 13849-1:2015.
d
After removal of the feed tray or the restrictor plate the worm shall come to a standstill within 2 s, tested
on a machine which is running empty.
Table 1 — Safety dimensions on feed intake with restrictor plate
Dimension 52 mm < D ≤ 85 mm 85 mm < D ≤ 200 mm
C ≤ 52 mm
a
E ≥ 40 mm
S ≤ 40 mm ≤ 120 mm
L ≥ 120 mm L + L
1 2
L not applicable ≥ 230 mm
b
L not applicable to be calculated
a
Usually the restrictor plate is attached to the rim of the feed tray and reaches over the feed intake by at least E > 40 mm.
b
With a dimension S ≤ 40 mm, the hand can penetrate up to the wrist and the kinked fingers get into the feed intake, so
that the dimension L ≥ 120 mm prevents reaching the worm. From a dimension S > 40 mm, the forearm can also penetrate,
and the complete hand can get into the feed intake, considered by the dimension L ≥ 230 mm. To prevent reaching the
worm, however, dimension L is required. Here a dimension L2 shall be added to the dimension L1 as a function of the
intervention angle, which is determined by the dimensions E, S and D with an assumed forearm and wrist diameter
H = 40 mm.
a) 52 mm < D ≤ 85 mm b) 85 mm < D ≤ 200 mm
Key
penetration by hand, wrist, forearm

C inlet diameter of restrictor plate
D inlet diameter of feed intake
E horizontal distance from outer edge of restrictor plate to feed intake edge
H diameter of forearm and wrist
S distance between feed tray and lower edge of restrictor plate
L distance from inlet of feed intake to worm
L distance from wrist to worm
Figure 4 — Feed intake with restrictor plate – Safety dimensions
Key
L functional length of the pusher (0,9 × (L + S) ≤ L < (L + S))
p p
Cp diameter of the functional length (0,9 × C ≤ Cp < C)
Dp dimension of the mechanical stop (Dp ≥ 1,1 × C)
C inlet diameter of restrictor plate (see Figure 4)
S distance between feed tray and lower edge of restrictor plate (see Figure 4)
L distance from inlet of feed intake to worm (see Figure 4)
Figure 5 — Example of a pusher
4.2.3 Zone 2 – Requirements for machines with feed intake hopper and feeding screw
4.2.3.1 General
Access to the danger zones at the feeding screw in the feed intake hopper shall be prevented by one of
the following measures:
— the design (e.g. closed feed intake hoppers) including a closed loading device for products (e.g. feed
screw, pipeline with pump) (see 4.2.3.2);
— the use of guards (e.g. a protective cover) (see 4.2.3.3);
— the use of electro-sensitive protective devices (e.g. light barrier, see 4.2.3.5.3);
— the use of fixed guards (e.g. fence) (see 4.2.8.2.4);
— the use of adequate safety distances, design and additional measures (see 4.2.3.5).
4.2.3.2 Machines with closed feed intake hopper
The feed intake hopper and the loading device shall be designed to be completely closed (connection of
machines), or the openings shall comply with EN ISO 13857:2019, Table 4.
Where the loading device can be disconnected from the feed intake hopper, it shall be fitted with an
interlocking device complying with EN ISO 14119:2013 in a circuit that ensures that machine can only
run if the loading device is correctly fitted. This circuit shall comply with at least a Performance Level “c”
according to EN ISO 13849-1:2015.
The manufacturer shall indicate in the instruction handbook that the protective cover of the hopper
opening shall not be walked on (see 6.2 d)).
4.2.3.3 Machines with a protective cover over feed intake hopper
At the feed intake hopper, there shall be a protective cover. The protective cover shall be interlocked. The
slamming of the protective cover shall be avoided (see 4.2.7.1). Depending on the distance to the first
danger point E in the feed intake hopper, the feeding screw has to come to a standstill by the opening
distance H (see Figure 6) within 4 s (machine is running empty) after raising the front edge of the
protective cover.
The interlocking device of the movable protective cover shall comply with 4.2.1, and the safety-related
parts of the control system shall present at least a Performance Level “c” according to
EN ISO 13849-1:2015.
Openings in the protective cover shall be designed in accordance with EN ISO 13857:2019, Table 4.
Dimensions in millimetres
E H
≥ 100 ≤ 12
≥ 120 ≤ 20
≥ 200 ≤ 30
≥ 300 ≤ 40
≥ 550 ≤ 50
Key
H opening distance
E distance to the first danger point
Figure 6 — Machine with feed intake hopper and protective cover — Safety dimensions
4.2.3.4 Access to the feeding screw
Access to the feeding screw shall be prevented by an interlocking movable guard in accordance with
EN ISO 14120:2015 under one of the following conditions:
— the feeding screw shall come to a standstill within 2 s after activation of the protective device;
— dismantling of the guard takes longer than 4 s;
— interlocking guard with guard locking.
4.2.3.5 Machines with continuous operation
4.2.3.5.1 General
On machines which cannot use an interlocked protective cover or an electro-sensitive protective device
because they need to operate continuously, the following measures are necessary:
4.2.3.5.2 Safety distances
The design dimension (see 3.12) shall be ≥ 2 250 mm. This is only possible in connection with additional
measures in 4.2.3.5.3. There the distance from floor to upper edge of a mechanical trip bar or an electro-
sensitive protective device shall be H > 1 600 mm. The distance from the workstation on steps and
platforms up to the hopper edge shall be > 1 100 mm (see Figure 8).
4.2.3.5.3 Additional measures
With a height of > 1 500 mm, a view into the feed intake hopper (e.g. by means of a mirror, fill level
indication) shall be possible.
The machine shall be designed (e.g. vertical and smooth) to prevent the operator climbing on the
machine. This also applies to movable steps in its upper position and the surrounding of mechanical trip
bar/electro-sensitive protective device or movable protective grid at hopper edge.
Additional measures for:
a) steps or platforms
If danger points in the feed intake hopper can be reached from a workstation on step or platform (the
design dimension (see 3.12) does not reach 2 250 mm, see Figure 7) the step or platform shall be
interlocked. When the machine is running empty, the feeding screw shall come to a standstill within 4 s
after the interlocking system has been actuated. The actuation shall be triggered when an ascendable
position of a movable step is reached or the workstation on a step or platform is entered.
The interlocking system of the workstation on a step or platform shall comply with 4.2.1 and the safety-
related parts of the control system shall present at least a Performance Level “c” according to
EN ISO 13849-1:2015.
The workstation of steps shall have a width ≥ 500 mm and a length ≥ 400 mm and a toe rail of a height of
15 mm. If the workstation is < 500 mm above ground, an area of a width ≥ 400 mm and a length ≥ 350 mm
is sufficient. The workstation shall be of the non-slip type.
Platforms shall have an accessible area of a width ≥ 500 mm. The length of the platform shall correspond
to the length of the hopper.
Platforms which are located > 500 mm above ground shall be fitted with e.g. railings to prevent falls.
Intermediate steps, stairs or step ladders and grab handles shall be provided if the step-up height to the
step or to the platform is H > 500 mm. The workstations and treads shall be sufficiently large and of the
non-slip type and arranged at identical distances from one another.
The workstation of the intermediate step shall have a width of ≥ 300 mm and a length of ≥ 200 mm.
Treads of step ladders shall have a length of ≥ 500 mm and a width of ≥ 80 mm. A step ladder shall be
arranged at an angle of < 75° to the horizontal.
Key
1 mechanical trip bar
2 interlocked workstation (step)
H distance between floor and upper edge of safeguard when there is no workstation
H distance between interlocked workstation and upper edge of safeguard
H3 distance between floor and interlocked workstation
D width of safeguard when there is no workstation
D width of safeguard when there is a interlocked workstation
E distance between worm at S and upper edge of hopper when there is no workstation
E1 distance between worm at S1 and upper edge of hopper when there is a interlocked workstation
S1 distance between worm and hopper
S distance between and hopper and safeguard
H1 + D + E design dimension for a workstation on the floor ≥ 2 250 mm
Figure 7 — Machine with open feed intake hopper and interlocked workstation with mechanical
trip bar – Safety dimensions
b) Mechanical trip bar/Electro-sensitive protective device or movable protective grid at hopper edge.
At the hopper edge, running around all sides, shall be a mechanical trip bar, or an electro-sensitive
protective device, or a protective grid with a trip function (see Figure 7 and Figure 8). The design
dimension (see 3.12) shall be ≥ 2 250 mm.
The following requirements additionally apply depending on the safeguard selected:
— mechanical trip bar: the distance between the mechanical trip bar and the edge of the hopper shall
be S ≤ 50 mm and the mechanical trip bar shall be triggered within that range and the actuating
force shall be ≤ 50 N;
— electro-sensitive protective device:
— one beam light barrier: the distance between the one-beam light barrier and the edge of the
hopper shall be S ≤ 8 mm;
— all others: the distance between the electro-sensitive protective device and the edge of the
hopper shall be S ≤ 20 mm and the sensor detection capability of the electro-sensitive
protective device shall be ≤ 14 mm.
The dangerous equipment in the hopper shall, if the machines is running empty, come to a standstill
within 3 s by using hole plates < 160 mm Ø and 4 s by using hole plates ≥ 160 mm Ø.
The interlocking of the mechanical trip bar or the movable protective grid shall comply with 4.2.1, and
the safety-related parts of the control system shall present at least a Performance Level “c” according to
EN ISO 13849-1:2015.
The design of the light barrier shall be in accordance with ESPE type 2 of EN 61496-1:2013.

Key
1 light barrier or movable protective grid
2 workstation, not interlocked (step)
H1 ≥ 1 600 mm H4 ≥ 1 600 mm
H ≥ 1 100 mm H + D + E ≥ 2 250 mm
2 1
H ≥ 500 mm H + D + E ≥ 2 250 mm
3 4 1 1
H1 distance between floor and upper edge of safeguard when there is no workstation
D width of safeguard when there is no workstation
E distance between worm and upper edge of safeguard when there is no workstation
H2 distance between workstation (not interlocked) and upper edge of hopper
D1 width of safeguard when there is a workstation (not interlocked)
E1 distance between worm and upper edge of safeguard when there is a workstation (not interlocked)
H distance between workstation (not interlocked) and upper edge of safeguard
H3 distance between floor and workstation (not interlocked)
Design dimension for a workstation on the floor H1 + D + E
Design dimension for a workstation, not interlocked H + D + E
4 1 1
Figure 8 — Machine with open feed intake hopper and workstation (not interlocked) with
electro-sensitive protective device or protective grid – Safety dimensions
4.2.4 Zone 3 – Discharge outlet on machines
4.2.4.1 General
Access to the blade behind the end hole plate through the holes of the end hole plate shall be prevented,
e.g. by one of the following measures:
— the design of the end hole plate without protective hood (see 4.2.4.2);
— using a protective hood (see 4.2.4.3).
4.2.4.2 Design of the end hole plate without protective hood
The diameter of the holes in the end hole plate shall be ≤ 8 mm. The thickness of the end hole plate shall
be ≥ 5 mm.
The end hole plate and the worm casing shall be designed so that only a plate as described above can be
put into the worm casing at the outlet side.
The manufacturer has to indicate in the instruction handbook, that the end hole plate is not allowed to be
ground thinner than 5 mm thickness (see 6.2 d)).
4.2.4.3 Design of the protective hood
If it is intended to use end hole plates with holes > 8 mm diameter, a protective hood shall be fitted to the
outlet. The protective hood shall have a projecting length in working direction L ≥ 1,8 × D or L ≥ 550 mm
1 1
(D = diameter of the hole plate in mm) and a lateral projecting length of L ≥ 1,2 × D or L ≥ 300 mm.
2 2
Where L is the shortest distance from outer rim in front of the protective hood to the first danger point
at the end hole plate, and L is the shortest distance from outer rim at the side of the protective hood to
the first danger point at the end hole plate (see Figure 9).
The manufacturer has to indicate in the instruction handbook (see 6.2 d)), that the distance U between
the trolley, container or conveying system and the protective hood shall be ≤ 50 mm (see Figure 9). The
knife shall come to a standstill within 2 s after opening the protective hood by 50 mm at the point of
maximum movement. The protective hood shall be movable and interlocked.
Key
1 protective hood
2 end hole plate
3 locking nut
L1 ≥ 1,8 × D or ≥ 550 mm
L ≥ 1,2 × D or ≥ 300 mm
U ≤ 50 mm
Figure 9 — Discharge outlet on machines – Protective hood
The interlocking of the protective hood shall comply with 4.2.1 and
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