SIST EN 17735:2023
(Main)Commercial dishwashing machines - Hygiene requirements and testing
Commercial dishwashing machines - Hygiene requirements and testing
This document specifies hygiene requirements relating to the operation of commercial dishwashing machines (hereinafter referred to as dishwashing machines). It specifies requirements for hygienic results of the articles treated in the dishwashing machines. This includes also guidelines for their hygienic and proper operation and for care and maintenance of the machinery. Furthermore, methods for testing hygienic operation are defined.
Dishwashing machines are used in a professional environment for cleaning washware that is used in contact with food.
This document applies to dishwashing machines for cleaning washware that is used in contact with food, such as crockery, glassware, cutlery, reusable boxes and similar articles.
Dishwashing machines (see 3.3) are used in kitchens e.g. in restaurants, canteens and hospitals and in commercial enterprises such as bakeries, butcher's shops, etc.
This document does not apply to domestic dishwashing machines, washer disinfectors for the treatment of medical devices and machines for industrial use (e.g. machines for cleaning proofing trays, returnable bottles, equipment of other machines like mincer, slicer, cutter, dough dividers or kneader, mixers, stirrers and all other kind of machines from which parts could be cleaned by washing out of place (WOP)).
Gewerbliche Spülmaschinen - Hygieneanforderungen und Prüfung
Dieses Dokument legt Hygieneanforderungen an das Betreiben von gewerblichen Spülmaschinen (nachfolgend als Spülmaschinen bezeichnet) und an die Prüfungen, die an diesen Maschinen durchzuführen sind, fest. Es legt Anforderungen zum Erreichen eines angemessenen hygienischen Zustands des in Spülmaschinen behandelten Spülguts fest. Dieses Dokument enthält auch einen Leitfaden für den hygienischen und ordnungsgemäßen Betrieb, die Pflege und Wartung von Spülmaschinen. Darüber hinaus werden Verfahren zum Prüfen eines hygienischen Betriebs festgelegt.
Dieses Dokument ist anwendbar für Spülmaschinen, die in gewerblicher Umgebung zum Reinigen von Spülgut eingesetzt werden, das in Kontakt mit Lebensmitteln verwendet wird, wie z. B. Teller, Geschirr, Glaswaren, Besteck, Mehrwegbehälter und ähnliche Artikel.
Spülmaschinen werden in gewerblichen Küchen, wie z. B. in Restaurants, Kantinen, Krankenhäusern, und in Unternehmen, wie z. B. in Bäckereien und Fleischereien, verwendet.
Dieses Dokument ist nicht anwendbar für Spülmaschinen für den Hausgebrauch, nicht für Reinigungs- und Desinfektionsgeräte zur Aufbereitung von Medizinprodukten und nicht für Maschinen für den industriellen Gebrauch.
Machines à laver la vaisselle commerciales - Exigences liées à l'hygiène et essais
Le présent document spécifie les exigences en matière d’hygiène relatives au fonctionnement des machines à laver la vaisselle commerciales (ci-après dénommées machines à laver la vaisselle) et aux essais à réaliser sur ces machines. Il spécifie les exigences pour atteindre un état hygiénique approprié des articles traités dans les machines à laver la vaisselle. Le présent document inclut également des lignes directrices pour le fonctionnement hygiénique et adéquat, l’entretien et la maintenance des machines à laver la vaisselle. Des méthodes d’essai de fonctionnement hygiénique sont en outre définies.
Le présent document s’applique aux machines à laver la vaisselle utilisées dans un environnement professionnel, destinées à nettoyer les articles de vaisselle qui sont utilisés en contact avec les aliments, comme les assiettes, la vaisselle, la verrerie, les couverts, les boîtes réutilisables et les articles similaires.
Les machines à laver la vaisselle sont utilisées dans les cuisines professionnelles, par exemple dans les restaurants, les cantines et les hôpitaux, ainsi que dans les commerces, tels que les boulangeries, les boucheries, etc.
Le présent document ne s’applique pas aux lave-vaisselle domestiques, aux laveurs-désinfecteurs pour le traitement des dispositifs médicaux et aux machines à usage industriel.
Komercialni pomivalni stroji - Higienske zahteve in preskušanje
Ta dokument določa higienske zahteve v zvezi z delovanjem komercialnih pomivalnih strojev (v nadaljevanju: »pomivalni stroji«). Določa zahteve za higienske rezultate izdelkov, obdelanih v pomivalnem stroju. To vključuje tudi smernice za njihovo higiensko in pravilno delovanje ter nego in vzdrževanje. Opredeljene so tudi metode za preskušanje higienskega delovanja.
Pomivalni stroji se uporabljajo v profesionalnem okolju za čiščenje pribora, ki se uporablja v stiku z živili.
Ta dokument se uporablja za pomivalne stroje za čiščenje izdelkov, ki se uporabljajo v stiku z živili, kot so posoda, steklenina, jedilni pribor, škatle za večkratno uporabo in podobni izdelki.
Pomivalni stroji (glej točko 3.3) se na primer uporabljajo v kuhinjah restavracij, menz in bolnišnic ter v trgovskih podjetjih, kot so pekarne, mesnice itd.
Ta dokument se ne uporablja za gospodinjske pomivalne stroje, čistilno-dezinfekcijske naprave za obdelavo medicinskih pripomočkov in stroje za industrijsko uporabo (npr. stroje za čiščenje pladnjev za vzhajanje in povratnih steklenic, opremo drugih strojev, kot so mesoreznice, rezalniki, delilniki testa, gnetilniki ali mešalniki, ter vse druge vrste strojev, dele katerih bi bilo mogoče očistiti zunaj območja uporabe (WOP)).
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 17735:2023
01-marec-2023
Komercialni pomivalni stroji - Higienske zahteve in preskušanje
Commercial dishwashing machines - Hygiene requirements and testing
Gewerbliche Spülmaschinen - Hygieneanforderungen und Prüfung
Machines à laver la vaisselle commerciales - Exigences liées à l'hygiène et essais
Ta slovenski standard je istoveten z: EN 17735:2022
ICS:
97.040.40 Pomivalni stroji Dishwashers
SIST EN 17735:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 17735:2023
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SIST EN 17735:2023
EN 17735
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 97.040.40
English Version
Commercial dishwashing machines - Hygiene
requirements and testing
Machines à laver la vaisselle commerciales - Exigences Gewerbliche Spülmaschinen - Hygieneanforderungen
liées à l'hygiène et essais und Prüfung
This European Standard was approved by CEN on 14 November 2022.
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, Türkiye 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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17735:2022 E
worldwide for CEN national Members.
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SIST EN 17735:2023
EN 17735:2022 (E)
Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 10
4.1 Process requirements . 10
4.1.1 General. 10
4.1.2 Requirements for obtaining hygienic washing results . 10
4.2 Technical requirements . 12
4.2.1 Requirements relating to construction materials . 12
4.2.2 Functional requirements . 12
4.3 Requirements relating to the treating agents . 13
5 Testing . 13
5.1 General. 13
5.2 Type and scope of tests . 13
5.3 Test procedures . 14
5.3.1 Type test . 14
5.3.2 Post-installation test . 17
5.4 Overview of the number of samples for microbiological testing and the associated
record sheets . 18
Annex A (normative) Testing of hygienic operation of dishwashing machines – type test and
post-installation test . 19
A.1 Load. 19
A.1.1 Type testing . 19
A.1.2 Post-installation testing . 24
A.2 Microbiological test methods . 25
A.2.1 Determination of microbial reduction by bioindicators . 25
A.2.2 Aerobic colony count of wash ware surface . 28
A.2.3 Determination of the aerobic colony count of the detergent solution . 28
A.3 Reference detergent and rinse aid for the type test . 29
A.3.1 General. 29
A.3.2 Reference detergent . 29
A.3.3 Reference rinse aid . 30
A.4 Test report . 30
A.4.1 Documentation . 30
A.4.2 Data in the test report . 30
Annex B (informative) Technical recommendations onsite . 32
B.1 Functional requirements relating to the operation of dishwashing machines . 32
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SIST EN 17735:2023
EN 17735:2022 (E)
B.1.1 General . 32
B.1.2 Water quality. 32
B.1.3 Temperature . 33
B.1.4 Contact time . 33
B.1.5 Requirements relating to the treating agents . 34
B.2 Testing . 35
B.2.1 General . 35
B.2.2 Type of tests and scope of testing onsite . 35
B.2.3 Daily inspection . 36
B.2.4 Periodic inspection . 36
B.2.5 Overview of the number of samples for microbiological testing and the associated
record sheets . 36
Annex C (informative) Guideline for planning, organization of the dishwashing process,
maintenance and servicing of dishwashing machines and also relating to wash ware
. 37
C.1 Planning of dishwashing machine facilities . 37
C.2 Organization of the dishwashing process . 38
C.2.1 Operating personnel . 38
C.2.2 Receiving of used wash ware . 38
C.2.3 Pre-cleaning and loading of dishwashing machines . 38
C.2.4 Dishwashing machine programme cycle . 38
C.2.5 Drying and preparation and storage of the wash ware for further use . 39
C.3 Maintenance and servicing . 39
C.3.1 Operational and functional safety . 39
C.3.2 Operation logbook. 39
C.3.3 Cleaning of dishwashing machine . 39
C.4 Wash ware . 40
C.4.1 General . 40
C.4.2 Shape . 40
C.4.3 Surface characteristics . 40
C.4.4 Shape and surface of drinking glasses . 40
Annex D (informative) Examples record sheets . 41
D.1 Evaluation of the determination of the surface aerobic colony count . 41
D.2 Checking the aerobic microorganism count of the detergent solution . 41
D.3 Results of inspection with bioindicators . 42
Annex E (informative) Alternative Test Method . 45
Bibliography . 46
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SIST EN 17735:2023
EN 17735:2022 (E)
European foreword
This document (EN 17735:2022) has been prepared by Technical Committee CEN/TC 429 “Food hygiene
- Commercial warewashing machines - Hygiene requirements and testing”, 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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
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.
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 organisations 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, Türkiye and the United
Kingdom.
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SIST EN 17735:2023
EN 17735:2022 (E)
1 Scope
This document specifies hygiene requirements for the operation of commercial dishwashing machines
(hereinafter referred to as dishwashing machines) and the tests to be performed on these machines. It
specifies requirements for reaching an appropriate hygienic status of articles treated in the dishwashing
machines. This document also includes guidelines for the hygienic and proper operation, care and
maintenance of dishwashing machines. Furthermore, methods for testing hygienic operation are defined.
This document applies to dishwashing machines used in a professional environment for cleaning wash
ware that is used in contact with food, such as plates, crockery, glassware, cutlery, reusable boxes and
similar articles.
Dishwashing machines are used in professional kitchens, e.g. in restaurants, canteens and hospitals and
in businesses such as bakeries, butcher's shops, etc.
This document does not apply to domestic dishwashing machines, washer disinfectors for the treatment
of medical devices and machines for industrial use.
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 10088-3, Stainless steels — Part 3: Technical delivery conditions for semi-finished products, bars, rods,
wire, sections and bright products of corrosion resisting steels for general purposes
EN IEC 63136, Electric dishwashers for commercial use — Test methods for measuring the performance
(IEC 63136)
EN ISO 18593, Microbiology of the food chain — Horizontal methods for surface sampling (ISO 18593)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org/
3.1
wash ware
articles and utensils that come into contact with foodstuffs and re-usable crates/containers that are
cleaned in a dishwashing machine
Note 1 to entry: Examples of wash ware are plates, crockery, cutlery, glasses, kitchen utensils, pots, containers,
crates and trays made of materials such as porcelain, plastic, glass, stainless steel and silver as well as coated
materials.
3.2
re-usable container
wash ware that is used to store and transport unpacked easily perishable foods used in a professional
environment
Note 1 to entry: The container can be a crate.
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SIST EN 17735:2023
EN 17735:2022 (E)
3.3
wash ware carrier
device for holding and/or supporting wash ware in the optimum orientation for cleaning
Note 1 to entry: The wash ware carrier can be e.g. racks, conveyor belts, cutlery trays.
3.4
dishwashing machine
appliance that is specially designed for use in professional environments and that cleans and rinses
plates, glasses, cutlery, and, in some cases, cooking utensils by chemical, mechanical and thermal means
3.4.1
batch dishwashing machine
dishwashing machine, in which the wash ware carrier loaded with wash ware stays in the same treatment
zone during the cleaning process
Note 1 to entry: A distinction is made between the following machine designs:
— dishwashing machine in which recirculated detergent solution is used for the detergent circulation process
and fresh water is used for the fresh water rinsing; the fresh water rinsing circuit is separate from the detergent
circulation circuit;
— dishwashing machine in which fresh water is used in each detergent circulation or rinsing process; the rinsing
circuit is not necessarily separate from the detergent circulation circuit.
Note 2 to entry: Batch-type dishwashing machines can be loaded with one or more racks at the same time.
3.4.2
conveyor dishwashing machine
dishwashing machine in which the wash ware carriers loaded with wash ware are automatically
conveyed through the machine during the cleaning process
Note 1 to entry: A distinction is made between the following machine designs:
— rack conveyor dishwashing machine; dishwashing machine in which racks loaded with wash ware are
conveyed through the machine automatically by a rack transporting system;
— flight conveyor dishwashing machine; dishwashing machine in which the wash ware is conveyed through the
machine automatically on an endless conveyor.
Note 2 to entry: Conveyor type dishwashing machines can include different treatment zones. Zones are for
example prewash zone, detergent circulation zone and fresh water rinsing zone.
3.5
treating agent
product used to clean and/or sanitize and/or rinse and/or descale wash ware in dishwashing machines
Note 1 to entry: Examples of treating agents are: detergent, rinse aid and granules.
3.5.1
detergent
chemical product used to remove soil from wash ware and which prevents re-contamination of the wash
ware by soil in the detergent solution
Note 1 to entry: A detergent can also improve the sanitisation process.
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SIST EN 17735:2023
EN 17735:2022 (E)
3.5.2
detergent solution
water mixed with detergent used for the detergent circulation process
3.5.3
rinse aid
chemical product added to the water in the final rinsing operation which decreases the surface tension
of the rinse aid solution
Note 1 to entry: Rinse aid can also improve drying and reduce water spots on wash ware.
3.5.4
rinse aid solution
fresh water mixed with rinse aid used for fresh water rinsing
3.5.5
soaking agent
special detergent used in pre-soaking tanks outside the dishwashing machine to remove e.g. stubborn
soil from wash ware
3.5.6
descaling agent
chemical product used to remove lime-scale, mixed lime, calcium or magnesium phosphate deposits in
the dishwashing machine and on the wash ware
3.5.7
granules
particles, e.g. of plastic, which are added to the detergent solution to assist the mechanical cleaning effect
3.6
fresh water
untreated or treated water which, from the microbiological point of view, is of drinking water quality,
contains no substances that are harmful to health, and is used to supply the dishwashing machine
3.7
treated water
water which has been subjected to a treatment process to modify its ingredients
Note 1 to entry: A distinction is made between processes for softening the water and processes for reducing the
overall salt content
3.7.1
softened water
water from which the hardness ions or minerals have been removed in a water softener by cation
exchange processes without any reduction in the overall salt content
Note 1 to entry: The precipitation of water-insoluble salts is prevented.
3.7.2
demineralized water
water from which the salt content has been removed
Note 1 to entry: For example, by ion exchange or reverse osmosis processes.
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EN 17735:2022 (E)
3.8
pre-cleaning
removing loose scraps and food residues from the wash ware and emptying hollow vessels
Note 1 to entry: Pre-cleaning is normally carried out by wiping off the residues into waste containers and - if
possible - by rinsing the wash ware with warm water (max. 35 °C). Pre-cleaning reduces the amount of soiling
entering the dishwashing machine.
3.9
detergent circulation
process during which the detergent solution, which is kept heated to the nominal temperature, is
circulated and sprayed onto the surface of the wash ware to remove the soil
3.10
auxiliary rinsing
circulation rinsing upstream to fresh water rinsing, in which no detergent is dosed
3.11
fresh water rinsing
process after detergent circulation, during which the wash ware is sprayed with rinse aid solution in
order to remove residues of detergent solution, dissolved and undissolved soil particles
3.12
drying
process during which the moisture drips or evaporates from the surface of the wash ware
3.13
cleaning process
process including at least one detergent circulation process and one fresh-water rinsing process
3.14
sanitisation
chemical and/or physical process that reduces microorganisms to a level which is neither harmful to
health nor impairs the quality of foodstuffs
3.15
re-contamination
soiling of the wash ware between the end of the cleaning process and the preparation for further use
which causes deterioration of the cleaning result
3.16
contact time
time during which the detergent solution impacts the wash ware
Note 1 to entry: For conveyor-type machines the contact time commences from the centre of first prewash nozzle
and extends until the centre of the first fresh water rinse nozzle. For batch type dishwashing machines, the contact
time commences upon start of the detergent circulation and lasts until the start of the fresh water rinsing.
3.17
operating time
period during which the dishwashing machine is operational
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EN 17735:2022 (E)
3.18
spray system
sum of all pipelines, jets and spray pipes required to circulate and spray detergent and rinse aid solutions
3.19
interior
all parts of the dishwashing machine which come into contact with detergent solution, rinse aid solution
or the wash ware during the cleaning process as intended
3.20
exterior
all parts of the dishwashing machine which do not come into contact during the cleaning process with
detergent solution and rinse aid solution (e.g. pedestals, adjustable feet, handles, casing) but which are
accessible from outside
3.21
bioindicator
standardised test object meant to be contaminated with a test soiling media and a test microorganism
and is used to check the sanitisation performance of dishwashing machines
Note 1 to entry: Examples are stainless steel bioindicators.
3.22
operating company
company who actually uses the appliance to clean wash ware within its own activity
Note 1 to entry: Examples are the operators of restaurants or canteens.
3.23
hygiene requirement
condition of the wash ware which is neither harmful to health nor impairs the quality of foodstuffs
3.24
programme
series of operations that are pre-defined within the dishwashing machine and that are declared by the
manufacturer as suitable for cleaning certain wash ware
Note 1 to entry: Programme time, conveyer speed and temperatures are examples of main parameters which
define a programme.
Note 2 to entry: If there is no end of programme indicator, the programme time is equal to the cycle time.
3.25
cycle
complete cleaning process, as defined by the programme selected, consisting of a series of operations
(detergent circulation, fresh water rinsing, drying, etc.) and including any operations that occur after the
completion of the programme
Note 1 to entry: Examples of operations that can occur after the completion of the programme are refilling of the
boiler, heating, operation of pumps and fans.
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SIST EN 17735:2023
EN 17735:2022 (E)
4 Requirements
4.1 Process requirements
4.1.1 General
Each cleaning process as well as the resultant cleanliness and the hygienic condition of the wash ware
are determined by the interaction of several main factors:
— temperature of all process steps;
— contact time;
— treating agents;
— mechanics;
— design and interior shape of the wash ware;
— rinsing;
— drying.
4.1.2 Requirements for obtaining hygienic washing results
General requirements are:
a) The wash ware shall be visually clean under practical conditions at the customers' side.
b) The wash ware shall be dry upon removal from the wash ware carriers, with remaining droplets on
the supporting points and residual moisture in the interior of hollow articles being tolerated.
c) The machine shall lead, under test conditions (see 5.3.1.2), to a level of hygienic performance in
accordance with the requirements as specified in Table 1.
d) Treating agents used in the cleaning process shall be removed from the wash ware to a level that is
not harmful to health.
NOTE For further information see Annex B and Annex C.
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SIST EN 17735:2023
EN 17735:2022 (E)
Table 1 — Hygienic Performance
Microbiological requirements
Type of test Test object Criteria Requirement Test method
Bioindicators in the Bacterial In the cutlery tray: according to
cutlery tray, on test reduction A.2.1
Minimum 7 out of
plates
8 bioindicators shall
show a minimum
reduction of 5-log
a
levels ;
None of the
bioindicators shall
show a reduction
a
below 4-log levels .
On test plates:
Minimum 90 % of
the
Type test
bioindicators shall
show a minimum
reduction of 5-log
a
levels ;
None of the
bioindicators shall
show a reduction
a
below 4-log levels .
Bioindicators in the Bacterial All 10 bioindicators according to
test rack reduction shall show a A.2.1
minimum reduction
a
of 5-log levels .
b 2
Wash ware except Aerobic colony Contact plate
≤5 cfu per 10 cm
of re-usable count method
Post-
crates/containers according to
installation
made of plastic A.2.2
test
b
Detergent solution Aerobic colony according to
<500 cfu /ml
count A.2.3
a
Log levels are expressed as logarithms (base 10).
b
cfu: colony forming units.
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SIST EN 17735:2023
EN 17735:2022 (E)
4.2 Technical requirements
4.2.1 Requirements relating to construction materials
In terms of hygiene, the materials used shall be serviceable, scratch-proof, ageing-resistant and
corrosion-resistant under normal conditions of use. These conditions are:
— in the interior: contact with food remnants, detergents, disinfectants and rinse aids, descaling agent
solutions and hot air;
— on the exterior: contact with water, cleaning agents, disinfectants and care products.
4.2.2 Functional requirements
4.2.2.1 General
It shall be possible to place the wash ware easily into the wash ware carriers and the wash ware carriers
in the intended optimum position.
4.2.2.2 Temperature control
To ensure that the nominal temperature range has been reached, an indication (e.g. lamp, display
information) is required. Alternatively, the machine controls shall be designed so that the machine can
start operating only when the nominal temperature range is reached. In the intended range of
temperatures, the measurement instruments shall have an uncertainty of measurements of ± 3 K. This
can be temperature in tanks, zones, boilers.
The operation of a dishwashing machine requires a constant supply of energy. It is principally not
permissible to switch off heating elements tempora
...
SLOVENSKI STANDARD
oSIST prEN 17735:2021
01-november-2021
Komercialni pomivalni stroji - Higienske zahteve in preskušanje
Commercial dishwashing machines - Hygiene requirement and testing
Gewerbliche Spülmaschinen - Hygieneanforderungen und Prüfung
Lave-vaisselles industriels - Exigences hygiéniques, essai
Ta slovenski standard je istoveten z: prEN 17735
ICS:
97.040.40 Pomivalni stroji Dishwashers
oSIST prEN 17735:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 17735:2021
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oSIST prEN 17735:2021
DRAFT
EUROPEAN STANDARD
prEN 17735
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 97.040.40
English Version
Commercial dishwashing machines - Hygiene requirement
and testing
Lave-vaisselles industriels - Exigences hygiéniques, Gewerbliche Spülmaschinen - Hygieneanforderungen
essai und Prüfung
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 429.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17735:2021 E
worldwide for CEN national Members.
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Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Requirements . 9
4.1 Process requirements . 9
4.2 Technical requirements . 11
4.3 Requirements relating to the treating agents . 13
5 Testing . 13
5.1 General. 13
5.2 Types of test and scope of testing . 14
5.3 Test procedures . 14
5.4 Overview of the number of samples for microbiological testing and the associated record
sheets . 19
Annex A (normative) Testing of hygienic operation of dishwashing machines . 21
Annex B (informative) Technical recommendations onsite . 29
Annex C (informative) Guideline for planning, organization of the dishwashing process,
maintenance and servicing of dishwashing machines and also relating to washware . 34
Annex D (informative) Examples record sheets . 38
Annex E (informative) Alternative Test Method . 42
Bibliography . 43
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European foreword
This document (prEN 17735:2021) has been prepared by Technical Committee CEN/TC 429 “Food
hygiene — Commercial warewashing machines — Hygiene requirements and testing”, the secretariat of
which is held by DIN.
This document is currently submitted to the CEN Enquiry.
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1 Scope
This document specifies hygiene requirements relating to the operation of commercial dishwashing
machines (hereinafter referred to as dishwashing machines). It specifies requirements for hygienic
results of the articles treated in the dishwashing machines. This includes also guidelines for their hygienic
and proper operation and for care and maintenance of the machinery. Furthermore, methods for testing
hygienic operation are defined.
Dishwashing machines are used in a professional environment for cleaning washware that is used in
contact with food.
This document applies to dishwashing machines for cleaning washware that is used in contact with food,
such as crockery, glassware, cutlery, reusable boxes and similar articles.
Dishwashing machines (see 3.3) are used in kitchens e.g. in restaurants, canteens and hospitals and in
commercial enterprises such as bakeries, butcher's shops, etc.
This document does not apply to domestic dishwashing machines, washer disinfectors for the treatment
of medical devices and machines for industrial use (e.g. machines for cleaning proofing trays, returnable
bottles, equipment of other machines like mincer, slicer, cutter, dough dividers or kneader, mixers,
stirrers and all other kind of machines from which parts could be cleaned by washing out of place (WOP)).
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 10088-3, Stainless steels - Part 3: Technical delivery conditions for semi-finished products, bars, rods,
wire, sections and bright products of corrosion resisting steels for general purposes
EN IEC 63136, Electric dishwashers for commercial use - Test methods for measuring the performance
EN ISO 18593, Microbiology of the food chain - Horizontal methods for surface sampling (ISO 18593)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
washware
materials and utensils that come into contact with foodstuffs and re-usable crates/containers which are
cleaned in a dishwashing machine
Note 1 to entry: Examples of washware are crockery, plates, cutlery, kitchen equipment, glasses, pots, containers,
crates and trays made of materials such as porcelain, plastic, glass, stainless steel and silver as well as coated
materials.
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3.2
re-usable crates/containerstext of the definition
washware that is used for the storage and transport of unpackaged easily perishable foods used in a
professional environment
3.3
washware carrier
device for holding and/or supporting the washware in an optimum position during the cleaning
Note 1 to entry: The washware carrier can be e.g. racks, conveyor belts, cutlery trays.
3.4
dishwashing machine
electric dishwashing machine that is specially designed for use in professional environments and that
cleans and rinses plates, glasses, cutlery, and, in some cases, cooking utensils by chemical, mechanical
and thermal means
3.4.1
single-tank dishwashing machine
dishwashing machine with one detergent-circulating zone and a fresh water rinse either with a separate
fluid and nozzle system or as water-replacement machine
Note 1 to entry: The washware is cleaned using a detergent solution that is regenerated. The technical equipment
is geared to the performance that is required in the specific application. A distinction is made between the following
machine designs: manually-loaded batch dishwashing machine for one or two racks, flight-type dishwashing
machine and rack conveyor dishwashing machine.
3.4.1.1
batch dishwashing machine
dishwashing machine, in which the rack is inserted into the machine manually and in which the rack
loaded with washware stays during the complete cycle in the same treatment zone
3.4.1.2
single-tank flight-type dishwashing machine
single-tank dishwashing machine in which the washware is conveyed through the machine automatically
on an endless conveyor
3.4.1.3
single-tank rack conveyor dishwashing machine
single-tank dishwashing machine in which the racks loaded with washware are conveyed through the
machine automatically by a rack transporting system
3.4.1.4
granule dishwashing machine
single-tank dishwashing machine in which granules are used as a treating agent
3.4.1.5
water-replacement machine
single-tank dishwashing machine in which fresh water is used in each cleaning or rinsing phase and in
which the fresh water rinse is not implemented via a separate nozzle system
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3.4.2
multi-tank conveyor-type dishwashing machine
dishwashing machine comprising of more than one tank including various zones
Note 1 to entry: Zones are for example prewash zone, detergent circulating zone and fresh water rinsing zone.
3.4.2.1
multi-tank rack conveyor dishwashing machine
multi-tank dishwashing machine in which the racks loaded with washware are conveyed through the
machine automatically by a rack transporting system
3.4.2.2
multi-tank flight-type dishwashing machine
multi-tank dishwashing machine in which the washware is conveyed through the machine automatically
on an endless conveyor
3.4.3
glasswashing machine
dishwashing machine with one or more tanks including various zones for the treatment of glasses
3.5
treating agent
product used to clean and/or sanitize and / or rinse and / or descale washware in dishwashing machines
3.5.1
detergent
chemical product used to remove soiling from washware and which counteracts recontamination by
material in the detergent solution
Note 1 to entry: Additionally, a detergent can support the sanitization performance.
3.5.2
detergent solution
water mixed with detergent, which is used in the detergent circulating zone
3.5.3
rinse aid
chemical agent added to the water in the final rinsing operation which decreases the interfacial tension
of the rinse aid solution
Note 1 to entry: It improves the drying effect and reduces watermarks.
3.5.4
rinse aid solution
fresh water is mixed with rinse aid used for fresh water rinsing
3.5.5
soaking agent
special detergent used in pre-soaking tanks outside the dishwashing machine in order to remove e.g.
stubborn soiling from washware
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3.5.6
descaling agent
chemical product based on various acids and/or acid salts, which is used to remove lime-scale and/or
mixed lime and/or calcium and/or magnesium phosphate deposits in the dishwashing machine and on
the washware
3.5.7
granules
special particles, e.g. of plastic, which are added to the detergent solution in order to assist the mechanical
cleaning effect
3.6
fresh water
untreated or treated water which, from the microbiological point of view, is of drinking water quality,
contains no substances that are harmful to health, and is used to supply the dishwashing machine
3.7
treated water
water which has been subjected to a treatment process to modify its ingredients
Note 1 to entry: A distinction is made between processes for softening the water and processes for reducing the
overall salt content.
3.7.1
softened water
water from which the hardness ions/minerals have been removed by cation exchange processes in a
water softening plant without any reduction in the overall salt content
Note 1 to entry: The precipitation of water-insoluble salts is prevented.
3.7.2
demineralized water
water from which the salt content has been removed
Note 1 to entry: For example, by ion exchange or reverse osmosis processes.
3.8
pre-cleaning
removal of loose scraps and food residues from the washware and emptying of hollow vessels
Note 1 to entry: Pre-cleaning is normally carried out by wiping off the residues into waste containers and - if
possible - by rinsing the washware with warm water (max. 35 °C). Pre-cleaning reduces the amount of soiling
entering the dishwashing machine.
3.9
detergent circulation
process during which the detergent solution, which is kept heated to the nominal temperature, is
circulated and sprayed onto the surface of the washware for removal of soil
3.10
auxiliary rinsing
circulation rinsing connected upstream to fresh water rinsing, in which no detergent is dosed
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3.11
fresh water rinsing
process after detergent circulation, during which the washware is sprayed with rinse aid solution in order
to remove residues of detergent solution, dissolved and undissolved soil particles
3.12
drying
process during which the moisture drips or evaporates from the surface of the washware
3.13
cleaning process
process including at least one detergent circulation process and one fresh-water rinsing process
Note 1 to entry: In conveyor-type dishwashing machines, the cleaning process starts when the washware enters
the dishwashing machine and ends when it leaves the dishwashing machine.
3.14
sanitisation
chemical and/or physical process that reduces microorganisms to a level which is neither harmful to
health nor impairs the quality of foodstuffs
3.15
re-contamination
re-soiling of washware between the end of the warewashing process and preparation for further use,
which impairs the washing results
3.16
contact time
time during which the detergent solution impacts the washware
Note 1 to entry: For conveyor-type machines the contact time commences from the center of first prewash nozzle
and extends until the centre of the first fresh water rinse nozzle. For batch type dishwashing machines the contact
time commences upon start of the wash step until start of the fresh water rinse step.
3.17
operating time
period during which the dishwashing machine is operational
3.18
spray system
sum of all pipelines, jets and spray pipes required to circulate and spray detergent and rinse aid solutions
3.19
interior
all parts of the dishwashing machine which come into contact during the washing process with detergent
solution and rinse aid solution and/or the washware as intended
3.20
exterior
all parts of the dishwashing machine which do not come into contact with detergent solution and rinse
aid solution (e.g. pedestals, adjustable feet, handles, casing) during the washing process but which are
accessible from outside
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3.21
dirty side
area in which the soiled washware is received, pre-sorted, pre-cleaned and the dishwashing machine is
loaded
3.22
clean side
area of the washware cycle in which the clean washware is unloaded from the dishwashing machine and
prepared and stored for further use
3.23
bioindicator
standardized test object which has been contaminated with a standardised soil and test bacteria and is
used for checking the sanitization performance of dishwashing machines
Note 1 to entry: Examples are stainless steel bioindicators.
3.24
operating company
company who actually uses the appliance to clean washware within its own activity
Note 1 to entry: Examples are restaurants or canteens.
3.25
hygiene
condition of the washware which is neither harmful to health nor impairs the quality of foodstuffs
3.26
programme
series of operations that are pre-defined within the dishwashing machine and that are declared by the
manufacturer as suitable for cleaning certain washware
3.27
cycle
complete cleaning process, as defined by the programme selected, consisting of a series of operations
(washing, rinsing, drying, etc.) and including any operations that occur after the completion of the
programme
4 Requirements
4.1 Process requirements
4.1.1 General
Each cleaning process as well as the resultant cleanliness and the hygienic condition of the washware are
determined by the interaction of several main factors:
— temperature of all process steps;
— contact time;
— dosing of treating agents;
— mechanics;
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— design and interior shape;
— rinsing;
— drying.
The operating company shall be responsible for ensuring that the following parameters are effectively
taken into account and controlled since they significantly affect the resulting cleanliness and hygiene of
the washware:
— type and quantity of the introduced soil and length of time for which it has been allowed to dry on the
washware;
— shape, surface characteristics, design, degree of soiling and quantity of the washware;
— shape of the washware carrier and its loading;
— pre-cleaning;
— temperature;
— contact time;
— mechanics;
— rinsing;
— drying;
— water quality and volume;
— treating agents.
4.1.2 Requirements for obtaining hygienic washing results
General requirements are:
a) The washware shall be visually clean under practical conditions at the customers' side.
b) The washware shall be dry upon removal from the washware carriers, with remaining droplets on
the supporting points and residual moisture in the interior of hollow articles being tolerated.
c) The machine shall achieve a level of hygienic performance in accordance with the requirements as
specified in Table 1.
d) Treating agents used in the cleaning process shall be removed from the washware to a level that is
not harmful to health.
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Table 1 — Hygienic Performance
Microbiological requirements
Type of test Test object Criteria Requirement Test method
Bioindicators in the Bacterial In the cutlery tray: according to A.1.1
cutlery tray, on test reduction
Minimum 7 out of
plates
8 bioindicators shall
show a ≥ 5 log
10
reduction;
only 1 out of 8 shall
show a ≥ 4 log
10
reduction.
On test plates:
Minimum 90 % of
Type test
the
bioindicators shall
show a ≥ 5 log
10
reduction;
only 10 % shall
show a ≥ 4 log
10
reduction.
Bioindicators in the Bacterial All 10 bioindicators according to A.1.1
test rack reduction shall show a ≥ 5
log reduction.
10
a 2
Washware except of Aerobic Contact plate
≤5 cfu per 10 cm
re-usable microorganism method
crates/containers count according to A.1.2
Post-
made of plastic
installation
test
Detergent solution Aerobic <500 cfu/ml according to A.1.3
microorganism
count
a
cfu: colony forming units.
4.2 Technical requirements
4.2.1 Requirements relating to construction materials
In terms of hygiene, the materials used shall be serviceable, scratch-proof, ageing-resistant and
corrosion-resistant under normal conditions of use. These conditions are:
— in the interior: contact with food remnants, detergents, disinfectants and rinse aids, descaling agent
solutions and hot air;
— on the exterior: contact with water, cleaning agents, disinfectants and care products.
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4.2.2 Functional requirements relating to dishwashing machines
4.2.2.1 General
It shall be possible to place the washware easily and quickly into the washware carriers in the intended
optimum position. The washware and supporting devices, e.g. racks, conveyors, shall be aligned
accordingly.
4.2.2.2 Temperature control
To ensure that the nominal temperature range has been reached, an indicator (e.g. lamp) is required.
Alternatively the machine controls shall be designed so that the machine can operate only within the
predefined temperature range. Where relevant for hygiene requirements temperature indicating
instruments shall be provided. Temperature indicating instruments shall have an accuracy of ± 3 K.
NOTE This can be temperature in tanks, zones, boilers.
The operation of a dishwashing machine requires a constant supply of energy. It is principally not
permissible to switch off heating elements temporarily to avoid electrical peak loads (operation at partial
load) as this would involve a reduction of the temperature. If an energy optimization system is used, the
operator shall ensure that temperatures do not drop at any time, resulting in a possible hygiene risk.
Additional recommendations are given in Annex B.
4.2.2.3 Programme
Dishwashing machines usually have several programmes with different contact times.
At least one programme shall ensure that the requirements specified in 4.1.2 are fulfilled and it shall be
in accordance to 5.1.
4.2.2.4 Dosing
Correct dosing of the detergent and rinse aid into the detergent and rinse aid solutions shall be ensured
at any time.
NOTE Automatic dosing equipment is a good possibility for providing a correct dosing.
4.2.2.5 Design
Effective application of detergent and rinse aid solution to the washware shall be ensured.
All parts which have to be removed for cleaning (e.g. strainers and parts of the spray system) shall be
removable without use of tools and easily accessible. It shall be possible to take them out and put them
back to their correct position easily.
All areas to be cleaned shall be easy to maintain. Also removable parts shall be easy to clean.
NOTE Additional information is given in Annex C.
4.2.2.6 Rinsing
During the process the rinse aid solution shall access the washware fully and allow the formation of an
even rinsing solution/water film.
A sufficient quantity of rinse aid solution shall be assured for this purpose.
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4.2.2.7 Drying
Washware items which do not self-dry through their own intrinsic heat (e.g. process temperature) may
have to be dried using suitably hygienic measures prior to storage. Dishwashing machines may provide
means to improve the drying results.
4.2.2.8 Water quality
The incoming fresh water to the machine should fulfil the manufactures' recommendation.
4.3 Requirements relating to the treating agents
If treating agents are used they shall be used according to the manufacturers' instructions.
NOTE Additional information is given in the Annex B.
5 Testing
5.1 General
The commercial dishwashing machine manufacturer’s instructions regarding installation and use shall
be followed, except if they stand in conflict. In this case, this document shall prevail.
Before commencing measurements, the dishwashing machine shall be checked to ensure that it is
operating properly.
If the dishwashing machine is fitted with an integrated water softening unit, it shall be deactivated (set
to soft water supply). During testing, soft water with a water hardness of < 3°dH, or a total hardness of
2+ 2+
(Ca + Mg ) < 0,54 mmol/l, shall be used.
The programme/conveyor speed to be tested shall be the one declared by the manufacturer, which cleans
normally soiled washware.
For dishwashing machines included in the scope of EN IEC 63136, the programme to be tested shall be
the one that is used in performance test according to EN IEC 63136.
In order to check that dishwashing machines are operating hygienically, the following types of test, which
differ in scope, are distinguished for different purposes:
Types of test:
— type test;
— post-installation test.
NOTE Type of tests and scope of testing methods to be arranged by the operating company: see Annex B,
Table B.2.
Test methods/checks:
— visual inspection of cleanliness and dryness;
— temperature check;
— determination of the aerobic microorganism count of the washware surface;
— tests with bioindicators;
— microbiological testing of the detergent solution;
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— water quality check;
— additional test method is under consideration (see Annex E).
5.2 Types of test and scope of testing
The individual types of test and the scope of testing can be found in Table 2.
Table 2 — Types of test and scope of testing
Type of test Area of application Test Methods/checks
a
Type test (arranged by Machines in series
— Temperature check
manufacturer) production
— Check of dosing/concentration of
treating agents
— Tests with bioindicators
— Visual inspection of dryness of plates
a
Post-installation test Customised Machines after
— Temperature check
(arranged by the installation under practical
— Check of dosing/concentration of
operating company) conditions
a
treating agents
— Water quality check
— Determination of the aerobic
microorganism count of the washware
surface
— Microbiological testing of the detergent
solution
— Visual inspection of cleanliness and
dryness of plates
a
According to information/specification given by the manufacturer of the machine and/or the treating agents.
5.3 Test procedures
5.3.1 Type test
5.3.1.1 General
The type test is carried out with the appropriate bioindicators depending on the main use of the
1
dishwashing machine .
5.3.1.2 Dishwashing machines used primarily for washing plates, crockery and cutlery
5.3.1.2.1 General
The type testing comprises testing of the sanitisation performance with defined bioindicators
(contaminated stainless steel bioindicator, see A.1.1.4) which can be attached to plates measuring 24 cm
in diameter (hereinafter referred to as test plates) (see Figure 1) or used in cutlery trays.
Alternatively, for conveyor-type dishwashing machines a test rack according to Figure 4 can be used.
1 The method described below deals with a test method for commercial dishwashing machines used primarily
for washing plates and cutlery. As future projects it is planned to develop test methods for commercial dishwashing
machines used primarily for washing glasses or re-usable crates and containers.
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5.3.1.2.2 Procedure with test racks
Fill the relevant plate rack completely.
The racks shall be filled in accordance with the operating instructions. The test plates shall be numbered
for the evaluation. The position diagram (see D.3.2.1) shall be extended accordingly if more than two
plates can be placed next to each other in a rack, and/or if there are more than six rows in the rack.
Attach the bioindicators to the test plates using holders (see Figure 1). The contaminated side of the
bioindicator shall face upward.
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Figure 1 —Holder for test plates
Figure 2 — Test plate with bioindicator on holder attached
Use the test detergent (see A.2.2.1) in a solution with a mass concentration of 3 g/l ± 0,3 g/l. The dosi
...
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