oSIST prEN 17735:2021

Commercial dishwashing machines - Hygiene requirement 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) fest. Es legt Anforderungen an die hygienischen Ergebnisse bei dem in Spülmaschinen behandelten Spülgut fest. Dies schließt auch einen Leitfaden für den hygienischen und ordnungsgemäßen Betrieb sowie für die Pflege und Wartung der Maschinen ein. Darüber hinaus werden Verfahren zum Prüfen eines hygienischen Betriebs festgelegt.
Spülmaschinen dienen in gewerblicher Umgebung zum Reinigen von Spülgut, das in Kontakt mit Lebensmitteln verwendet wird.
Dieses Dokument ist anzuwenden für Spülmaschinen zum Reinigen von Spülgut, das in Kontakt mit Lebensmitteln verwendet wird, wie z. B. Geschirr, Glaswaren, Besteck, Mehrwegtransportkästen und ähnliche Artikel.
Spülmaschinen (siehe 3.3) werden in Küchen wie z. B. in Restaurants, Kantinen, Krankenhäusern und in gewerblichen Betrieben wie z. B. Bäckereien, Fleischereien usw. verwendet.
Dieses Dokument ist nicht anzuwenden für Spülmaschinen für den Hausgebrauch, nicht für Reinigungs- und Desinfektionsgeräte zur Aufbereitung von Medizinprodukten und nicht für Maschinen für den industriellen Gebrauch (z. B. Maschinen zum Reinigen von Appretierblechen/ ablagen, Mehrwegflaschen, Vorrichtungen anderer Maschinen wie Fleischwolf, Aufschnittmaschine, Schneidemaschine, Teigteiler oder Kneter, Mischer, Rührer und andere Arten von Maschinen, von denen einzelne Teile durch standortfernes Waschen gereinigt werden könnten (en: washing out of place, WOP)).

Lave-vaisselles industriels - Exigences hygiéniques, essai

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). Il spécifie les exigences relatives aux résultats hygiéniques des articles traités dans les machines à laver la vaisselle. Cela inclut également le cadre directeur pour leur fonctionnement hygiénique et leur fonctionnement correct ainsi que pour l'entretien et la maintenance des machines. Des méthodes d’essai du fonctionnement hygiénique sont en outre définies.
Les machines à laver la vaisselle sont utilisées dans un environnement professionnel pour nettoyer les articles de vaisselle qui sont utilisés en contact avec les aliments.
Le présent document s'applique aux machines à laver la vaisselle destinées à nettoyer les articles de vaisselle qui sont utilisés en contact avec les aliments, comme les assiettes, la verrerie, les couverts, les boîtes réutilisables et les articles similaires.
Les machines à laver la vaisselle (voir 3.3) sont utilisées dans les cuisines, par exemple dans les restaurants, les cantines et les hôpitaux, ainsi que dans les entreprises commerciales telles 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 (par exemple les machines pour le nettoyage des plateaux d'étuvage, des bouteilles consignées, des équipements d'autres machines comme les hachoirs, les trancheurs, les découpeuses, les diviseurs de pâte ou les pétrisseuses, les mélangeurs, les agitateurs et tous les autres types de machines dont les pièces peuvent être nettoyées par lavage en place (WOP)).

Komercialni pomivalni stroji - Higienske zahteve in preskušanje

General Information

• Status: Not Published
• Public Enquiry End Date: 30-Nov-2021
• ICS: 97.040.40 - Dishwashers
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 08-Sep-2021
• Due Date: 26-Jan-2022
• Ref Project: prEN 17735 - Commercial dishwashing machines - Hygiene requirement and testing

Standards Content (sample)

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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oSIST prEN 17735:2021
prEN 17735:2021 (E)
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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oSIST prEN 17735:2021
prEN 17735:2021 (E)
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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oSIST prEN 17735:2021
prEN 17735:2021 (E)
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
reduction;
only 1 out of 8 shall
show a ≥ 4 log
reduction.
On test plates:
Minimum 90 % of
Type test
the
bioindicators shall
show a ≥ 5 log
reduction;
only 10 % shall
show a ≥ 4 log
reduction.
Bioindicators in the Bacterial All 10 bioindicators according to A.1.1
test rack reduction shall show a ≥ 5
log reduction.
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
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
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
Post-installation test Customised Machines after
— Temperature check
(arranged by the installation under practical
— Check of dosing/concentration of
operating company) conditions
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

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

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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oSIST prEN 17735:2021
prEN 17735:2021 (E)
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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oSIST prEN 17735:2021
prEN 17735:2021 (E)
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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