hygienic design guidelines

ISHIDA EUROPE LIMITED

ENGINEERING HYGIENIC DESIGN GUIDE

[Hygienic design guide issue 1] | nr01

FOREWORD

This guidance identifies criteria for design, construction and installation detail conducive to hygienic operation in food processing factories. It sets out design practices that avoid hygienic problems in service, and provides a reference against which the food manufacturer may evaluate equipment and specify requirements in future proposals.

ContentsFOREWORD.........................................................................................................................................................2

1.0 SCOPE............................................................................................................................................................8

2.0 DEFINITIONS..................................................................................................................................................9

3.0 ESSENTIAL SAFETY REQUIREMENTS OF THE MACHINERY DIRECTIVE FOR CERTAIN CATEGORIES OF MACHINERY.......................................................................................................................................................13

3.1 Agri-foodstuffs Machinery.......................................................................................................................13

3.2 Instructions..............................................................................................................................................13

4.0 GENERAL HYGIENIC DESIGN PRINCIPLES.....................................................................................................14

4.1 General....................................................................................................................................................14

4.2 References and Further Reading.............................................................................................................15

5.0 VERIFICATION OF HYGIENIC REQUIREMENTS AND/OR MEASURES.............................................................17

6.0 INSTRUCTIONS FOR USE..............................................................................................................................18

7.0 EQUIPMENT GUIDELINES.............................................................................................................................19

7.1 CONVEYORS, ELEVATORS AND HANDLING..............................................................................................19

7.1.1 Belt Conveyors......................................................................................................................................19

7.1.1.1 Hazards..........................................................................................................................................19

7.1.1.2 Design Considerations...................................................................................................................19

7.1.1.3 Methods of Construction...............................................................................................................20

7.1.1.4 Materials of Construction..............................................................................................................20

7.1.1.5 Surface Finish.................................................................................................................................21

7.1.1.6 References and Further Reading...................................................................................................21

7.1.2 Bucket Conveyors.................................................................................................................................21

7.1.2.1 Hazards..........................................................................................................................................21


7.1.2.4 Method of Construction................................................................................................................22


7.1.2.4 Surface Finish.................................................................................................................................22


7.1.3 Vacuum Conveyors...............................................................................................................................23

7.1.3.1 Hazards..........................................................................................................................................23



7.1.3.3 Surface Finish.................................................................................................................................23


7.14 Screw Conveyors...................................................................................................................................24

7.1.4.1 Hazards..............................................................................................................................................24




7.1.4.6 Surface Finish.................................................................................................................................25


7.1.5 Chain Conveyors...................................................................................................................................25

7.1.5.1 Hazards..........................................................................................................................................25




7.1.5.5 Surface Finish.................................................................................................................................26


7.1.6 Slat Band/Wire Mesh Conveyors..........................................................................................................26

7.1.6.1 Hazards..........................................................................................................................................26




7.1.6.5 Surface Finish.................................................................................................................................28


7.1.7 Vibratory Conveyors.............................................................................................................................28

7.1.7.1 Hazards..........................................................................................................................................28




7.1.7.4 Surface Finish.................................................................................................................................29

7.17.5 References and Further Reading....................................................................................................29

7.1.8.1 Hazards..........................................................................................................................................29




7.1.8.4 Surface Finish.................................................................................................................................30


7.2 MULTIHEAD WEIGHERS...........................................................................................................................31

7.2.1 Description of Equipment and Definition.............................................................................................31

7.2.2 Hazards.................................................................................................................................................32

7.2.3 Design Considerations..........................................................................................................................32

7.2.4 Method of Construction.......................................................................................................................33

7.2.4.1 Inlet Chute.....................................................................................................................................33

7.2.4.2 Centre Cone...................................................................................................................................33

7.2.4.3 Radial Feeders...............................................................................................................................34

7.3.4.4 Hoppers.........................................................................................................................................34

7.2.4.5 Discharge Chute.............................................................................................................................34

7.2.5 Materials of Construction.....................................................................................................................34

7.2.7 Surface Finish.......................................................................................................................................35

7.2.7 References and Further Reading..........................................................................................................35

7.3 DEPOSITORS............................................................................................................................................35

7.3.1 Description of Equipment.....................................................................................................................35

7.3.2 Hazards.................................................................................................................................................36


7.3.4 Methods of Construction......................................................................................................................37

7.3.5 Materials of Construction.....................................................................................................................37

7.3.6 Surface Finish.......................................................................................................................................38

7.3.6 References and Further Reading..........................................................................................................38

8.0 COMPONENT GUIDELINES.......................................................................................................................39

8.1 FRAMEWORKS.........................................................................................................................................39

8.1.1 Hazards.................................................................................................................................................39


8.1.3 Method of Construction.......................................................................................................................40

8.1.4 Materials of Construction.................................................................................................................41

8.4.5 Surface Finish....................................................................................................................................41

8.1.6 References and Further Reading......................................................................................................41

8.2 HOPPERS AND CHUTES............................................................................................................................41

8.2.1 Hazards.............................................................................................................................................41

8.2.2 Design Considerations......................................................................................................................41

8.2.3 Construction Method.......................................................................................................................42


8.2.4 Surface Finish....................................................................................................................................43


8.3 WALKWAYS, HANDRAILS, STEPS AND STAIRS OVER CONVEYORS...........................................................43

8.3.1 Hazards.............................................................................................................................................43




8.3.5 Surface Finish....................................................................................................................................45


8.4 GUARDS, COVERS, PANELS AND CLADDING............................................................................................45

8.4.1 Hazards.............................................................................................................................................45




8.4.5 Surface Finish....................................................................................................................................47


9.0 Hygienic risk assessment.............................................................................................................................48

9.1 General....................................................................................................................................................48

10.0 Verification of Hygiene requirements........................................................................................................50

11.0 Annex A.....................................................................................................................................................52

11.1 Informative diagrams............................................................................................................................52

11.2 Supporting Photographs........................................................................................................................72

1.0 SCOPE

The document is intended for use by food manufacturers and food equipment manufacturers as a guide to good hygienic design practice for equipment used in the production of chilled prepared food. It highlights poor design and aims to promote an awareness of good design practices that will reduce hygiene problems inherent in equipment. The guidance serves as a means of evaluating 'food quality' equipment and its suitability for use in high risk areas. General hygienic design requirements for food products equipment are given in EN 1672-2.2009

This guidance is intended to assist equipment manufacturers in:

(a) Identifying the level of hygienic design appropriate for the product as defined by a HACCP study

(b) Designing a safe system for manufacturing and packing the product (c) Determining appropriate contact materials (d) Drafting appropriate cleaning and disinfecting procedures for the instructions for use

Equipment manufacturers shall ensure that all equipment is assessed against these requirements by competent persons.

Any limitations of use for specific equipment items shall be clearly stated in the instructions for their use. For example, “This machine has been designed to pack pre-packed low-risk foodstuffs”.

The features described in these guidelines have been found by experience to be beneficial to product hygiene in guarding against contamination by:

• Bacteriological build-up • Infestation of insects and pests • Foreign bodies from the environment of the equipment • Ingredients and raw materials

The principles are designated as a minimum acceptable standard and not intended to direct or restrict the main design purpose of equipment, but rather to ensure that the main purpose is carried out with full consideration for hygienic operation. Hence, the principles concern all aspects of equipment as built, covering incidental design, construction and installation, but excluding mandatory regulations and legislative issues including health and safety requirements as covered by UK and International law, which are taken as read (see section 3).

2.0 DEFINITIONS

Adverse influence

An effect which gives a significant reduction of the fitness for consumption of a food, A food can be adversely influenced by microbial pathogens or other unwanted microorganisms, toxins, vermin, domestic animals and other contaminants.

Areas of equipment:

• Food area

Area composed of surfaces in contact with food; the food area also includes the surfaces with which the product may come into contact under intended conditions of use, after which it returns to the product.

• Splash area

Area composed of surfaces on which part of the food may splash or flow along under intended conditions of use and does not return to the product.

• Non food area

Any area other than those specified above.

Cleaning in Place (CIP)

Removal of physical matter without the need to dismantle the machine.

Cleaning

Removal of physical matter from surfaces by physical and/or chemical means.

Cleanable

Designed and constructed so that physical matter is removed by recommended cleaning methods.

Contamination

The introduction or occurrence of a contaminant in a food product, ingredient or environment.

Contaminant

Physical matter, microorganisms, toxins or chemicals that may compromise food safety.

Corrosion resistant material

Material resistant to normally occurring action of chemical or electrochemical nature. It includes food processing, cleaning and disinfection according to the instructions for use.

Crevice

A surface defect e.g. crack, fissure, which adversely affects cleanability.

Dead Space

Space wherein a product, ingredient, cleaning or disinfecting agents or soils may be trapped retained or not completely removed during operation of cleaning.

Decontamination

Removal or reduction of contaminant(s) to an acceptable level for safety or quality.

Depositor

A machine dispensing a predetermined quantity of a product by volume and/or weight.

Disinfection

Microbiological decontamination.

Design Principles

A set of rules and concepts directed at equipment construction and installation associated with conveyors and general mechanical handling equipment found within high risk and low risk areas. End of line packaging equipment may, by its very nature, not be subject to this specification.

Prior to the design and construction of any equipment, a full HACCP evaluation should be undertaken for all equipment.

Durable

Ability of a surface to withstand the intended conditions of use, for example: to resist damage caused by the action of the process, contact with the food being processed, thermal actions, handling and contact with any cleaning or disinfecting agents specified.

Food

Any product, ingredient or material intended to be orally consumed.

Food Hygiene

Taking all of the measures during the preparation and processing of food to ensure that it is fit for human consumption.

Food Processing Equipment

All plant and machinery that comes into direct contact with food products or ingredients used by the processor in the treatment or handling of food.

Hazard Analysis Critical Control Point (HACCP)

A system that identifies specific hazard(s) and preventative measures for their control (see Appendix B of CFA’s Guidelines for Good Hygienic Practice in the Manufacture of Chilled Foods).

Joint

Junction of two or more pieces of material.

Non-absorbent material

Material which, under intended conditions of use, does not retain substances with which it comes into contact so that it has no adverse influence on food.

Non-toxic material

Material that does not produce or release substances injurious to health under intended conditions of use.

Product Contact Surfaces

All surfaces that ingredients may touch, condense onto, splash against and flow back from, including utensils.

Product Processing Areas

That space within food processing equipment which food products or ingredients have direct contact with during processing.

Seal

The closing of an aperture so as to effectively prevent the unwanted entry or passage of any matter.

Self-draining

Design and construction of the shape and surface finish so as to prevent liquid from being retained.

Smooth

Condition of a surface that satisfies operational and hygienic requirements.

Soil

Any unwanted matter, including product residues, micro-organisms, residual detergent or disinfecting agents.

Vermin

Animals (including mammals, birds, reptiles and insects) that may adversely influence the food.

3.0 ESSENTIAL SAFETY REQUIREMENTS OF THE MACHINERY DIRECTIVE FOR CERTAIN CATEGORIES OF MACHINERY

3.1 Agri-foodstuffs Machinery

Where machinery is intended to prepare and process foodstuffs (e.g. cooking, refrigeration, thawing, washing, handling, packaging, storage, transport or distribution), it must be so designed and constructed as to avoid any risk of infection, or contagion and the following hygiene rules must be observed:

a) Materials in contact, or intended to come into contact, with the foodstuffs must satisfy the conditions set down in the relevant Directives. The machinery must be so designed and constructed that these materials can be cleaned before each use;

b) All surfaces including their joinings must be smooth, and must have neither ridges nor crevices which could harbour organic materials;

c) Assemblies must be designed in such a way as to reduce projections, edges and recesses to a minimum. They should preferably be made by welding or continuous bonding. Screws, screwheads and rivets may not be used except where technically unavoidable;

d) All surfaces in contact with the foodstuffs must be easily cleaned and disinfected, where possible after removing easily dismantled parts. The inside surfaces must have curves of a radius sufficient to allow thorough cleaning;

e) Liquid deriving from foodstuffs as well as cleaning, disinfecting and rinsing fluids should be able to be discharged from the machine without impediment (possible in a 'clean` position);

f) Machinery must be designed and constructed as to prevent any liquids, organic matter or living creature (including insects), entering or accumulating in areas that cannot be cleaned (e.g. for machinery not mounted on feet or casters, by placing a seal between the machinery and its base, by the use of sealed units, etc.);

g) Machinery must be so designed and constructed that no ancillary substances (e.g. lubricants, etc.) can come into contact with foodstuffs. Where necessary, machinery must be designed and constructed so that continuing compliance with this requirement can be checked.

3.2 Instructions

In addition to the information required in section 1, the instructions must indicate recommended products and methods for cleaning, disinfecting and rinsing (not only for easily accessible areas but also where areas to which access is impossible or unadvisable, such as piping, have to be cleaned in situ).

4.0 GENERAL HYGIENIC DESIGN PRINCIPLES

Good hygienic design practices indicate the approach to be taken to reduce risks of product contamination arising from equipment operation. They seek to inhibit the opportunity for microbial build-up and prevent the introduction of non-ingredients material. This is achieved by promoting design features which:-

a) Minimise the possibility of product stagnation in the product area and reduce the possibility of spillage and soiling outside the equipment,

b) Allow and assist thorough cleaning and disinfecting of product contact surfaces and all external parts of the equipment.

c) Prevent material or parts from the equipment entering or affecting the product. d) Prevent external foreign matter entering the product areas.

Good hygienic design should take into account HACCP and full process considerations in order to ensure that potential hazards are identified and design measures put in place to ensure the suitability of equipment for the particular purpose to which it is to be put, minimising potential negative impact on the final product.

4.1 GeneralThe general principles apply to overall systems as well as to independent items of equipment. In subsequent sections of the guidelines, the principles are extended in the detailed application to various classifications, e.g. framework, welding etc. Most mechanical handling equipment has design elements referred to in the guidelines.

• Equipment materials in contact with the product must be Food and Drug Administration (FDA) approved and conform to The Materials and Articles in Contact with Food Regulations 1987, as amended.

• All contact surfaces must be inert to food products

• All surfaces must be safely accessible for cleaning and for visual examination as manual cleaning is carried out.

• Product contact surfaces must be smooth, seamless and scratch free.

• Products must move through the processing areas completely and with no temporary retention. The design should be for streamlined flow over product contact surfaces. This is particularly applicable to conveyors within cooling baths and Souse Vide systems.

• Spillage of food materials is not acceptable. The system design must minimise all possibility of spillage and provide hygienic methods of coping with instances where spilling, splashing, blowing or other leakage may occur.

• The design should be as simple as possible. This may be achieved by using fewer parts but of heavier design.

• The design must be kept as open as possible, avoiding corners that are difficult to reach.

• There should be no seams, gaps, crevices or any inaccessible recesses that are difficult to clean even on exterior non-contact surfaces. Ledges or horizontal surfaces must be avoided, particularly where difficult to clean. Contour such surfaces to ensure drainage.

• The hose-down procedure should anticipate any heavy run-off so as not to pass over cleaner parts. Ensure that run-off from external surfaces never flows across product contact surfaces.

• The system design must allow good housekeeping practices.

• Where appropriate, the system should demarcate boundaries, e.g. between high and low risk areas.

• Small detachable parts of machines should be properly secured. The use of Nyloc nuts or Aero self-locking nuts is recommended.

• Parts of the equipment where product is open to the atmosphere should be covered to prevent foreign matter falling into the product area.

• Equipment should be free-draining inside and out to the atmosphere, and should have no stagnant regions.

• All equipment must be designed to withstand alkaline washing solutions and hosing where HACCP demands.

• As much fabrication as practicable should be carried out off-site under clean workshop conditions.

4.2 References and Further Reading

BS EN ISO 12100-1: 2003 +A1: 2009 Safety of machinery - Basic concepts, general principles for design.

Part 1: Basic terminology, methodology

BS EN ISO 12100-1: 2003 +A1: 2009 Safety of machinery - Basic concepts, general principles for design.

Part 2: Technical principles and specifications

EN 1672-2: 2009 Food processing machinery - Basic concepts. Part 2: HygieneRequirements. 1997. CEN publication.

EN 60529: 1991 Specification for degrees of protection provided by enclosures (IP code)'Hygienic Design: International Issues', J Hookah. Dairy Food Env Sanit, 1998, 18 (4), 212-220.

8

'Hygienic Design Handbook', Second edition, May 1996, APV, UK

'Hygienic Design of Food Plant: A Guide to Good Hygienic Practice with Particular Reference to the Design of Tanks, Pumps and Pipe work', Food Manufacturers Federation, 1966

'A Practical Guide to the Disinfection of Food Processing Factories and Equipment Using Fogging', Silsoe Research Institute, 1998

‘Buying new machinery’, INDG270, HSE Books, 1998, ISBN 0 7176 1559 6

‘Effective purchasing procedures for equipment in the food and drink industries’, INDG323, HSE Books, 2000.

‘The Supply of Machinery (Safety) Regulations’. SI No. 3073, as amended. The Stationery Office, UK. 1992

EC Directives on food contact materials: implemented in the UK by The Materials and Articles in Contact with Food Regulations 1987 (SI 1523), as amended.

5.0 VERIFICATION OF HYGIENIC REQUIREMENTS AND/OR MEASURES Information taken from Table 1 EN 1672-2: 2009

Table 1

Requirement Verification

Durable Material specification (food, process and cleaningSpecification, etc.) and/or practical functional test.

Cleanable and/or capable of Visual inspection (drawing(s); on machinery) and/orbeing disinfected practical test, microbiological test or functional

Test.

Corrosion resistant Material specification (food, process and cleaningSpecification, etc.) and/or practical functional test.

Non toxic Material specification or practical test for materials

and articles intended to come into contact withfood.

Non absorbent Material specification or practical test for materialsand articles intended to come into contact withfood.

Not transfer undesirable odours, Material specification or practical test for materialscolours or taint to the food and articles intended to come into contact with

food.

Not contribute either to the Material specification or practical test for materials

contamination of food or have and articles intended to come into contact withany adverse influence on the food.food.

Surface design Visual inspection (Drawing(s) on machinery)

Surface finish Measuring according to ISO468

Permanent joints Visual inspection

Dismountable joints Visual inspection

Fasteners Visual inspection

Drainage Visual inspection (Drawing(s) on machinery) andpractical tests

Internal angles and corners Measurements

Dead spaces Visual inspection

Bearings and shaft entry points Visual inspection

Panels, covers, doors Visual inspection

Control devices Visual inspection

Splash area

Non food area

Services

Note 1. Closed food processing machinery is considered to be cleanable if this can bechecked by means of a practical test of the entire plant or its individual components

Note 2. Open food processing machinery is considered to be cleanable if it complieswith the requirements of this table and of specific standards.

6.0 INSTRUCTIONS FOR USE

Equipment suppliers/manufacturers must provide clear, detailed instructions regarding disassembly (where necessary) and effective cleaning methods. The instructions should also specify the preferred cleaning media and where appropriate, a list of chemicals that should be avoided.

7.0 EQUIPMENT GUIDELINES

7.1 CONVEYORS, ELEVATORS AND HANDLING

7.1.1 Belt Conveyors

7.1.1.1 Hazards

• Difficult to clean and dry under belt • Contamination can build up between side guides and the belt • Edges of belt material can shred and contaminate the product • Contamination can build up on the underside of belt conveyors,

especially solid belt conveyors and on conveyor beds • Belts made from non-food quality plastics can contaminate the product • The securing edges of rubber flaps can fill with debris and are hard to

clean

7.1.1.2 Design Considerations

• The full width of both sides of the conveyor belt should be accessible for cleaning.

• If side guides are fitted over the belt they should be designed so they can be easily removed for cleaning

• Raised edged belts are preferable to flat belts with side guides • The belt tensioning mechanism should be designed so that there are

no ledges or areas that cannot be accessed for cleaning and inspection • Dead plates, transfer plates and ploughs should be designed so that

they can be easily removed for cleaning. • Belts should be easy to slacken so they can be raised clear of the bed

for cleaning of the bed and the reverse side of the belt • Drives should not be mounted over the belt. If it is unavoidable, the drive

should be mounted on a drip tray with drainpipe and there should be sufficient clearance between the mounting frame and the conveyor for cleaning

• At places vulnerable to debris build up, such as at conveyor discharge, removable catch bins or trays should be used, which prevent lost product re-entering the flow of good product

• Belt scrapers, reflection plates and guide rails should be designed so that they are easily removable for cleaning

• Rubber flaps to direct the flow of product should not be used • In situations where contamination can fall into the product from above

e.g. if steps or walkways pass over the conveyor, overhead covers should be provided, that can be easily removed for cleaning

7.1.1.3 Methods of Construction

• Belt conveyor edges should be hygienically sealed to prevent shredding • Covering panels or guards should be constructed without ledges on the

inside. They should be easily accessible for cleaning. • Avoid structural member and other surfaces over the conveyor

where debris or soil could fall onto/into the product. • Idle rollers which contact the belt surface, for example under the

belt return should be easily removable for cleaning • Conveyor rollers should be flat ended and the bearings sealed

7.1.1.4 Materials of Construction

• All contact parts should be made from food quality materials (e.g. plastics and articles in contact with food, 90/128/EEC and modifications) that are suitable for cleaning with alkali solutions

• All structures mounted above the conveyor or that come into direct contact with the product should be made from food quality materials and be suitable for cleaning with alkali solutions

• Splash area: See 5.2.2 in EN 1672-2:2009 • Non-food area: See 5.2.3 in EN 1672-2:2009

7.1.1.5 Surface Finish

• Belt material must be completely impermeable and non-porous to facilitate cleaning

7.1.1.6 References and Further Reading

prEN619 Continuous handling equipment and systems. Safety requirements for mechanical handling of unit loads.

7.1.2 Bucket Conveyors

7.1.2.1 Hazards

• Bucket elevators are very difficult to clean and are not recommended for use in high- risk products

• Difficult to clean buckets • Large sprockets difficult to clean, especially if design of chain guards

does not allow access • Motor drive units are often not cleanable in place • Materials of construction e.g. chains, bearings may not be

compatible with alkali cleaning solutions • The securing edges of rubber flaps can fill with debris and are hard to

clean


• The design should prevent retention of the product • The design should allow all parts of the bucket conveyor to be

cleaned and inspected for cleanliness without the need for dismantling

• The chain tensioning mechanism should be designed so that there are no areas that cannot be accessed for cleaning and inspection.

• Dead plates, transfer plates and ploughs should be designed so that they can be easily removed for cleaning.

• Drives should be designed so that they can be cleaned without the need for dismantling

• Drives should not be mounted over the path of the buckets. If it is unavoidable, the drive shall be mounted on a drip tray with drainpipe and there should be sufficient clearance between the mounting frame and the conveyor for cleaning

• At places vulnerable to debris build up, such as at the discharge, removable catch bins or trays should be used, which prevent lost product re-entering the flow of good product

• Rubber flaps to direct the flow of product should not be used

• In situations where contamination can fall into the product from above e.g. if steps or walkways pass over the conveyor, overhead covers should be provided, that can be easily removed for cleaning

7.1.2.4 Method of Construction

• Covering panels or guards should be constructed without ledges on the inside. They should be easily removable for cleaning.

• Avoid structural member and other surfaces over the conveyor where debris or soil could fall onto or into the product




• Splash area: See 5.2.2 in EN 1672-2:2009• Non-food area: See 5.2.3 in EN 1672-2:2009 • Chains and sprockets should be made from materials which

are compatible with alkali cleaning solutions • All structures mounted above the path of the buckets or that come

into direct contact with the product should be made from food quality materials and be suitable for cleaning with alkali solutions


• Bucket material must be completely impermeable and non-porous to facilitate cleaning


prEN619 Continuous handling equipment and systems. Safetyrequirements for mechanical handling of unit loads.

7.1.3 Vacuum Conveyors

7.1.3.1 Hazards

• Air supply may introduce contamination • Lubricating oil can contaminate the product • Dust contamination at tipping points • Retention of product leading to build up of contamination


• Air filters should be provided to ensure that airborne contaminants do not combine with the product

• Vacuum pumps and other items of equipment should be selected that minimise the risk of lubricant oils contaminating the product

• At places vulnerable to debris build up, such as at the conveyor discharge, removable catch bins or trays should be provided, which prevent lost product re-entering the flow of good product.

• Dust collection equipment should be provided at tipping points to prevent the risk of dust contamination

• Rubber flaps to direct the flow of product should not be used • Smooth surfaces without ledges particularly around gaskets should

be used to prevent the retention and hold-up of product and to facilitate cleaning





• Splash area: See 5.2.2 in EN 1672-2:2009 • Non-food area: See 5.2.3 in EN 1672-2:2009 • Where lubricants are used these should be food quality


• Food contact area material must be completely impermeable and non-porous to facilitate cleaning



7.14 Screw Conveyors

7.1.4.1 Hazards

• Gaps in welding of screws provide sites for contamination • Product can get forced into beams • Horizontal and inclined screws will retain liquids if suitably positioned

drain holes are not provided • If drives are mounted over the product, there is a risk of

cross contamination from gearbox oil • Lubricants can pass through shaft seals into the product • Difficult to inspect for cleanliness • Damage to product


• Drives should not be mounted over the conveyor • At places vulnerable to debris build up, such as at conveyor discharge,

removable catch bins or trays should be used, which prevent lost product re-entering the flow of good product.

• The link between the drive motor and the screw shaft should be designed so that it can be easily cleaned

• Horizontal and inclined conveyors should be fitted with drain valves at the lowest point in the trough so that cleaning fluids and other liquids can be completely removed

• Rubber flaps to direct the flow of product should not be used


• All welds should be continuous • Covering panels or guards should be constructed without ledges on the

inside. They should be easily removable for cleaning. • Structural member and other surfaces over the conveyor where debris

can accumulate and then fall back into the product should be avoided


• All contact parts should be made from food quality materials (e.g. plastics and articles in contact with food, 90/128/EEC and modifications)

that are suitable for cleaning with alkali solutions • All structures mounted above the conveyor or that come into direct

contact with the product should be made from food quality materials and be suitable for cleaning with alkali solutions


• Food quality lubricants should be used in all situations where there is a potential for lubricants to come into contact with the product. Oil levels and oil seals in all such situations should be inspected regularly



• Welds should be ground smooth


prEN619 Continuous handling equipment and systems. Safetyrequirements for mechanical handling of unit loads.

7.1.5 Chain Conveyors

7.1.5.1 Hazards

• Chain links provide many sites for contamination • Bolts and rivets provide sites for contamination and are

generally unsuitable for use in contact with product • Chain can wear and contaminate the product with metal particles • The securing edges of rubber flaps can fill with debris and are hard to

clean


• The chain tensioning mechanism should be designed so that there are no ledges, or areas that cannot be accessed for cleaning and inspection

• Dead plates, transfer plates and ploughs should be designed so that they can be removed for cleaning.

• Drives should not be mounted over the conveyor. If it is unavoidable, the drive should be mounted on a drip tray with drainpipe and there should be sufficient clearance between the mounting frame and the conveyor for cleaning.

• Lubrication systems should not be fitted • At places vulnerable to debris build up, such as at the discharge,

removable catch bins or trays should be used, which prevent lost product re-entering the flow of good product

• Rubber flaps to direct the flow of product should not be used • The use of loose links is preferred to facilitate cleaning


• Nuts and bolts should not be used to join chain links together • Covering panels or guards should be constructed without ledges on the




• All contact parts should be made from food quality materials (e.g. plastic materials and articles in contact with food, 90/128/EEC and modifications) that are suitable for cleaning with alkali solutions







7.1.6 Slat Band/Wire Mesh Conveyors

7.1.6.1 Hazards

• Difficult to clean under slats • Contamination can build up in the slat to slat joint • The securing edges of rubber flaps can fill with debris and are hard to

clean

• Water and soap lubricants can contaminate the product


• The conveyor should be designed so that both sides of the slat band can be cleaned

• CIP systems should be fitted under the slat bands where restricted access makes other methods of cleaning impracticable.

• If side guides are fitted over the slat band they should be designed so they can be easily removed for cleaning

• The chain tensioning mechanism should be designed so that there are no ledges, or areas that cannot be accessed for cleaning and inspection

• Dead plates, transfer plates and ploughs should be designed so that they can be easily removed for cleaning

• Drives should not be mounted over the slat band. If it is unavoidable, the drive should be mounted on a drip tray with drainpipe and there should be sufficient clearance between the mounting frame and the conveyor for cleaning.

• At places vulnerable to debris build up, such as at the discharge, use, removable catch bins or trays should be fitted, which prevent lost product from re-entering the flow of good product

• Rubber flaps to direct the flow of product should not be used • Water and soap lubrication systems should not be fitted • In situations where contamination can fall into the product from above





• Splash area: See 5.2.2 in EN 1672-2:2009 • Non-food area: See 5.2.3 in EN 1672-2:2009 • Covering panels or guards should be constructed without ledges on the




• All product contact parts should be food quality • All structures mounted above the conveyor or that come into direct

contact with the product should be made from food quality materials

and be suitable for cleaning with alkali solutions



• The surface finish required will be determined primarily by the function of the conveyor



7.1.7 Vibratory Conveyors

7.1.7.1 Hazards

• Materials of construction may not be compatible with alkali cleaning solutions

• Gating mechanism at the end of the conveyor e.g. to hopper input, may build up contamination


• Gating mechanisms should be easy to clean and easily removable • If side guides are fitted over the conveyor they should be designed

so they can be easily removed for cleaning • Dead plates, transfer plates and ploughs should be designed so that

they can be easily removed for cleaning. • Drives should not be mounted over the conveyor • At places vulnerable to debris build up, such as at the discharge,

removable catch bins or trays should be fitted, which prevent lost product re-entering the flow of good product.




• Structural member and other surfaces over the conveyor where debris can accumulate and then fall into the product should be avoided





• Splash area: See 5.2.2 in EN 1672-2:2009 • Non-food area: See 5.2.3 in EN 1672-2:2009 • All structures mounted above the conveyor or that come into direct

contact with the product should be made from food quality materials and be suitable for cleaning with alkali solutions



• The surface finish required will be determined primarily by the function of the conveyor, but to promote product flow and avoid product retention and facilitating easy cleaning

7.17.5 References and Further Reading


7.1.8.1 Hazards

• Damage to product • Particles of product can get trapped in the joints of the belt • Contamination may not be seen if it is not possible to inspect the whole of the

conveyor while cleaning • Poor ease of cleaning


• The full width of both sides of the conveyor should be accessible for cleaning and inspection

• If side guides are fitted over the conveyor they should be designed so they can be easily removed for cleaning

• Dead plates, transfer plates and ploughs should be designed so that they can be easily removed for cleaning.

• Drives should not be mounted over the conveyor • At places vulnerable to debris build up, such as at the discharge,

removable catch bins or trays should be fitted, which prevent lost product re-entering the flow of good product





• Structural member and other surfaces over the conveyor where debris can accumulate and then fall into the product should be avoided




• Splash area: See 5.2.2 in EN 1672-2:2009. • Non-food area: See 5.2.3 in EN 1672-2:2009.


• Suitable for CIP and minimise product residue left on the belt



7.2 MULTIHEAD WEIGHERS

7.2.1 Description of Equipment and Definition

Figure 1: Multihead Weigher Schematic

1

8 2/3

4

5

96

7

Typical Multihead weigher

Table 2: Description of Figure 1

Item Description Area type

1 Inlet chute Chute used to guide food onto the weigher Food area

2 Centre Cone Central feeder used to spread food evenly on to a Food areanumber of radial feeders

3 Radial feeder Feeder used to deliver food to an individual Food areaweigh-head

4 Pre-Feed hopper Hopper used to pool food fed from a radial feeder Food areaand deliver it to the weigh hopper on demand

5 Weigh hopper Hopper used to weigh food Food area

6 Discharge chute Chute used to guide the discharged food into the Inside: Food areapackaging equipment Outside: Splash area

7 Timing hopper Hopper used to catch discharged food and release Food areait into the packaging equipment.

8 Central Cage Central support for the hoppers, housing Food areaelectronics and hopper drives

9 Main Frame The base usually housing electrical power circuits. Splash area

- Monitor Control unit for programming and operating the Non-food areaequipment (not shown here)

7.2.2 Hazards

• Contamination of product from foreign bodies entering the process • Stagnation of product during the weighing process • Contamination of product from residual cleaning materials • Infestation or putrefaction in areas concealed from cleaning

Poor design or inappropriate installation of the multihead may result in exposure to any or all of these hazards.

7.2.3 Design Considerations

• Due to the open nature of this equipment, overhead equipment should be sited carefully to minimise the risk of foreign bodies falling onto/into the product.

• The system design should incorporate metal detection equipment, appropriately positioned to check the product after the last point of potential contamination, e.g. in the forming tube of a bagmaker or further downstream to check the closed package. Wherever it is sited there should be a rejection device, which shall separate contaminated product from production and not allow re-contamination.

• The method of mounting the equipment should be carefully considered such that it does not impede the ability to clean the surrounding floor area, while at the same time allowing ease of access to remote contact parts for non-CIP cleaning.

• Generally, Multihead weighers' applications do not tend to be suited to CIP methods due to the risk of damaging the under-mounted packaging equipment. Hoppers are to be removed for cleaning and facilities must be provided for the easy transport, handling and disassembly of the weigh head. However, where a CIP regime is required, the design of the Multihead should be such that:-

a) Product can be drained away easily prior to cleaning and b) The hoppers can be held open to allow throughput of cleaning agent

without dead spots c) All contact parts should be easily removed/replaced and, where

possible, similar parts should be interchangeable to simplify cleaning procedures.

d) Contact parts should be designed with simple operation and large radiuses to ensure efficient cleaning methods.

• Multihead select the best combination of hoppers to discharge. It is therefore possible that product remains in one location much longer than desired. To avoid the risk of deterioration, there should be a facility to either

a) Force inclusion of this product within a set time (depending on product) or

b) Reject unused product within a set period of time

• The use of fasteners should be avoided. Where they are found to be necessary they shall be made captive to reduce the risk of falling into product.

• The Multihead installation may include a device for feeding product in; it may also include a device for distributing the weighed product to the associated packaging equipment. This shall be manufactured using suitable materials to a design that can be either cleaned in place or removed/dismantled to enable effective cleaning.

• The position and mounting of associated equipment shall not impede the cleaning of, or disassembly for cleaning of the Multihead components.

7.2.4 Method of Construction

• Where irregular surfaces are joined, e.g. the welding brackets to embossed stainless steel, the edges should be sealed to prevent ingress of food or other contaminant into the joint and to facilitate effective cleaning.

7.2.4.1 Inlet Chute

• The inlet chute should be crevice free and should be designed to allow free movement of food without dead spots. The support bracket should not include dead spots where food can become trapped and then be allowed to re-enter production.

7.2.4.2 Centre Cone

• The centre cone should be crevice free and be designed to allow free movement of food without dead spots.

7.2.4.3 Radial Feeders

• Radial feeders should be crevice free and should be designed to allow free movement of food without dead spots where food can become trapped and then be allowed to re-enter production.

• Free movement of food without dead spots will also promote the avoidance of over or underweight packs.

7.3.4.4 Hoppers

• Hoppers should be crevice free and be designed to allow free movement of food without dead spots. The opening mechanics should be designed to be simple for ease and effectiveness of cleaning.

• Where springs are used there should be a method of holding the spring open while cleaning to ensure all soil is removed.

7.2.4.5 Discharge Chute

• The discharge chute (or combination of chutes) should be crevice free and should be designed to allow free movement of food without dead spots.

7.2.5 Materials of Construction

Materials shall be suitable for use in contact with food and able to resist chemical

attack from production or alkali cleaning media

• Where possible, all food areas shall be made from Stainless Steel (SUS 304/316 or equivalent).

• For Multihead in high risk production areas the recommendation for stainless steel is extended beyond contact parts.

• Plastics and other non-stainless materials used for contact surfaces shall be approved to meet the appropriate European, FDA or USDA requirements.

• Plastic and other non-metallic materials should be coloured blue and to increase the likelihood of detection by visual methods should they find their way into the product. They should also be of food-grade materials.

7.2.7 Surface Finish

• Where the use of a liner to improve product flow is necessary, this should only be used as a last resort because it will introduce a crevice in which product can become trapped. Where it is unavoidable, the design of the fastening should be such that it is outside of the normal flow of product and that it facilitates easy removal for thorough cleaning.

• Bonded coating is preferred to loose inserts provided that it is fully bonded leaving no crevices at exposed edges. The coating or insert shall be of a suitable grade of material as described in section 7.2.5.


BS EN ISO 12100-

1: 2003 +A1: 2009 Safety of machinery - Basic concepts, general principles fordesign. Part 1: Basic terminology, methodology

BS EN ISO 12100-1: 2003 +A1: 2009 Safety of machinery - Basic concepts, general principles for

design. Part 2: Technical principles and specifications

EN 1672-2: 2009 Food processing machinery - Basic concepts -Part 2: Hygiene requirements. 1997. CEN publication.

EN 60529: 1991 Specification for degrees of protection provided by enclosures(IP code)

7.3 DEPOSITORS

7.3.1 Description of Equipment

Depositors can be mechanically, pneumatically or servo driven or by a combination of two or more of these methods.

A depositor normally comprises a reservoir for product, a measuring or metering head, a method of delivery from the reservoir to the head and all necessary pipe work and controls associated with these items.

The head can be fixed over or adjacent to the side of a track or belt, along which the target or targets will travel or over a fixed point at which an operator will present individual targets as required. Heads are usually

mounted within a suitably designed and manufactured framework.

7.3.2 Hazards

• Splashing/overspill may be caused by the outlet of the depositor head being positioned too far from the target or being supplied at too great a pressure, through the wrong sized outlet nozzle.

• Dripping may be caused by the liquid still being allowed to escape from the head after delivery has stopped or where the head has an area in the outlet where product can dwell after delivery has stopped and run down under the action of gravity.

• Temperature may be critical for some products. Changes in temperature may result in the liquid changing viscosity with possible significant effects on performance.

• Product damage.

• Pneumatically driven: Air exhaust is a potential contamination source.

• Mechanically driven: Potential contamination from drive system and connections to drive mechanism.

• Temperature critical: Connections to heating/cooling jackets.

• Particulate Depositors: Need to keep particulates in suspension


• Construction shall eliminate all ledges, sharp inaccessible corners and dead areas within the product flow route.

• All food areas must be easily cleanable.

• Product flow adjustment should be within easy reach of the operator, i.e. without necessitating leaning across open food products

• Design to avoid places vulnerable to product build up, but where this is not possible, design to be easily accessible for cleaning

• Any lost product must be prevented from entering the product flow

• Drive units shall be mounted to avoid leakage/lubrication

contaminating open food products.

• Avoid mounting drives over product

• Depositors shall be mobile to enable removal from the line

• Minimise the number of structural members and/or other surfaces where debris or soil could fall onto/into food product flow.

• Design to minimise the need for disassembly and reassembly.

• Any items requiring regular disassembly assembly shall be designed in such a way as to limit the potential for incorrect assembly and use.

• Discharge valves shall be designed to enable safe cleaning, i.e. while disconnected from the energy source.

• All critical operating or safety parts shall be designed so that they can only be fitted correctly or that the system will only operate when they are fitted correctly.

7.3.4 Methods of Construction

• Framework shall be fully welded. Continuous welding is the most cost effective hygienic method of jointing metal components currently available.

• Hollow sections should only be sealed by welding. Plastic end caps etc. are not acceptable as they do not seal against high pressure washing normally used within this industry thus allowing ingress of foreign matter, water etc. inside frame with consequent hygiene problems.

• Where units are fixed to a frame then studs welded to frame or pads with suitable tapped holes should be used a fixing points The frame, if hollow, must never be drilled and tapped as this provides ingress routes for microorganisms and food material.

• All pistons and piston cylinders should be fully demountable to ensure that no area is in contact with food that is concealed from cleaning.

• A minimum practical number of parts should be used.


• All food contact material should be either 316 or other food grade stainless steel, all other materials to be suitable food grade materials.

• All food contact material should be resistant to cleaning agents and elevated temperatures normally associated with cleaning cycles.

• Galvanised, coated or painted surfaces are not acceptable.


• Non-coated surfaces should be used to prevent to flaking into the food flow after prolonged use or damage.

• All welds to be ground smooth to prevent food build up in the food area.

• Food contact surfaces should be polished.

• External surfaces should be polished, discalced and pickled or bead blasted.


BS EN ISO 12100-1: 2003 Safety of Machinery - Basic concepts, general principles for

design. Part 1: Basic terminology, methodology

BS EN ISO 12100-1: 2003 +A1: 2009 Safety of Machinery - Basic concepts, general principles for

design. Part 2: technical principles and specifications

EN 1672-2: 2009 Food Processing Machinery - Basic concepts. Part 2: HygieneRequirements. 1997. CEN publication.

EN 60529: 1991 Specification for Degrees of protection provided by enclosures(IP Code)

ISBN 011 866 335 5 Manual Handling Regulations HSE 1992

ISBN 0 7176 0411 X Manual Handling Regulations HSE 1998

8.0 COMPONENT GUIDELINES

8.1 FRAMEWORKS

8.1.1 Hazards

• Ledges, hollows and crevices trapping debris • Poor access to areas beneath equipment, hindering cleaning


• Framework construction should be as simple as possible with the minimum number of cross members and floor mountings. Strengthening gussets are preferable rather than cross braces. Tubular braces are preferred to angle or rectangular hollow section.

• Hollow section structural members are preferred over angle or channel to minimise ledges and crevices.

• Stiffeners must not form ledges that trap debris. Use hollow section or angle welded all around and capped off both ends.

• Hollow section used as cross bracers should be fitted in a diamond configuration to prevent unnecessary flat surfaces.

• Hollow framework members may be used to accommodate services but entry and exit points must be fully sealed.

• Good access for personnel must be provided for cleaning and maintenance. Reference should be made to BS473-3, BS 470, BS4211 and confined space legislation. Note these standards are being withdrawn in favour of equivalent BS EN standards.

• Fully adjustable feet should be used and the use of fixed feet and shims should be avoided.

• Legs must be kept to a minimum.

• A minimum gap of 200mm should be maintained under all equipment and must be fully and safely accessible for cleaning and inspection. When this gap rule cannot be applied machines can have integral

permanent plinths or skirt which must be effectively sealed to the floor to prevent ingress of materials and wash water under the equipment. Note: Sealing with a silicon surface seal is not sufficient as it is easily washed away.

8.1.3 Method of Construction

• The framework should be fully welded. Continuous welding is the most hygienic method of joining metal components, and so welding should be used wherever possible.

• Hollow sections must be totally sealed, by welding. Plastic end caps are unacceptable. As these do not seal against high pressure washing and allow cleaning fluids to fill the capped sections.

• Hollow sections must not be penetrated by drilled or tapped holes. Weld blind tapped pads or lugs for attachment. All pads must be fully welded to parent metal this includes all nameplates and other attachments.

• The number of fixings requiring floor slab penetration must be

minimised.

• Any floor fixings should be stainless steel and the use of chemical anchors is recommended. All floor fixings should have dome nuts fitted.


• Frameworks in contact with the product shall be fabricated from T316 stainless steel.

• Structural members and guards should be made from T304 stainless steel.

• Galvanised or painted finishes shall not be used in/near food contact areas or where the cleaning regime will damage the finish.


• Food contact surfaces should be polished welds ground flush and polished

• External surfaces should be polished, de-scaled and pickled, or bead blasted.


BS EN 1672 Food processing machinery - Basic concepts. Part 2: Hygiene requirements. 2009.

8.2 HOPPERS AND CHUTES

8.2.1 Hazards

• Entrapment of contents and cleaning solution


• Hopper sides should be vertical or as steep as possible to minimise product lodging.

• All corners to have internal radii of at least 10mm.

• Hoppers that are intended to be CIP cleaned must be designed for CIP, ensuring that the correct type of spray device is selected and all surfaces thoroughly wetted avoiding shadow areas. Correct CIP velocities must be achieved to give adequate cleaning. Provision must be made to enable surface swab samples to be taken.

• Avoid using stiffeners. If stiffeners are required then external bracing is preferred and vertical stiffeners are preferred to horizontal bracing.

• Ensure the rims of panels do not form ledges. Suitably sized drain holes must be added to unavoidable rims on access panels.

8.2.3 Construction Method

• Avoid lapped joints as they trap debris and are impractical to clean and disinfect.

• All internal seams shall be fully welded.

• All butt-welds shall be fully penetrating.

• All welds shall be continuous. Track or stitch welds are not acceptable.


• Hoppers shall be fabricated from 316 or other food grade stainless steel.

• Where possible spun panels should be used, as these give a good radius to corners.


• All internal weld surfaces shall be spatter and crevice free.

• Food contact surfaces should be polished welds, ground flush and polished.

External surfaces should be polished, de-scaled and pickled, or bead blasted.


Hygienic Design of Food Processing Equipment, Technical Manual No. 7 (1983 reprinted 1992), Campden & Chorleywood Food Research Association. Hygienic Design Handbook, Second edition, May 1996, APV, UK

BS EN 1672 Food processing machinery - Basic concepts. Part 2: Hygiene requirements. 2009

8.3 WALKWAYS, HANDRAILS, STEPS AND STAIRS OVER CONVEYORS

8.3.1 Hazards

• Poor resistance to loads and wear • Materials of construction not capable of withstanding cleaning regimes • Absence of free draining • Material dropping onto conveyors/product below


• Avoid crevices, ledges and pockets that could harbour food residue.

• Hollow sections shall be sealed and have no penetrations.

• Careful consideration should be given to the design and use of vertical ladders, which should be built to BS5395.

• Avoid the use of ship type ladders and stairs installed at a rake of 50° through to 65°.


• When designing cross-overs on conveyor systems use solid plate decking and steps to prevent contaminants from falling through. Careful consideration should be given to the fixing of deck plates to structural members to avoid crevices.

• Encase treads of steps and stairs to prevent dirt transferring to the product whenever over or near to product areas. This can be achieved by adding a stainless steel back plate behind stair stringers.

• Decking should have a kick-plate to prevent contaminants from falling over the edge and to keep footwear within the decking. It is preferable to manufacture decking and kick-plate as a one rolled construction. In wet areas effective drainage of solid deck plates must be provided, draining away from product areas.

• Handrails should be continuous, fully welded and circular in sections.

• Stair treads should be adequately spaced from stringers.


• The surface type chosen should balance non-slip and cleanability requirements.

• Open decking must be avoided.


• The surface finish should prevent slips and facilitate cleaning


Hygienic Design Handbook Second edition, May 1996, APV, UK

BS EN ISO 14122-1: 2001 Safety of machinery – Permanent means of access for

machinery – choice of a fixed means of access between two levels

BS EN ISO 14122-2: 2001 Safety of machinery – Permanent means of access for machinery – working platforms and walkways

BS EN ISO 14122-3: 2001 Safety of machinery – Permanent means of access for machinery – stairways, stepladders and guard-rails

8.4 GUARDS, COVERS, PANELS AND CLADDING

Guarding is required primarily for health and safety reasons, but may not be designed with accessibility for cleaning purposes in mind.

8.4.1 Hazards

• Corrosion contaminants • Crevices and sealant resulting in material entrapment • Difficulty in inspecting for cleanliness • Restricted access for cleaning


• Guards, lids, covers and other panels whose removal is necessary for thorough cleaning, should be robust and easy to undo. They should be of manageable sizes and completely detachable. Avoid the use of piano hinges, as they are difficult to clean. Guards must be fully interlocked and integrated into the conveyor safety circuit.

• Components shall be durable and resistant to corrosion, e.g. by alkali cleaning materials

• All removable panels should be designed for easy removal/replacement, be easy to clean, without ledges, crevices and sharp corners. Contour to avoid horizontal surfaces. If sheet edges are folded they must be sealed all around.

• All surfaces must drain away from food areas.

• The strategic use of open mesh windows can assist hosing down.

• The fixing and removal of guards should reflect the frequency of necessary removal, e.g. for cleaning:-

o High frequency tasks, e.g. a shift a day – use interlocked guards o Low frequency tasks, e.g. monthly – use fixed guards

• All guarding must comply with current health and safety legislation and be regularly inspected by a competent person.


• All burrs and sharp edges must be removed in areas accessible to operators.

• Sheet metal panel edges should be finished in one of the following methods:

COMMON STRUCTURE FOOD QUALITY

Unacceptable ledges where Note folded rim is welded

debris can lodge and be and 'capped'. Weld must

difficult to clean be ground and polished


• Materials for splash area: See 5.2.2 in EN 1672-2:2009 • Non food area: See 5.2.3 in EN 1672-2:2009 • Guard design: See BS EN 953: 1988


• Food contact area material must be completely impermeable, non-porous and resistant to corrosive and abrasive cleaning agents

• Guards in the splash area need to be of the same quality as food area guards

• Guards shall be open, laser cut stainless steel to facilitate cleaning and resist cleaning agents


BS EN 953:1998 Safety of machinery. Guards. General requirements for the design and construction of fixed and movable

guards

BS EN 1672 Food processing machinery - Basic concepts. Part 2: Hygiene requirements. 2009

9.0 Hygienic risk assessment

9.1 General

The hazards shall be eliminated or the associated risk reduced by ensuring machinery is properly designed, constructed and capable of being properly installed, operated, cleaned and maintained.

The hygienic requirements of the different areas of the equipment depend upon the functions of the area, the type of food to be processed and the nature of the hazard of the food.

In applying the design and construction criteria the primary objective shall be to eliminate or reduce the risk to an acceptable level (see figure below). The hygienic risk assessment follows the methodology described in EN ISO 14121-1

For further details on Hygienic Risk assessments please refer to BS EN 1672-2.

10.0 Verification of Hygiene requirements

Verification of compliance with hygienic requirements shall be undertaken using one or more of the verification methods give on the table below. For further advice please refer to BS EN 1672-2

Requirement Verification

Hygienic risk assessment Documentary evidence

DurableMaterial specification (food . process and cleaning specifications, etc.) and/or practical or functional test

Cleanable or capable of being disinfected

Visual inspection (of technical drawing or machinery) and/or practical test, micro biological test or function test

Corrosion resistantMaterial specification (food, process and cleaning specifications) and/or practical or functional test

Non toxicMaterial specification or practical test for materials and articles intended to come into contact with food

Non absorbentMaterial specification or practical test for materials and articles intended to come into contact with food

Not transfer undesirable odours, colours or taint to the

food

Material specification or practical test for materials and articles intended to come into contact with food

Not contribute either to the contamination of food or have any adverse influence on the

food

Material specification or practical test for materials and articles intended to come into contact with food

Surface design Visual inspection (of technical drawing or machinery)

Surface finish

Measuring e.g. according to EN ISO 42888

For criteria of acceptability see also machine specific C standards if available

Permanent joints Visual inspection

Dismountable joints Visual inspection

Fasteners Visual inspection

DrainageVisual inspection (of technical drawing and/or machinery) and practical tests

Internal angels and corners Measurements

Dead spaces Visual inspection

Bearings and shaft entry points

Visual inspection

Panels, covers, doors Visual inspection

Control devices Visual inspection

Splash area Compliance with ref subclass 5.3.2 of BS EN1672-2

Non food area Compliance with ref subclass 5.3.3 of BS EN1672-2

Services Compliance with ref subclass 5.3.4 of BS EN1672-2

For further information see BS EN1672-2 section 6

11.0 Annex A

11.1 Informative diagrams

11.2 Supporting Photographs

Gantry deck plates held off frame by supports.

Good practice few parts easy to clean elegant design.

Exposed threads 3 to 5mm Max

Hard to clean dirt trap

Face to face contact

Face to face contact and stitch welding.

Flat plate clean elegant design

Flat plate fully welded, hygienic but high cost

Plate recessed into casting dirt and bug trap.

Small gaps hard to clean

Recess in pulley cannot be cleaned

Face to face contact, tubes inside tubes and open gaps can be a bug and dirt trap.

hygienic design guidelines

Documents

removable

transfer undesirable

chain tensioning

food processing

good hygienic

plastic end

hygienic design

inspection