EHEDG GUIDELINE 欧洲卫生工程设计指引

EHEDG GUIDELINE 欧洲卫生工程 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 指引 EHEDG guideline 欧洲卫生工程设计指引 European Hygienic Engineering & Design Group 欧洲卫生工程设计组织 The EHEDG provides guidance on the hygienic engineering aspects of manufacturing of safe and wholesome food. This is achieved through : Production, publication and updating of guidelines, available in several languages. To bridge the gap between theory and practice, training modules will be created based on the guidelines. Equipment approval through certification to assist equipment suppliers and food manufacturers. Organisation of conferences, regional meetings and training workshops. Regional activities Advisory function to legislators and standards groups (CEN, ISO, etc) EHEDG has EC support through the thematic network, HYFOMA, which is the European network for Hygienic Manufacturing of Food. Its goal is guideline development and dissemination of information. Production, publication and updating of guidelines, available in several languages. The production of guidelines is assured by the subgroups. To bridge the gap between theory and practice, training modules will be created based on the guidelines. Guidelines Doc 1 Microbiologically safe continuous pasteurisation of liquid foods, 1992 Doc 3 Microbiologically safe aseptic packing of food products, 1993 Doc 6 The microbiologically safe continuous flow thermal sterilisation of liquid foods, 1993 Doc 8 Hygienic equipment design criteria, 2004 Doc 9 Welding stainless steel to meet hygienic requirements, 1993 Doc 10 Hygienic design of closed equipment for the processing of liquid food, 1993 Doc 11 Hygienic packing of food products, 1993 Doc 12 The continuous or semi-continuous flow thermal treatment of particulate foods, 1994 Doc 13 Hygienic design of equipment for open processing, 1996 Doc 14 Hygienic design of valves for food processing, 2004 Doc 16 Hygienic pipe couplings, 1997 Doc 17 Hygienic design of pumps, homogenisers and dampening devices, 2004 Doc 18 Passivation of stainless steel, 1998 Doc 20 Hygienic design and safe use of double-seat mixproof valves, 2000 Doc 21 Challenge tests for the evaluation of the hygienic characteristics of packing machines, 2000 Doc 22 General hygienic design criteria for the safe processing of dry particulate materials, 2001 Doc 23 Production and use of food-grade lubricants, 2002 Doc 24 The prevention and control of Legionella spp (incl Legionnaires Disease) in Food Factories, 2002 Doc 25 Design of Mechanical Seals for hygienic and aseptic applications, 2002 Doc 26 Hygienic Engineering of Plants for the Processing of Dry Particulate Materials, 2003 Doc 27 Safe Storage and Distribution of Water in Food Factories, 2004 Doc 28 Water treatment in food factories Doc 29 Packing systems for solid foodstuffs Doc 30 Air Handling in the Food Industry Doc 31 Hygienic Engineering of fluid bed and spray dryer plants Doc 32 Materials of construction for equipment in contact with food Doc 33 Hygienic Engineering of Discharging Systems for Dry Particulate Materials Doc 34 Integration of Hygienic and Aseptic systems, March 2006. Doc 35 Welding of Stainless Steel tubing in the food industry Test methods Doc 2 (Updated) A method for assessing the in-place cleanability of food processing equipment, 2004 Doc 4 A method for the assessment of in-line pasteurisation of food processing equipment, 1993 Doc 5 A method for the assessment of in-line A method for the assessment of in-line steam sterilisability of food processing equipment, 2004 Doc 7 A method for the assessment of bacteria tightness of food processing equipment, 2004 Doc 15 A method for the assessment of in-place cleanability of moderately-sized food processing equipment, 1997 Doc 19 A method for assessing bacterial impermeability of hydrophobic membrane filters, 2000 1、Microbiologically safe continuous pasteurisation of liquid foods, 1992 SG Heat Treatment, 1992) There are many reasons why, in practice pasteurised products sometimes present a microbiological health hazard. Due to distribution in residence time, not all products may reach the temperature required for pasteurisation or may do so for too short a time. Further there may be a risk of contamination with a non-pasteurised product, or the cooling medium. This document describes the requirements for the microbiologically safe continuous pasteurisation of liquid foods without particulates. An update is being prepared. 2、A method for assessing the in-place cleanability of food processing equipment, (SG Test Methods, 2nd edition 2000) To facilitate the design, testing and maintenance of hygienic food processing equipment, it is important to be able to assess the relative cleanability of various components of the equipment using standardised test procedures. This paper describes a standard test procedure for assessing cleanability. It is designed to indicate areas of poor hygienic design of equipment in which product or micro-organisms are protected from the cleaning process. It can also be used to compare the in-place cleanability of different equipment designs. The method is based on comparing (in the laboratory) the cleanability of a test item with that of a straight piece of pipe. The degree of cleanliness is based on the removal of a “soured milk soil” containing bacterial spores and is assessed by evaluating the number of spores remaining after cleaning with a mild detergent. The method is intended as a screening test for hygienic equipment design and is not indicative of the performance of industrial cleaning processes (which depend on the type of soil). (See Doc. 15 for a test procedure designed for moderately-sized equipment.) 3、Microbiologically safe aseptic packing of food products, 1993 SG Packing Machines, 1993) This guideline stresses the need to identify the sources of micro-organisms that may contaminate food in the packaging process, and to determine which contamination rates are acceptably low. It clarifies the difference in risk of infection between aseptic processing and aseptic packing and recommends that aseptic packing machines be equipped with fillers that are easily cleanable, suitable for decontamination and bacteria-tight. Requirements for the machine interior include monitoring of critical decontamination parameters. (See also Doc. 21 on challenge tests). 4、A method for the assessment of in-line pasteurisation of food processing (SG Test Methods,1993) Food processing equipment that cannot be or does not need to be sterilised may need to be pasteurised to inactivate relevant vegetative micro-organisms and fungal spores. It is important to test the hygienic characteristics of such equipment to ensure that it can be pasteurised effectively. This document describes a test procedure to determine whether equipment can be pasteurised by circulation with hot water. 5、A method for the assessment of in-line steam sterilisability of food processing (SG Test Methods,1993) Food processing equipment may need to be sterilised before use, and it is important to ensure that the sterilisation method applied is effective. Thus, it is necessary to determine under which conditions equipment can be sterilised. This paper details the recommended procedure for assessing the suitability of an item of food processing equipment for in-line sterilisation. It is advisable to conduct in-place cleanability trials (ref. Doc.2) prior to this test in order to verify the equipment’s hygienic design. 6、The microbiologically safe continuous flow thermal sterilisation of liquid foods (SG Heat Treatments, 1993) Thermal sterilisation is aimed at eliminating the risk of food poisoning and, when used in conjunction with aseptic filling, at achieving extended product storage life under ambient conditions. Whereas pasteurisation destroys vegetative micro-organisms, sterilisation destroys both vegetative micro-organisms and relevant bacterial spores. Guidelines on continuous pasteurisation of liquid foods have been published earlier (Doc.1). This document presents guidelines on the microbiologically safe continuous sterilisation of liquid products. The technique of Ohmic heating was not considered in this paper but may be included in an update being prepared. 7、A method for the assessment of bacteria tightness of food processing equipment (SG Test Methods, 1993) This document details the test procedure for assessing whether an item of food processing equipment, intended for aseptic operation, is impermeable to microorganisms. Small motile bacteria penetrate far more easily through microscopic passages than (non-motile) moulds and yeasts. The facultative anaerobic bacterium Serratia marcescens (CBS 291.93) is therefore used to test bacteria-tightness or the impermeability of equipment to microorganisms. The method is suitable for equipment that is already known to be in-line steam sterilisable (see also Doc. 5). 8、Hygienic equipment design criteria (SG Design Principles, Second edition 2004) This Guideline describes the criteria for the hygienic design of equipment intended for the processing of foods. Its fundamental objective is the prevention of the microbial contamination of food products. It is intended to appraise qualified engineers who are designing equipment for food processing with the additional demands of hygienic engineering in order to ensure the microbiological safety of the end product. Upgrading an existing design to meet hygiene requirements can be prohibitively expensive and may be unsuccessful and so these are most effectively incorporated into the initial design stage. The long term benefits of doing so are not only product safety but also the potential to increase life expectancy of equipment, reduce maintenance and consequently lower operating costs. This document was first published in 1993 with the intention to describe in more detail the hygienic requirements of the Machinery Directive (98/37/EC ref.1). Parts of it were subsequently incorporated in the standards EN1672-2 and EN ISO 14159. (13 pages) 9、Welding stainless steel to meet hygienic requirements, 1993 (SG Design Principles, 1993) This document describes the techniques required to produce hygienically acceptable welds in thin walled (< 3 mm) stainless steel applications. The main objective is to convey the reasons and requirements for hygienic welding and to provide information on how this may best be achieved. Common weld faults are discussed in relation to the hygienic risks they create and guidelines describe what constitutes a weld of hygienic quality. (The general safety aspects of welding are beyond the scope of this document.) 10、Hygienic design of closed equipment for the processing of liquid food, 1993 (SG Design Principles, 1993) Using the general criteria for the hygienic design of equipment identified in Doc 8, this paper illustrates the application of these criteria in the methods of construction and fabrication of closed process equipment. Examples, with drawings, are given to show how to avoid crevices, shadow zones and areas with stagnating product, and how to connect and position equipment in a process line to ensure unhampered cleaning in-place and draining. Attention is drawn to ways of preventing problems with joints, which might otherwise cause leakage or contamination of product. 11、Hygienic packing of food products, 1993 (SG Packing Machines, 1993) Products with a short shelf-life, or whose shelf life is extended by cold storage or in-pack heat treatments, do not have to conform to such strict microbiological requirements as aseptically packaged foods (Doc 3 discusses aseptic packing.) This paper discusses the packing of food products that do not need aseptic packing but which nevertheless need to be protected against unacceptable microbial contamination. Guidelines are provided for the hygienic design of packing machines, the handling of packing materials and the environment of the packing machines. (See also Doc 21) 12、The continuous or semi-continuous flow thermal treatment of particulate foods (SG Heat Treatment, 1994) Thermal sterilisation is a process aimed at eliminating the risk of food poisoning and, when used in conjunction with aseptic filling, it aims to extend product storage life under ambient conditions. This is achieved by the destruction of vegetative micro-organisms and relevant bacterial spores. Earlier papers presented guidelines on continuous pasteurisation (Doc 1) and sterilisation (Doc 6) of liquid products without particles. This paper presents guidelines on the design of continuous and semi-continuous plants for the heat treatment of particulate foods. Liquid foods containing particulates are inherently more difficult to process than homogenous liquids due to heat transfer limitations in particulate-liquid mixtures and the additional problems of transport and handling. Although this document concentrates on sterilisation processes, the principles are consistent with other heat treatment processes. Ohmic heating techniques are not covered. 13、Hygienic design of equipment for open processing, 1996 SG Design Principles, 1996) For food processing, it is important that the plant design takes into account factors affecting the hygienic operation and cleanability of the plant. (See also previous guidelines on hygienic design criteria Doc 8, hygienic welding Doc 9, and the hygienic design of equipment for closed processing Doc 10.) The risk of contamination of food products with relevant micro-organisms during open processing increases with the opportunity to grow in poorly designed equipment, as well as with the concentration of the micro-organisms in the environment. This means that in open plants, environmental conditions, in addition to appropriate equipment design, have an important influence on hygienic operation. Furthermore, the type of product and the stage of the manufacturing process must be taken into consideration. Open processes incorporate many different types of equipment, including machines for the preparation of dairy products, alcoholic and non-alcoholic drinks, sweet oils, coffee products, cereals, vegetables, fruit, bakery products, meat and fish. This paper deals with the principal hygienic requirements for equipment for open processing. It describes methods of construction and fabrication, giving examples as to how the principal criteria can be met in open process equipment. 14、Hygienic design of valves for food processing, 1996 (SG Valves, 1996) Valves are essential components of all food processing plants, and the quality of the valves used strongly influences the microbiological safety of the food production process. Valves for food contact use must therefore comply with strict hygienic requirements This paper discusses the basic requirements for hygienic and aseptic valves. The guidelines apply to all valves used in contact with food or food constituents that are to be processed hygienically or aseptically. Aside from general requirements with regard to materials, drainability, microbial impermeability and other aspects, additional requirements for specific valve types are also described. (See also Doc. 20 on double-seat mixproof valves.) 15、A method for the assessment of in-place cleanability of moderately-sized A method for the assessment of in-place cleanability of moderately-sized food processing equipment, 1997 (SG Test Methods, 1997) A standard test procedure for assessing the in-place cleanability (i.e. suitability to be cleaned without dismantling) of relatively small equipment (such as pumps, valves and flowmeters) was earlier produced by this subgroup (ref Doc 2). This document describes a test procedure for assessing the in-place cleanability of moderately sized equipment, such as homogenisers. The degree of cleanliness is based on the removal of a fat spread soil, and is assessed by evaluating the amount of soil remaining after cleaning by visual inspection and swabbing of the surface. This method is not as sensitive as the microbiological method described in Doc 2. 16、Hygienic pipe couplings (SG Pipe Couplings, 1997) This document identifies and defines critical design parameters for for pipe couplings which show the following characteristics : easily cleanable in-place; easily sterilisable in place; impervious to micro-organisms, ease to install and reliable. Its scope is limited to welded pipe couplings. Gaskets of various types were tested for reliability and hygienic aspects using EHEDG cleanability test methods and repeated sterilisation. The objective was to provide a reliable dismountable joint which is bacteria-tight at the product side under the conditions of processing, cleaning and sanitation. 17、Hygienic design of pumps, homogenisers and dampening devices SG Pumps, edition 2, 2004) The objective of this guideline is to provide a set of minimum requirements for pumps, homogenisers and dampening devices for hygienic and aseptic applications, to ensure that food products are processed hygienically and safely. Special demand is made on pumps, homogenisers and dampening devices used in the food processing and pharmaceutical industry with regard to CIP-capability, gentle product handling and ease of maintenance. In addition to this, pumps, homogenisers and dampening devices require good mechanical, hydraulic and thermal efficiency, a technically perfect construction and low-cost manufacture. These requirements, their implementation and thereto related design principles are handled in detail in this guideline. The guideline applies to all pumps intended for use in food processing, including centrifugal pumps, piston pumps, lobe rotor pumps, peristaltic pumps, diaphragm pumps, water ring pumps, progressive cavity pumps, screw pumps, gear pumps and also to homogenisers, dampening devices and shall include any valves integral with the pump head and the complete homogeniser head. Differences between the EHEDG Guidelines (Europe) and the 3A standards (USA) are indicated, where appropriate. 18、Passivation of stainless steel, 1998 (EHEDG, 1998) Passivation is an important surface treatment that helps assure the successful corrosion resistant performance of stainless steel used for product contact surfaces (eg tubing/piping, tanks and machined parts used in pumps, valves, homogenisers, de-aerators, process monitoring instruments, blenders, dryers, conveyors, etc). The purpose of this document is to provide manufacturers, users and regulatory personnel with basic information and guidelines relative to equipment passivation. The complete passivation process is described and environmental, as well as safety, concerns are discussed. 19、A method for assessing bacterial impermeability of hydrophobic membrane filters (SG Test Methods, 2000) Research over the last years has shown that the currently used hydrophobic membrane filters, with a pore size of 0.22祄, do not retain micro-organisms under all process conditions. Investigations have been conducted into risk assessment of sterilising hydrophobic membrane filters, evaluating the performance of the filters under a range of operating conditions. To validate the bacterial retention ability of sterilising grade hydrophobic membrane filters, a bacterial aerosol challenge test methodology was developed. 20、Hygienic design and safe use of double-seat mixproof valves SG Valves, 2000) Today, food process plants incorporate various multifunctional flow paths. Often one piping system is cleaned while another still contains product. This simultaneous cleaning can potentially result in the dangerous situation where product and cleaning liquid are separated by just one single valve seat. Any cleaning liquid that leaks across such a seat will contaminate the product. Therefore, often two or three single seat valves in a "block-and-bleed" arrangement are applied. Single-body double-seat butterfly valves are used as well, but these cannot be guaranteed to be mix-proof. This document describes the basic hygienic design and the safe use of single-body double-seat mixproof valves, that ensure that intermixing cannot take place. Surge valves have been used in brewing, beverage, food and milk plants in Europe for 20 years. 21、Challenge tests for the evaluation of the of packing machines (SG Packing Machines, 2000) This is the subgroup’s third guideline. The first two documents (Doc 3 and Doc 11) discuss how packing machines should be designed to comply with hygiene design criteria and thereby with the requirements specified in Annex 1 of the Machinery Directive1. Doc. 21 discusses how to determine whether those criteria are met. This requires validation of the design: measurement of essential parameters and testing to determine whether critical requirements are met. This document gives proven methods for testing the performance of the various functions of packing machines. The test methods may also be useful if the manufacturer wants to optimise or redesign a packing machine and if the food processor wants to compare various packing machines. Upon delivery, a packing machine needs to be checked by a commissioning procedure to be agreed in advance between the food processor and the supplier of the machine. Commissionning may include physical tests as well as microbiological tests. Additional tests are specified for commissioning of machines for aseptic packing, 1 Machinery Directive 98/37/EC – Annex 1, point 2.1, Agri-foodstuffs machinery General hygienic design criteria for the dry particulate materials SG Dry Materials Handling, 2001) In the food industry, many different types of dry materials are produced and handled. Dry food processing and handling requires different types of equipment that are typically associated with wet and liquid products. This is the first in a series of documents covering equipment design, installation and appropriate associated practices. Such practices must take into account the possibility for material lump formation, creation of dust explosion conditions, high moisture deposit, formation in the presence of hot air, and material remaining in the equipment after shutdown. Cleaning procedures are also specific to dry processes, dry cleaning being favoured to reduce risks of contamination. Such procedures are described. Production and use of food-grade lubricants SG Lubricants, 2002) Lubricants, grease and oil are necessary components for the lubrication, heat transfer, power transmission and corrosion protection of machinery, machine parts, instruments and equipment. Incidental contact between lubricants and food cannot always be fully excluded and may result in contamination of the food product. This risk applies equally to ood-grade lubricants and conventional lubricants. (The ISO Committee TC 199 recently f recommended the use of the term "lubricants for incidental food contact" instead of “food-grade lubricants” to eliminate the notion that these lubricants are allowed in food.) This guideline will assist lubricant manufacturers to understand better their responsibilities, based on the principles of GMP, by laying down the general requirements and recommendations for the hygienic manufacture and supply of food-grade lubricants. The document also assists operators by explaining the hazards that may reasonably be expected to occur during the use of food-grade lubricants and the actions required to eliminate these hazards or to reduce their occurrence to acceptable levels. The prevention and control of Legionella spp in Food Factories (SG Process Water, 2002) There are many locations on food industry sites where the potential for the proliferation of Legionella spp in water systems exists. These bacteria can give rise to a potentially fatal disease in humans, which is identified as legionellosis or as legionnaires’ disease. This document applies to the control of Legionella spp. in any undertaking involving a work activity and to premises controlled in connection with a trade, business or other undertaking where water is used or stored and where there is a means of transmitting water droplets which may be inhaled, thereby causing a reasonably foreseeable risk of exposure to Legionella spp. The guidelines summarise the best practice for controlling Legionella in water systems. It consists of two parts; namely, Management Practices and Guidance on the Control of Legionella spp. in Water Systems. The first section describes a management programme, which includes the key elements of : risk identification and assessment; risk management (incl personnel responsibilities); preventing or controlling risk of exposure to the bacteria; and record keeping. The second part provides guidance on the design and construction of cooling systems, and hot and cold water systems as well as the management and monitoring of these systems. Water treatment programmes, with attention to cleaning and disinfection, are also discussed. (SG Process Water, 2002) There are many locations on food industry sites where the potential for the proliferation of Legionella spp in water systems exists. These bacteria can give rise to a potentially fatal disease in humans, which is identified as legionellosis or as legionnaires’ disease. This document applies to the control of Legionella spp. in any undertaking involving a work activity and to premises controlled in connection with a trade, business or other undertaking where water is used or stored and where there is a means of transmitting water droplets which may be inhaled, thereby causing a reasonably foreseeable risk of exposure to Legionella spp. The guidelines summarise the best practice for controlling Legionella in water systems. It consists of two parts; namely, Management Practices and Guidance on the Control of Legionella spp. in Water Systems. The first section describes a management programme, which includes the key elements of : risk identification and assessment; risk management (incl personnel responsibilities); preventing or controlling risk of exposure to the bacteria; and record keeping. The second part provides guidance on the design and construction of cooling systems, and hot and cold water systems as well as the management and monitoring of these systems. Water treatment attention to cleaning and disinfection, are also discussed. programmes, with Design of Mechanical Seals for hygienic and aseptic applications SG Mechanical Seals, 2002) This guideline compares the design aspects of different mechanical seals with respect to ease of cleaning, microbial impermeability, sterilisability or pasteurisability. As such, the document can serve as a guide for suppliers and users of this important component in food processing equipment. Using EHEDG definitions, mechanical seals are classified according to use in the food industry into three categories: Aseptic, Hygienic equipment Class I, and Hygienic Equipment Class II. The guideline covers both single and dual mechanical seals under the first two categories, which by definition, are subject to more stringent hygienic demands. General design criteria are described, as well as the basic requirements for materials used for components in mechanical seals food applications. Materials covered include carbon-graphite, ceramics, elastomers and metals. Hygienic implications of seal elements and components are also discussed. Finally, installation requirements are described and illustrated, taking into account the product environment side, the flushing side and the cartridge design. 26、Hygienic Engineering of Plants for the Processing of Dry Particulate Materials SG Dry Materials Handling, 2003) The hygienic engineering of plants for processing dry particulate materials requires that buildings and each item of equipment be hygienically designed (EHEDG Doc 22). This document describes general engineering guidelines to be applied to ensure that buildings, individual equipment items and accessibility of equipment when integrated within the plant layout are designed so that aspects of the process operation, cleaning and maintenance comply with hygienic design standards. It details requirements related to plant enclosure, including hygienic zoning, building structures and elements (from floor to ceiling) as well as process line installation. Attention is also given to air stream and water related aspects within the plant as well as cleaning and contamination aspects. These general guidelines are applicable to the early stages of overall plant engineering or to an existing plant, which needs upgrading to comply with hygienic design standards. Safe Storage and Distribution of Water in Food Factories SG Process Water, 2004) Water is a vital medium used for many different purposes in the food industry. Systems for storing and distributing water can involve hazards , which could cause water quality to fall below acceptable standards. It is therefore critical to ensure that water storage and distribution in a food manufacturing operation takes place in a controlled, safe way. This Guideline summarizes the best practice for three water categories used in the food industry: product water, domestic water and utility water. Reference is made to Doc. 24 "The prevention and control of Legionella spp (incl Legionnaires' Disease) in Food Factories", 2002 also produced by the subgroup Process Water. Safe and hygienic water treatment in food factories. The choice of the most suitable water treatment depends on the water source and intended applications. Referencing CODEX, WHO and EU Directive 98/83/EC, the Process Water subgroup discusses in this document various techniques in relation to main hazards, 3 sources of which are namely: mechanical design and building; normal operation (including stops); and external factors. Ion exchange, membrane filtration, chlorination/ozonation, and ultra-violet radiation are among the treatments discussed. Other titles from this subgroup are: The prevention and control of Legionella spp (incl Legionnaires' Disease) in Food Factories (2002) and "Safe Storage and Distribution of Water in Food Factories (2004). Hygienic design of packing systems for solid foodstuffs This document addresses packing systems of solid food products and supplements an earlier guideline on "Hygienic packaging of food products", produced by the same subgroup (packing machines). Solid food is characterised as having a water activity of >0.97, low acid, not pasteurised or sterilised after packaging, and distributed through the cool chain. Examples include fresh meat and some meat products, cheeses, ready meals, cut vegetables, etc. Hygiene requirements of the packaging operations-- machinery as well as personnel, are described and reference is made to the American Meat Institute's principles of sanitary design. This title is the fourth in the EHEDG series of guidelines on packing machines, which includes: "Aseptic packaging of food products" and "Challenge testing of machines for liquid and semi liquid products". Guidelines on Air Handling in the Food Industry The controlled properties of air, especially temperature and humidity, may be used to prevent or reduce the growth rate of some micro-organisms in manufacturing and storage areas. The particle content - dust and micro-organisms - can also be controlled to limit the risk of product contamination and hence contribute to safe food manufacture. Airborne contaminants are commonly removed by filtration. The extent and rate of their removal can be adjusted according to acceptable risks of product contamination and also in response to any need for dust control. These guidelines are intended to assist food producers in the design, selection, installation, and operation of air handling systems. Information is provided on the role of air systems in maintaining and achieving microbiological standards in food products. The guidelines cover the choice of systems, filtration types, system concepts, construction, maintenance, sanitation, testing, commissioning, validation and system monitoring. They are not intended to be a specification for construction of any item of equipment installed as part of an air handling system. Each installation needs to take account of local requirements and specialist air quality engineers should be consulted, to assist in the design and operation of the equipment. 31、Hygienic Engineering of fluid bed and spray dryer plants Because these plants handle moist products in an airborne state, they are susceptible to hygiene risks, including a possible transfer of allergens between products. It is therefore critical to apply hygienic design considerations to both the process and machinery to prevent occurrence of such risks. The Dry materials handling subgroup addresses these issues in detail in their latest document. Starting from the basics with regard to the design, construction materials, layout, and zone classification of the drying systems to meet hygienic requirements, the subgroup then outlines component design aspects of the processing chamber, with particular attention to the atomization assembly and the distribution grids for fluidization. Systems for both supply and exhaust air should operate in a hygienic manner and the document lists recommendations for the use and installation of various types of filters. Finally, operational aspects, including sampling, control and general housekeeping are briefly discussed. Materials of construction for equipment in contact with food. August 2005. This Guideline aims to offer a practical 'handbook' for those responsible for the specification, design and manufacture of food processing equipment. Its purpose is to offer guidance on the ways in which materials may behave such that they can be selected and used as effectively as possible. It is hoped that this Guideline will serve as an aide-memoir during the design process, so that equipment manufacturers and end-users can together ensure that all aspects of materials behaviour are taken into account in designing safe, hygienic, reliable and efficient equipment which can be operated, maintained and managed economically. Hygienic Engineering of Discharging Systems for Dry Particulate Materials Discharging systems for dry particulate materials (powders) are of importance since they aim at the transfer, in this case of dry solids, from one system into another without powder spillage, contamination or environmental pollution, and therefore relate to food processing safety. Dust control is an important issue around these discharging systems in relation to environmental hygiene and worker exposure. The introduction of the product into the processing system is therefore a key step in maintaining the sanitation and integrity of the entire process. Many dry systems do not have any additional heating protective steps, as they are merely specialty blending processes. Therefore, any contamination that enters the system will appear to the finished product. This document describes the hygienic design criteria for dry particulate materials discharging systems. Guidelines for the design of bag, big bag, container and truck discharging systems are presented. These guidelines are intended for use by persons involved in the design, sizing, and installation of bag, big bag and truck discharging systems operating under hygienic conditions. Integration of Hygienic and Aseptic systems Hygienic and/or aseptic systems comprise inter alia individual components, machinery, measurement systems, management systems and automation that are used to produce for example food products, medicines, cosmetics, home & personal products and even water products. This horizontal guideline is about the hygienically safe integration of hygienic (including aseptic) systems, focusing on food production. Systems and components are frequently put together in a way that creates new hazards, especially microbiological ones. Deficiencies during the sequence of design, contract, design-change, fabrication, installation and commissioning are often the cause of these failures, even when specific design guidelines are available and are thought to be well understood. Errors in sequencing and content can also result in major penalties in terms of delays and in costs of components and construction. iely effectivelyuu fficient plants and processes This document examines integration aspects that can affect hygienic design, installation, operation, automation, cleaning and maintenance and uses system flow charts and cases describing the integration processes and decision steps. It does not provide detailed guidance on specific manufacturing processes, products, buildings or equipment. Welding of Stainless Steel tubing in the food industry Abundantly illustrated, this paper provides guidelines for the correct execution of on-axis hygienic (sanitary) welding between pipe segments, or between a tube and a control component (e.g. valve, flow meter, instrument tee, etc.) It deals with tube and pipe systems with less than 3.5 mm wall thickness, built in AISI 304(L) (1.4301, 1.4306 or 1.4307), 316(L) (1.4401, 1.4404 or 1.4435), 316Ti (1.4571) or 904L (1.4539) and their equivalents. The requirements for a weld destined for hygienic uses are first described, then the possible defects which can affect the weld are listed, and at the end the procedure for a state-of-the-art welding execution is illustrated, including preparation of pipe ends, final inspection and a trouble shooting guide. It mainly refers to the part of the weld in contact with the finished or intermediate product and the only welding method considered is the GTAW (Gas Tungsten Arc Welding, commonly known as TIG) without filler material (autogenous weld), since this technique is capable of assuring the best performance in the execution of welds for the fabrication of thin wall stainless steel tubing. Inspection of welds will be covered in more detail in the next project.