The hygienic design of chilled foods plant 365 through into high risk via a pipe in the dividing wall. The kettles need to be positioned in low risk at a height such that the transfer into high risk is wel above ground level. Installations have been encountered where receiving vessels have had to be placed onto the floor to accept product transfer 13.3.2 Product decontamination Fresh produce to be processed in high care should enter high care via a decontamination operation, usually involving a washing process with the washwater incorporating a biocide. The use of chlorinated dips, mechanically stirred washing baths or jaquzzi' washers are the most common method, though alternative biocides are also used(e.g. bromine, chlorine dioxide, ozone, organic acids, peracetic acid, hydrogen peroxide) In addition, it is now seen as increasingly important, following a suitable risk assessment, to decontaminate the outer packaging of various ingredients on entry into high risk(e.g. product cooked elsewhere and transported to be processed in the high-risk area, canned foods and some overwrapped processed ingredients). Where the outer packaging is likely to be contaminated with food materials, decontamination is best done using a washing process incorporating a disinfectant (usually a quaternary ammonium compound). If the packaging is clean, the use of UV light has the advantage that it is dry and thus limits potential environmental microbial growth Decontamination systems have to be designed and installed such that they satisfy three major criteria 1. As with heat barriers, decontamination systems need to be installed within the low/high-risk barrier to minimise the free space around them. As a very minimum, the gap around the decontamination system should be smaller than the product to be decontaminated. This ensures that all ingredients in high risk must have passed through the decontamination system and thus must have been decontaminated (it is impossible to visually assess whether the outer surface of an ingredient has been disinfected, in contrast to whether an ingredient has been heat processed) 2. Prior to installation, the decontamination process should be established and verified. For a wet process, this will involve the determination of a suitable disinfectant that combines detergency and disinfectant properties and a suitable application temperature, concentration and contact time. Similarly, for UV light, a suitable wavelength, intensity and contact time should be determined. The same degree of decontamination should apply to all the product surfaces or, if this is not possible, the process should be established for the surface receiving the least 3. After installation, process controls should be established and may include calibrated, automatic disinfectant dosing, fix speed conveyors, UV light intensity meters etc. In process monitoring may include the periodic checking for critical parameters, for example blocked spray nozzles or UV
through into high risk via a pipe in the dividing wall. The kettles need to be positioned in low risk at a height such that the transfer into high risk is well above ground level. Installations have been encountered where receiving vessels have had to be placed onto the floor to accept product transfer. 13.3.2 Product decontamination Fresh produce to be processed in high care should enter high care via a decontamination operation, usually involving a washing process with the washwater incorporating a biocide. The use of chlorinated dips, mechanically stirred washing baths or ‘jaquzzi’ washers are the most common method, though alternative biocides are also used (e.g. bromine, chlorine dioxide, ozone, organic acids, peracetic acid, hydrogen peroxide). In addition, it is now seen as increasingly important, following a suitable risk assessment, to decontaminate the outer packaging of various ingredients on entry into high risk (e.g. product cooked elsewhere and transported to be processed in the high-risk area, canned foods and some overwrapped processed ingredients). Where the outer packaging is likely to be contaminated with food materials, decontamination is best done using a washing process incorporating a disinfectant (usually a quaternary ammonium compound). If the packaging is clean, the use of UV light has the advantage that it is dry and thus limits potential environmental microbial growth. Decontamination systems have to be designed and installed such that they satisfy three major criteria. 1. As with heat barriers, decontamination systems need to be installed within the low/high-risk barrier to minimise the free space around them. As a very minimum, the gap around the decontamination system should be smaller than the product to be decontaminated. This ensures that all ingredients in high risk must have passed through the decontamination system and thus must have been decontaminated (it is impossible to visually assess whether the outer surface of an ingredient has been disinfected, in contrast to whether an ingredient has been heat processed). 2. Prior to installation, the decontamination process should be established and verified. For a wet process, this will involve the determination of a suitable disinfectant that combines detergency and disinfectant properties and a suitable application temperature, concentration and contact time. Similarly, for UV light, a suitable wavelength, intensity and contact time should be determined. The same degree of decontamination should apply to all the product surfaces or, if this is not possible, the process should be established for the surface receiving the least treatment. 3. After installation, process controls should be established and may include calibrated, automatic disinfectant dosing, fix speed conveyors, UV light intensity meters etc. In process monitoring may include the periodic checking for critical parameters, for example blocked spray nozzles or UV The hygienic design of chilled foods plant 365
366 Chilled foods ntensity and, from the low-risk side, the loading of the transfer or to ensure that product is physically separated such that all product are exposed 13.3.3 Other product transfer It is now poor practice to bring outer packaging materials into high risk. All ingredients and product packaging must, therefore, be de- boxed and transferred nto high risk Some ingredients, such as bulk liquids that have been heat-treated or inherently stable(e.g. oils or pasteurised dairy products), are best handled being pumped across the low/high-risk barrier directly to the point of use. Dry stable bulk ingredients(e.g. sugar)can also be transferred into high risk via sealed conveyors For non-bulk quantities, it is possible to open ingredients at the low/high-risk barrier and decant them through into high risk via a suitable transfer system(e.g a simple funnel set into the wall), into a receiving container. Transfer systems should, preferably, be closeable when not in use and should be designed to be cleaned and disinfected, from the high-risk side, prior to use as appropriate 13.3.4 Packaging Packaging materials(film reels, cartons, containers, trays etc. )are best supplied to site ' double bagged. This involves a cardboard outer followed by two plastic bag layers surrounding the packaging materials. The packaging is brought on site, de-boxed, and stored double bagged until use in a suitable packaging store When called for in high risk, the packaging material is brought to the low/high risk barrier, the outer plastic bag removed and the inner bag and packaging enters high risk through a suitable hatch. The second plastic bag keeps the ackaging materials covered until they are loaded onto the line or the packaging he hatch, as with all openings in the low/high-risk barrier, should be as small possible and should be closeable when not in use. This is to reduce airflow through the hatch and thus reduce the airflow requirements for the air handling systems to maintain high-risk positive pressure. For some packaging materials especially heavy film reels, it may be required to use a conveyor system for moving materials through the hatch. An opening door or preferably, double door airlock, should only be used if the use of a hatch is not technically possible and suitable precautions must be taken to decontaminate the airlock after use 13.3.5 Liquid and solid wastes On no account should low-risk liquid or solid wastes be removed factory via high risk and attention is required to the procedures for removing high-risk wastes. The handling of liquid wastes from low and high risk is described later in this chapter in the section on drainage
lamp intensity and, from the low-risk side, the loading of the transfer conveyor to ensure that product is physically separated such that all product surfaces are exposed. 13.3.3 Other product transfer It is now poor practice to bring outer packaging materials into high risk. All ingredients and product packaging must, therefore, be de-boxed and transferred into high risk. Some ingredients, such as bulk liquids that have been heat-treated or are inherently stable (e.g. oils or pasteurised dairy products), are best handled by being pumped across the low/high-risk barrier directly to the point of use. Dry, stable bulk ingredients (e.g. sugar) can also be transferred into high risk via sealed conveyors. For non-bulk quantities, it is possible to open ingredients at the low/high-risk barrier and decant them through into high risk via a suitable transfer system (e.g. a simple funnel set into the wall), into a receiving container. Transfer systems should, preferably, be closeable when not in use and should be designed to be cleaned and disinfected, from the high-risk side, prior to use as appropriate. 13.3.4 Packaging Packaging materials (film reels, cartons, containers, trays etc.) are best supplied to site ‘double bagged’. This involves a cardboard outer followed by two plastic bag layers surrounding the packaging materials. The packaging is brought on site, de-boxed, and stored double bagged until use in a suitable packaging store. When called for in high risk, the packaging material is brought to the low/highrisk barrier, the outer plastic bag removed and the inner bag and packaging enters high risk through a suitable hatch. The second plastic bag keeps the packaging materials covered until they are loaded onto the line or the packaging machine. The hatch, as with all openings in the low/high-risk barrier, should be as small as possible and should be closeable when not in use. This is to reduce airflow through the hatch and thus reduce the airflow requirements for the air handling systems to maintain high-risk positive pressure. For some packaging materials, especially heavy film reels, it may be required to use a conveyor system for moving materials through the hatch. An opening door or preferably, double door airlock, should only be used if the use of a hatch is not technically possible and suitable precautions must be taken to decontaminate the airlock after use. 13.3.5 Liquid and solid wastes On no account should low-risk liquid or solid wastes be removed from the factory via high risk and attention is required to the procedures for removing high-risk wastes. The handling of liquid wastes from low and high risk is described later in this chapter in the section on drainage. 366 Chilled foods
The hygienic design of chilled foods plant 367 Solid was ive fallen on the floor or equipment, etc., through normal ould be bagged-up or placed in easily cleanable bins, on mensurate with good housekeeping practices. It may also be necessary solid waste product from the line at break periods or to facilitate line product changes. Waste bags should leave high risk in such a way that they minimise any potential cross-contamination with processed product In the reverse oquct. For small quantities of bagged waste, existing hatches should be used e.g. the wrapped product exit hatches or the packaging materials entrance hatch, as additional hatches increase the risk of external contamination and put extra demands on the air handling system. For waste collected in bins, it may be necessary to decant the waste through purpose built, easily cleanable from high risk, waste chutes that deposit directly into waste skips. Waste bins should be colour coded to differentiate them from other food containers and should only be used for waste 13.3.6 Surfaces In this context, surfaces are associated with sealed low/high-risk physical junctions and are concerned with floors, walls, doors and false or suspended ceilings. Detailed descriptions on the requirements for these areas are contained in the Construction section later in this chapter 13.3.7 Personnel Within the factory building, provision must be made for adequate and suitable staff facilities and amenities for changing, washing and eating. There should be lockers for storing outdoor clothing in areas that must be separate from those for storing work clothes. Toilets must be provided and must not open directly into food-processing areas, all entrances of which must be provided with handwashing facilities arranged in such a way that their ease of use is maximised. In addition, staff (including visitors and contractors etc. )have personal responsibilities which they should follow to ensure good hygienic practices. These are normally formulated as the factory hygiene policy and typically include the following 1. Protective clothing, footwear and headgear issued by the company must be worm and must be changed regularly. When considered appropriate by management, a fine hairnet must be worn in addition to the protective headgear provided. Hair clips and grips should not be worn. Protective clothing must not be worn off the site and must be kept in good 3. Beards must be kept short and trimmed and a protective cover worn when considered appropriate by management 4. Nail varnish, false nails and make up must not be worn in production areas
Solid wastes that have fallen on the floor or equipment, etc., through normal production spillages, should be bagged-up or placed in easily cleanable bins, on an on-going basis commensurate with good housekeeping practices. It may also be necessary to remove solid waste product from the line at break periods or to facilitate line product changes. Waste bags should leave high risk in such a way that they minimise any potential cross-contamination with processed product and should, preferably, not be routed in the reverse direction to the product. For small quantities of bagged waste, existing hatches should be used e.g. the wrapped product exit hatches or the packaging materials entrance hatch, as additional hatches increase the risk of external contamination and put extra demands on the air handling system. For waste collected in bins, it may be necessary to decant the waste through purpose built, easily cleanable from high risk, waste chutes that deposit directly into waste skips. Waste bins should be colour coded to differentiate them from other food containers and should only be used for waste. 13.3.6 Surfaces In this context, surfaces are associated with sealed low/high-risk physical junctions and are concerned with floors, walls, doors and false or suspended ceilings. Detailed descriptions on the requirements for these areas are contained in the Construction section later in this chapter. 13.3.7 Personnel Within the factory building, provision must be made for adequate and suitable staff facilities and amenities for changing, washing and eating. There should be lockers for storing outdoor clothing in areas that must be separate from those for storing work clothes. Toilets must be provided and must not open directly into food-processing areas, all entrances of which must be provided with handwashing facilities arranged in such a way that their ease of use is maximised. In addition, staff (including visitors and contractors etc.) have personal responsibilities which they should follow to ensure good hygienic practices. These are normally formulated as the factory hygiene policy and typically include the following: 1. Protective clothing, footwear and headgear issued by the company must be worn and must be changed regularly. When considered appropriate by management, a fine hairnet must be worn in addition to the protective headgear provided. Hair clips and grips should not be worn. 2. Protective clothing must not be worn off the site and must be kept in good condition. 3. Beards must be kept short and trimmed and a protective cover worn when considered appropriate by management. 4. Nail varnish, false nails and make up must not be worn in production areas. The hygienic design of chilled foods plant 367
368 Chilled foods 5. False eyelashes, wrist watches and jewellery (except wedding rings, or the national equivalent, and sleeper earrings)must not be worn 6. Hands must be washed regularly and kept clean at all times 7. Personal items must not be taken into production areas unless carried in inside overall pockets(handbags, shopping bags, etc. must be left in the lockers provided) 8. Food and drink must not be taken into or consumed in areas other than the rest areas and the staff canteen/restaurant 9. Sweets and chewing gum must not be consumed in production areas 10. Smoking or taking snuff is forbidden in food production, warehouse and distribution areas where 'No Smoking notices are displayed 11. Spitting is forbidden in all areas on the site 12. Superficial injuries(e.g. cuts, grazes, boils, sores and skin infections)must be reported to the medical department or the first aider on duty via the line supervisor and clearance obtained before the operative can enter production areas 13. Dressings must be waterproof, suitably coloured to differentiate them from product and contain a metal strip as approved by the medical department 14. Infectious diseases(including stomach disorders, diarrhoea, skin conditions nd discharge from eyes, nose or ears) must be reported to the medical department or first aider on duty via the line supervisor. This also applies to staff returning from foreign travel where there has been a risk of infection 15. All staff must report to the medical department when returning from both certified and uncertified sickness With regard to high-risk operatives, however, personnel facilities and requirements must be provided in a way that minimises any potential con- tamination of high-risk operations. The primary sources of potential contamina- tion arise from the operatives themselves and from low-risk operations. This necessitates further attention to protective clothing and, in particular, special arrangements and facilities for changing into high-risk clothing and entering high risk. Best practice with respect to personnel hygiene is continually developing and has been recently reviewed by Guzewich and Ross(1999), Taylor and Holah(2000)and Taylor et al.(2000) High-risk factory clothing does not necessarily vary from that used in low risk in terms of style or quality, though it may have received higher standards of laundry, especially related to a higher temperature process, sufficient to significantly reduce microbiological levels. Indeed some laundries now operate to the same low/high-risk principles as the food industry such that dirty laundry enters'low risk, is loaded into a washing machine that bridges a physical divide is cleaned and disinfected and exits into high risk to be dried and packed Additional clothing may be worn in high risk, however, to further protect the food being processed from contamination arising from the operatives body (e.g gloves, sleeves, masks, whole head coveralls, coats with hoods, boiler suits etc. ) All clothing and footwear used in the high-risk area is colour
5. False eyelashes, wrist watches and jewellery (except wedding rings, or the national equivalent, and sleeper earrings) must not be worn. 6. Hands must be washed regularly and kept clean at all times. 7. Personal items must not be taken into production areas unless carried in inside overall pockets (handbags, shopping bags, etc. must be left in the lockers provided). 8. Food and drink must not be taken into or consumed in areas other than the rest areas and the staff canteen/restaurant. 9. Sweets and chewing gum must not be consumed in production areas. 10. Smoking or taking snuff is forbidden in food production, warehouse and distribution areas where ‘No Smoking’ notices are displayed. 11. Spitting is forbidden in all areas on the site. 12. Superficial injuries (e.g. cuts, grazes, boils, sores and skin infections) must be reported to the medical department or the first aider on duty via the line supervisor and clearance obtained before the operative can enter production areas. 13. Dressings must be waterproof, suitably coloured to differentiate them from product and contain a metal strip as approved by the medical department. 14. Infectious diseases (including stomach disorders, diarrhoea, skin conditions and discharge from eyes, nose or ears) must be reported to the medical department or first aider on duty via the line supervisor. This also applies to staff returning from foreign travel where there has been a risk of infection. 15. All staff must report to the medical department when returning from both certified and uncertified sickness. With regard to high-risk operatives, however, personnel facilities and requirements must be provided in a way that minimises any potential contamination of high-risk operations. The primary sources of potential contamination arise from the operatives themselves and from low-risk operations. This necessitates further attention to protective clothing and, in particular, special arrangements and facilities for changing into high-risk clothing and entering high risk. Best practice with respect to personnel hygiene is continually developing and has been recently reviewed by Guzewich and Ross (1999), Taylor and Holah (2000) and Taylor et al. (2000). High-risk factory clothing does not necessarily vary from that used in low risk in terms of style or quality, though it may have received higher standards of laundry, especially related to a higher temperature process, sufficient to significantly reduce microbiological levels. Indeed some laundries now operate to the same low/high-risk principles as the food industry such that dirty laundry enters ‘low risk’, is loaded into a washing machine that bridges a physical divide, is cleaned and disinfected and exits into ‘high risk’ to be dried and packed. Additional clothing may be worn in high risk, however, to further protect the food being processed from contamination arising from the operatives body (e.g. gloves, sleeves, masks, whole head coveralls, coats with hoods, boiler suits, etc.). All clothing and footwear used in the high-risk area is colour coded to 368 Chilled foods