Hygiene Design B PDF

HYGIENE DESIGN PART B:HYGIENE DESIGN  Cleaning and Sanitation Cleaning and sanitisation of process plant is one of the most critical aspects of food processing to ensure the health and safety of the consumer. Cleaning and disinfection of food contact surfaces and the environment is done;...

HYGIENE DESIGN PART B:HYGIENE DESIGN  Cleaning and Sanitation Cleaning and sanitisation of process plant is one of the most critical aspects of food processing to ensure the health and safety of the consumer. Cleaning and disinfection of food contact surfaces and the environment is done; As part of the achievement of overall control (chemical, physical, microbiological) of a specific ingredient or food product handled by a particular item or line of equipment. To maintain the performance of equipment, e.g. a filler, within design limits. Because it is part of good plant management which has an important effect on employee morale.  Cleaning: Dry Cleaning Dry cleaning is essentially defined as the mechanical removal of soils using sweeping, brushing, wiping, blowing and vacuuming. Usually, surfaces are scraped or brushed or cleaned by vacuuming and 70% ethanol (ethyl alcohol) is often used as a sanitizer for surfaces and small parts but must be allowed to dry thoroughly before the equipment is re-used. Dry cleaning is appropriate when dry products or soils such as flours, cereals, dried milk powders, or chocolate are handled. Vacuuming does not spread dust and dirt but picks it up. It also removes deeply imbedded dust and dirt. It is therefore, in principle, the desirable system to use. Disinfection following dry cleaning is not easy, although 70% ethanol may be used and allowed to dry off before equipment is reassembled. Dry cleaning methods are used where the products are hygroscopic or where water can react to form hard deposits which are difficult to remove. Also, equipment for handling dried foods, i.e, elevators for carrying nuts or cereal products, may well not be designed or adaptable for wet cleaning.  Dry Cleaning: Vacuum Systems Vacuum cleaning systems must therefore remove food residues. Vacuum systems: Vacuum system consist of two commonly used industrial system: Central and portable vacuum systems. Central vacuum system: The design of a central vacuum system must satisfy specific needs which must clearly defined. These system can be used for wall, floor, ceiling cleaning. They can also be used to clean equipment and pick up spills. They can be used at inspection tables to remove objectionable materials and for wet pickups. It is critical that each specific job describe the handling characteristics and densities of the material to be picked up by the system. Once it has been determined what the system is do and how it is to do it, then it must be properly sized and located. The number, type, size and location of inlet valves needs to be decided/identified. Number of inlet valves to be used at one time must be identified/decided. If the number of inlets used at one time is greater than that which the system is designed for, the system will be ineffective. Valves used for floor cleaning should be about three to five feet (0.9-1.5 m) from the floor. For inspection tables inlet valves should be adjacent to the point of operation. For high ceilings or roof cleaning, the valve should be located near the use point. Stations must be located so that no more than 50 feet (15.2 m) of the hose is required to clean and entire area from one valve station. In congested areas or where heavy floor deposits or spills are anticipated, or where heavy spot cleaning is required, the inlet valves should be closer so that it is only necessary to use only 25 Foot hoses. Thus, placement of inlet valves is critical with respect to operator convenience and proximity to point of use. If personnel; must travel long distances for hoses adjustments etc., then the system will not be optimally used due to personnel inconvenience. Central vacuum system layout/parts include: Hoses: One and a half inch inside diameter (38.1 mm) rubber hose is satisfactory for most cleaning requirements ensuring effective cleaning. The larger sizes (2inch: 50.8 mm) have corresponding greater capacities and are normally used to pick up large spills, clean large tanks. Dry Cleaning: Vacuum Systems Central vacuum system: Separators: The usual type of central vacuum cleaner applications in the food plant will benefit from primary and secondary separator in order to separate out the collected material form air. The function of a primary unit is to separate the majority of the solid bulk material from the stream, particularly the larger particles and heavier dust. Air proceeds to the secondary unit where final filtering occurs as it passes through clog bags. This two-step separation greatly improves separating efficiency and reduces system resistance, which optimises the overall performance level of the total system. Single stage separation should be used only for extremely light dust. Wet pickup systems require separators specifically designed for wet material separations. Wet separators must be placed where they will not be affected by freezing temperature. Advantages of central vacuum system: It has more power. Several cleaning people can use it at the same time. Can be used to clean-up product spills. Can be used in emergency dust control. Can be Used to safely clean equipment that under other circumstances might have to be shut down for cleaning.  Dry Cleaning: Vacuum system Portable vacuum system: Most manufacturing plants will have areas that are not accessible by central cleaning systems, and areas thar are difficult to get to. The usage of a portable vacuum cleaning system is ideal in such cases. Portable vacuum systems includes portable dry vacuums and portable wet vacuums. These vacuum systems are compact, lightweight and easy to transport. Suitable for cleaning small areas, machines and equipment.  Cleaning: Wet Cleaning Wet cleaning: It is a cleaning method that involves the use of water, appropriate chemicals and employing series of water rinses including pre and post detergent rinses. Wet cleaning may be done out of place or in place or, on large equipment, by a mixture of both methods as appropriate. Cleaning-out-of-place (COP) and Cleaning-in-place (CIP) system/methods are the most commonly used wet cleaning system. Cleaning-out-of-place (COP) COP system/methos: Essentially refers to the moving of equipment from its normal location (and /or disassembling it and removing it form its normal location) for cleaning. Steps of COP: Dismantle the equipment to expose the surfaces to be cleaned. Small parts and components may be removed for cleaning in a wash area equipped with sinks, hoses, storage racks, ultrasonic baths, recirculating tank washers, etc. Clear product using shovels, scrapers, brushes, squeegees, hot or cold, low- or high pressure hoses, or flushing with water, as appropriate. Apply detergent used, as mechanical aids to soil removal, brushes, ‘boiling’, high- or low-pressure hoses as appropriate. Thoroughly rinse all food-handling parts of the equipment with cold potable water of suitable quality. Sanitizing is best done after cleaning and, if chemicals are used, should normally be followed by a final rinse to remove the sanitizing agent. A final rinse is not always necessary, i.e. if Quaternary ammonium compounds have been used at the permitted, appropriate level. After the final rinse, complete the reassembly of equipment and allow to drain and dry. Cleaning: Wet Cleaning Cleaning-in-place (CIP) CIP systems can be used to clean pipping systems, tanks, larger pieced of equipment in place (without disassembly) where interior product zones are fully exposed, and soil can be readily washed away by the flow of the cleaning solution. The system use high volumes of water to wash away soil. The success of the system is keyed to proper water flow, velocity and temperature selection of the right cleaning chemicals. CIP system are mainly used for liquid handling process systems. Steps of CIP: Draining the system of product. Prepare the circuit(s), i.e. by switching controls to ‘clean’, installing key pieces or flow plates, confirming availability of detergents, etc. Pre-rinse to remove product residues (gross soil). Circulate hot detergent to remove residual soil. Rinse with potable water of suitable quality. This rinse is the intermediate rinse if chemical sanitizing and or acid scale removal is included in the CIP cleaning. It is the final rinse if there is no further step in the CIP cleaning. Sanitize to reduce microbial numbers to an acceptable level. Final rinse with potable water of suitable quality  Wet Cleaning: Cleaning/Washing rooms The removed equipment (COP) or components are generally taken to the cleaning/was room that has been specially designed and equipped for cleaning out pf place. This room is sometimes used to clean utensils, portable equipment, trays and pans etc. The equipment cleaning room should be constructed of moisture-impervious material that are easy to clean. The room must be large enough to accommodate the largest piece of equipment likely to be cleaned in it. Building materials/Requirements for the cleaning room: Constructed walls, ceilings and floor materials must be easily wet cleaned. Ceramic or glazed tile for the walls and ceiling must be used. Floors must be quarry tile or acid-proof brick. The floor should have a floor drain (complete with grate, screen and trap) and should slope to the drain at the rate of 3/16 inch per foot. In the wash area, usage of single or double doors made of metal, rubber or fibreglass. Doors must be wide enough to allow clearance for the largest piece of equipment to be cleaned. Room must have an exhaust fan to expel steam vapours. Potable Water and Water Hardness Water used in cleaning must be potable, i.e. fit for human consumption. It is therefore often considered ‘pure’. Chemically, this is not correct since water falling as rain absorbs carbon dioxide from the air and becomes a weak solution of carbonic acid. This reacts with calciferous rocks such as chalk and limestone to form bicarbonates and dissolves other materials from the soil and rocks. These dissolved salts produce ‘hardness’ in water. This is apparent domestically by the formation from soap of a ‘curd’ with a hard water. Water hardness may be ‘temporary’ when it can be removed by boiling or ‘permanent’ if it cannot. ‘Temporary’ hardness, which can be removed by boiling, results in a precipitation of a white chalky material usually called ‘fur’ if soft and ‘scale’ if hard. Hard water reduces the cleaning action of most detergents. Hard water can create number of surface scale or surface film problems such as rust formation and calcium deposits. Hardness in water for cleaning can be overcome either by water conditioning systems/processes. Conditioning of water involves the removal of scale forming calcium and magnesium ions which are constituents of hard water. Sodium zeolite softening is the most common conditioning system. Dealkalising system is another form of condition water. Dealkalising reduces the alkalinity of the treated water and the subsequent formation of carbon dioxide.  Food Soils Food soil is generally defined as unwanted matter on food-contact surfaces. Soil is visible or invisible. Soils can be simple or highly complex mixtures depending on the food product that is being processed. The soil main types include Acids soils (Fats, proteins, carbohydrates). Alkaline soils (mineral salts) Condition of soil: Soils can be solid, semi-solid, liquid or mixture. Constraints in the removal of soil: These include such factors as: Design, construction, fabrication or installation of equipment or environment. A simple example is that strong alkalis should not be used on aluminum surfaces. Water hardness. Availability of detergent materials or cleaning aids, i.e. Clean-in-Place (CIP) circuits or High Pressure Low Volume (HPLV) hoses.  Cleaning Chemicals The choice of chemical/cleaning detergents is determined by the type of food soil likely to occur (dependent on the type of product being processed). In general acid cleaners are used for alkaline soils and alkaline cleaners are used for acid soils. Cleaning detergents/chemicals should meet the basic characteristic/property requirements to be deemed as an efficient cleaner. Efficient cleaners will pose following traits: Emulsification of fat and proteins. Saponification of fats (turn to soap). Readily dissolves in water. Not corrode. Disperse soil particles. Suspend soil particles. Soften and suspend cleaning water. Adequately wet the surfaces of the soil Penetrate to the soil – contact surface thus, dislodging the soil. Suitable to be used in wet cleaning of food contact surfaces.