Hygienic Designing of Food Facility
To ensure food safety and sanitation, it is mandatory to have hygienic food designing of food factory. Hygienic food factory design provides defense against external factory hazards and internal factory hazards by removing harborage sites. Man- material movement can be restricted and can be maintained in the pant to check the flows of people, product, packaging material, air and wastes, to prevent cross-contamination. Security against deliberate contamination or sabotages can also be achieved by restricting the entry and people movement in accordance to the working. Hygienic food factory design provides food safety by providing barriers to food contaminations. This can be achieved by proper check at outside premises level, closing of factory buildings levels and by ssegregating the restricted areas.
Components for Hygienic Designing
- Appropriate Layout: Having an appropriate layout is very important and design of the food factory must be adapted to the hygienic requirements of a given process, packaging or storage area. Movement of raw materials and ingredients should move from the ‘dirty’ to the ‘clean’ areas and reverse should be the flow in case of food waste and discarded outer packaging materials. There are always chances of expansion of business and hence the building and its food processing support systems should be designed so they can either be expanded, or another building and/or utilities can be added.
- Pest Prevention: To prevent any type of pest and rodent entry in plant it is recommended the plants are built at higher level than the ground level. Number of loading docks should be kept as minimum as possible with no direct opening in the exterior environment unmonitored. Every entry from exterior environment or from medium hygienic area to high hygienic area need to be installed with air curtains, automatic doors, strip curtains and to maintain required air pressure for preventing pest. Intruding insects can be attracted & killed within the factory by strategically positioned UV light electric grids or adhesive glue board traps. It should be noted that glue pads should be used in production area where product comes in contact with environments.
- Interior Hygienic Design Construction Materials: Construction materials for equipment and utility piping should be hygienic (smooth, non-absorbent, non-toxic and easily cleanable), chemical-resistant (to product, process chemicals, cleaning and sanitizing agents), physically durable (unbreakable, resistant to steam, moisture, cold, abrasion and chipping) and easy to maintain. Material used for construction of area where product can come to contact with, should be constructed with material of superior quality. Harmful material like lead, mercury and cadmium should not be used in any material for construction of food factories, only alloys for food contact can contain aluminum, chromium, copper, gold, iron, molybdenum, nickel, platinum, silver, titanium, zinc, carbon, etc. To prevent any type of flaking and chipping of paints, it is recommended to not paint the ceiling and adjacent walls of production area and area with high water usage area, with normal paints. Epoxy should be used as coating material in such area.
- Integration of Piping: Utility piping in technical corridors or zone H areas should be integrated into wall compartments or the ceiling. If this is not possible, it is recommended to use open racks, fixed to the ceiling, or walls and columns close to the ceiling and sufficient clearance must be provided between pipe runs and adjacent surfaces so that both are readily accessible for cleaning and maintenance. The pipe racks must be designed hygienically to minimize the presence of horizontal ledges, crevices or gaps where inaccessible dirt can accumulate. Use of minimum amount of utility piping should be done and all piping should be directly routed from service rooms to process areas and should always be logical and simple.
In process area, hot water and process steam piping, standing “pools” of liquid that can support the growth of microorganisms must be avoided. To remove condensate, steam traps should be located at all low, convenient points along any extended pipe length. Steam purges for relief of steam condensate in a drain should be closely connected to that drain. Discharge of condensate from the system should be via an air break to prevent back-siphonage. Neither process nor utility piping should have dead legs. All tapping to the equipment’s should be preferred to be vertical as is more hygienic than the horizontal one. To encourage thorough cleaning around and between, piping should be installed at least 6 cm from walls and floors and also piping in corners should be avoided, as it hampers thorough cleaning.
- Hygienically Designed Electrical Accessories
To make connections between different processing units in adjacent rooms, use hygienically designed transfer panels. Interconnection between the different ports should be made with sanitary U- and J-bends. Piping behind the transfer panel and the panel ports must be sloped to ensure proper drainage of residual liquid toward a drain pan. All ports should be capped when not in use to prevent any potential spill or contamination. In the food contact area, electric components must always be enclosed in junction boxes, casings, closed cable housings, cabinets, etc. or should be installed in non-product contact zones or in technical corridors.
Lighting must illuminate horizontal and vertical working surfaces evenly, without causing glare and at an intensity of about 300–500 lux at normal working height. Preference should be given to lighting mounted on ceilings rather than on walls, because process equipment, storage racks, etc. can form shadows that make cleaning and inspection of floor, walls or ceilings difficult. For the same reason, overhead piping may not obstruct lighting. To avoid projections that accumulate dust, they can be built into the ceiling or wall with a hermetically closed seal.
- Balanced Air Supply and Exhaust System
Exhaust systems should have sufficient capacity to remove excess heat, dust, vapor, aerosols, odors and bio-burden from process rooms. The supply of filtered air in the room by the HVAC system must be large enough, otherwise the exhaust system will attempt to draw the required amount of air from adjacent less clean areas through doorways and windows. With all exhaust fans located outside the building to maintain a negative pressure in the portion of the duct system located within the building