INTRODUCTION Ceilings in the food processing plants can be a source of contamination and therefore they should be carefully designed and constructed to prevent adulteration of food products.
Ceilings play an important part in the food processing plants. The type of ceiling used in a particular plant depends on the nature of the food being prepared and/or manufactured. Ceilings must not adulterate food products physically, chemically or microbiologically, as to render food products unsafe for human consumption.
Similarly, ceiling fixtures such as lighting fixtures should not adulterate food products. Lighting fixtures and hence lighting must be arranged in such a manner as to reduce eye strain, maintain and/or increase efficiency and to prevent errors associated with food preparation and manufacture.
The objective of this paper is to present a very concise overview of the main principles associated with ceilings and lighting in food processing plants.
STANDARD REQUIRMENTS FOR CEILINGS IN FOOD PROCESSING PLANTS • Ceilings should be of crack and moisture resistant material. • Ceilings should be painted with light color. • Ceilings in the processing area must be cleared of any fixtures that may contaminate food and equipment. • Horizontal beams, pipes and similar items should be avoided over exposed products and food contact surfaces. • Dropped ceilings should be avoided in processing areas. If false ceilings are needed, they should be sloped at 45 degree angle to the wall. • Proper vents should be installed to prevent moisture accumulation over processing areas and equipment that release steam.
PROPERTIES OF MATERIALS USED IN MAKING CEILINGS • Smooth. • Impervious. • Inert. • Non-rusted. • Non-cracked. • Durable. • Easily cleaned. • Heat resistant. • Water resistant. • Chemical resistant. • Fire resistant. • Corrosion resistant. • Impact resistant.
SOME MATERIALS USED IN MAKING CEILINGS • Stainless steel sheets. • Aluminium sheets. • Wood. • Concrete. • Plastic. • Glasbord. • Sanigrid.
LIGHTING Good lighting is an essential component in all food processing facilities. It is recommended that fluorescent tubes be used for general work. But, care should be taken when using fluorescent light with rotating machine parts. A rotating machine part can appear to be standing still if its velocity matches the number of cycles of the mains electricity running through the fluorescent tube. It is therefore prudent to use normal incandescent lighting for safety reasons.
Lighting fixtures should be constructed in a manner that they do not leak, corrode or cause fires or electrical problems. Since sanitation is critical to food processing industry, a great deal of time is spent washing and sanitizing ceiling, floors, walls and lighting fixtures. It is therefore necessary for these fixtures to be water proof and capable of performing in a wet and damp environment. It is not unusual for high-pressure wash down with hot water and/or sanitation chemicals may approach 1000 psi water pressure.
Lamps used should be suitably protected so that they would not break, for any reason, glass or other matter would not be dispersed throughout the production area. In general a working area should have an illumination of 220 Lux and where close examination is carried out, the illumination should not be less than 540 Lux.
LIGHTING REQUIREMENTS • Lighting sources should be enclosed to avoid falling glasses or other materials from breakage that may be introduced into the food during manufacturing. • Lighting fixtures should be watertight to permit hose down. • Lighting should not be allowed to alter the color of food. • There must be proper lighting at dark corners in the building and at openings into the building to prevent entry and harborage of pest. • In general working areas the lighting intensity should be 220 Lux. In detailed working areas, an illumination of not less than 540 Lux is required.
CONCLUSIONS • Ceilings and lighting are important sources of contamination in all food processing plants. It is therefore essential that great care should be taken in the design of ceilings and only the best materials and competent authority should be used in the construction of ceilings and lighting. • The type of ceiling is dependent on the nature of the food being processed. High temperature environments should use stainless steel coupled with extractor fans. Low temperature environments may use wood or inert plastic polymers. • Lighting fixtures should be positioned for maximum illumination without interfering with the true nature and/or color of food. • Lighting fixtures should be durable enough to withstand cleaning. • Work areas requiring a great detail of examination should use an intensity of 540 Lux, while work areas requiring not so much detail should use an intensity of 210-220 Lux.
REFERENCES Minnesota rules on food sanitation, 2000. Longreen K. Quantity Food Sanitation, John Whiley and Sons Inc., 1980. Fact Sheet, Institute of Food and Agriculture Sciences, University of Florida, 1997. Public Health Service, Food and Drugs Administration, 1998. Pattron, D.D. Food Safety. New York, Scientific Publishers, 2004.
About the Author
Dr Pattron is a Public Health Scientist and Management Specialist in the Ministry of Health, Trinidad.