• The building to house cassava products may be constructed from concrete or bricks and should provide adequate protection against insects and rodents.
• The building should contain a processing hall, an office, a changing room, toilet, ware- housing, and a free lobby.
• For a medium-scale plant, the factory walls could be built to the window level and completed with expanded metal covered with wire mesh to cut down on costs.
• Fixed surfaces of the infrastructure, such as washing troughs and steeping tanks, that come into contact with the processing materials, should have easy-to-clean internal surfaces and be inert to cassava products.
• The surface of walls, partitions, and floors should be made of impervious materials with no toxic effect in intended use and have a smooth surface up to a height appropriate to the operation.
• The floor should be constructed with concrete or terrazzo (if affordable), have adequate surface drainage and be easy to sweep and wash.
• Ceilings and overhead fixtures should be constructed and finished to minimize the build up of dirt and condensation, and the shredding of particles
• Windows should be easy to clean, and fitted with removable and cleanable insect-proof screens.
• Doors should be smooth, non absorbent, and easy to clean and disinfect.
• Adequate means of natural or mechanical ventilation should be provided to minimize airborne contamination, control ambient temperature, odors, and humidity.
• Lighting fixtures should, where appropriate, be protected to ensure that food is not contaminated by breakages.
• An adequate supply of potable water with appropriate facilities for its storage and distribution, should be available, whenever necessary, to ensure the safety and suitability of food.

Material handling
Potential sources of contamination from the environment should be considered. In particular, primary food production should not be carried out in areas where the presence of potentially harmful substances would lead to an unacceptable level of such substances in food.

Raw materials or ingredients should, where appropriate, be inspected and sorted before processing. Stocks of raw materials and ingredients should be subject to effective stock rotation.

Producers should as far as practicable implement measures to:

• Control contamination from air, solids, water, feedstuffs, fertilizers (including natural fertilizers), pesticides, veterinary drugs, or any other agent used in primary production.
• Control plant and animal health so that it does not pose a threat to human health through food consumption, or adversely affect the suitability of the product.
• Protect food sources from faecal and other contamination.

During raw material handling, storage and transport, procedures should be in place to:

• Sort food and food consumption ingredients to segregate material which is evidently unfit for human consumption.
• Dispose of any rejected material in an hygienic manner.
• Protect food and food ingredients from contamination by pests, or by chemical, physical, or microbiological contaminants, or other objectionable substances.

Cleaning maintenance and personnel hygiene procedures should be in place to ensure that:

• Any necessary cleaning and maintenance is carried out effectively
• An appropriate degree of personal hygiene is maintained.

Process control

Equipment must be designed to dry, fry, cool or store food to achieve the required food temperature as rapidly as necessary in the interests of food safety and suitability, and to maintain them effectively.

Equipment is designed to allow temperatures to be monitored and controlled. Where necessary, equipment should have effective means of controlling and monitoring humidity, airflow, and other characteristics likely to have a detrimental effect on the safety and suitability of food.

These requirements will ensure that:

• Harmful (cyanide or butanoic acid) or undesirable micro-organisms or their toxins (mycotoxins), are eliminated or reduced to safe levels or their survival and growth are effectively controlled.
• Where appropriate, critical limits established in plans based on Hazards Analysis Critical Control Points (HACCP) can be monitored.
• Temperatures and other conditions necessary to food safety and suitability can be rapidly achieved and maintained.

Facilities for personnel and personal hygiene
Facilities should be available to ensure that an appropriate degree of personal hygiene can be maintained and to avoid contaminating food. Where appropriate, the facilities should include:

• Adequate means of hygienically washing and drying hands, including wash basins, and a supply of hot and cold water.
• Lavatories of an appropriate hygienic design.
• Adequate changing facilities for personnel.

Such facilities should be suitably located and designated. Facilities for cleaning such as hoses should be provided for cleaning the washing trough, hydraulic press, hammer mill, dryer, steeping tanks, other equipment, and the floor. Taps should be installed at the tops of the washing trough and steeping tanks. Also outlets such as stoppers for easy draining at the top and base of each facility should be installed.

People who come directly or indirectly into contact with food will not be likely to contaminate food by:

• Maintaining an appropriate degree of personal cleanliness.
• Behaving and operating in an appropriate manner.
  Note: Workers who are ill, and especially if suffering from diarrhoea or skin infections, should not under any circumstances be allowed to handle food.

Visitors to the food manufacturing, processing, or handling areas should, where appropriate, wear protective clothing and follow the other personal hygiene provisions in this section.

A changing room should be provided for staff to change into factory coats.The use of factory coats will minimize the introduction of undesirable micro-organisms from soil and dust carried on the clothing of staff when they report to work.

Drainage and waste disposal

Adequate drainage and waste disposal systems and facilities should be provided. They should be designed and constructed to avoid any risk of contaminating food or the potable water supply.
Storage facilities

Adequate facilities should be provided for the storage of food, ingredients and non food chemicals (e.g, cleaning materials, lubricants, fuels).Where appropriate, food storage facilities should be designed and constructed to:

• Permit adequate maintenance and cleaning.
• Avoid pests and harbourage.
• Enable food to be effectively protected from contamination during storage.

Where necessary, provide an environment which minimizes the deterioration of food (e.g. by temperature and humidity control).

• Peelers
• Washers
• Graters
• Pressers
• Extruders
• Millers
• Dryers
• Pelletizers
• Sealers
• Packing machines