Glossary and Abbreviations - Unido

educing the likelihood of accidents or operators getting in each other’s way. There should
be enough space for separate storage of raw materials, packaging materials and finished
products.
Fig. 2.1. Basic design for a roots and tubers processing unit
(hand-washing/changing facilities and toilets in another building)
Raw material
store Washing
Processing
area
area
Arrow shows Direction flow of that food
Materials moves around through the room
processing room.
Packaging
Office/testing area
Product store
The arrows indicate the direction that food moves through the processing room.
Roofs and ceilings
Overhanging roofs keep a building cooler, and fibre-cement tiles provide greater insulation
than galvanised iron sheets against heat from the sun. A panelled ceiling should be fitted in
processing and storage rooms, rather than exposed roof beams, which allow dust to
accumulate and fall off in lumps and contaminate products. Beams are also paths for
rodents and birds, creating contamination risks from hairs, feathers or excreta. It is important
to ensure that there are no holes in the ceiling or roof, and no gaps where the roof joins the
walls, which would allow birds, rodents and insects to enter.
Walls, windows and doors
All internal walls should be plastered or rendered with concrete. The surface finish should
have no cracks or ledges, which could harbour dirt or insects. The lower parts of the walls
are most likely to get dirty from washing equipment, and they should either be tiled to at least
1.5 metres above the floor, or painted with waterproof white gloss paint. Higher part of walls
can be painted with good quality emulsion paint if tiling is too expensive.
Natural daylight is preferable to, and cheaper than, electric lighting in processing rooms. The
number and size of windows depends on the amount of money that a processor wishes to
invest, and the security risk in a particular area (windows are more expensive than walls,
especially when security bars or grilles are needed). Storerooms do not need to have
windows. There is a natural inclination for workers to open windows to let in fresh air, but
this provides easy access for flying insects. Windows should therefore be screened with
mosquito mesh. Window sills should be made to slope, to prevent dust accumulating and to
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