Hygenic Design Criteria

This document describes the criteria for the hyginic design of equipment intended for the processing of foods Its fundamental objective is the prevention of the microbia contamination of food products. Such contamination may of course oginate from the raw materials. but the product may also be contaminated with organisms during processing and packaging . If equipment is of poor hygienic design. it will be difficult to clean. Residues (soil) may be retained in crevices and dead areas allowing the micro-organisms which they harbour to survive and multiply. These may then cross contamination the subsequent batches of product

Although a primary objective of design remains that the equipment is able to fulfil its engineering function. sometimes the requirements of hygiene will conflict with this. In seeking an acceptable compromise it is imperative that food safety is never put at risk.

Upgrading an existing design to meet hygiene requirements can be prohibitively expensive and may be unsuccessful and so these are most effectively incorporated into the initial design stage. The long-term benefits of doing so are not only product safety but also the potential to increase the life expectancy of equipment reduce maintenance and consequenty lower operating costs .

This document was first published in 1993 with the intention to describe in more detail the hygienic requemirents of the Machinery Directive (891392/EEC superseded by 98/37/EC: ref. 1). Afterwards pans of it have been included in the standards EN 1672-2 an d EN ISO 1 4159.1