Cleanability Critical to Hygiene

Cleanability Photo

Nickel Magazine, Jun. 02 -- European experts in various materials disciplines, including nickel stainless steels, have produced a set of guidelines for the selection of hygienic materials and designs for food-processing equipment.

The Council of Europe's Committee of Experts advises that the guidelines be considered when designing such equipment and when deciding on methods for testing the performance of materials, both metallic and non-metallic.

"For the first time, practical advice is now readily available to designers and fabricators," says Eric Partington, a consultant to the Nickel Development Institute who participated in the production of  Materials for Construction of Equipment in Contact with Food, published by the European Hygienic Engineering and Design Group (EHEDG). "This advice will help ensure the selection of the most suitable and cost-effective material for a defined application."

"The purpose of the new guidelines is to increase designers' and fabricators' appreciation of just how much expertise is available from the supply industries on how materials will behave under a range of operating conditions. Equipment manufacturers who draw upon these resources will be better equipped to avoid technical pitfalls and to produce efficient and hygienic plants with the excellent reliability and lifetime economics for which stainless steels are renowned."

The EHEDG document focuses on the critical stage where designers and operators must jointly anticipate, evaluate and control industrial hazards. In doing so, they must ensure that machinery is capable of being properly installed, operated, cleaned and maintained. In design terminology this process is known as "hazard and critical control point analysis."

According to EC Directive 98/37/EC, machine components that come into contact with a product must be cleaned before use and then regularly restored to an acceptable level of cleanliness by means of disinfecting. Components that come into contact with food should be cleaned by a process known as CIP (cleaning in place), and if this is not possible, they must be easily dismantled and then cleaned. All surfaces and joints must be smooth, since ridges and crevices tend to harbour organic materials.

The hardness and smoothness of stainless steel enable it to resist the adhesion of soils and bio-films, allowing it to be easily cleaned and sanitizing. Indeed, clinical tests prove stainless steel is significantly more hygienic than other food-contact materials. Moreoever, the taste and colour of food products are not affected by stainless steels.

There is a 'family' of stainless steels that provide such a wide range of properties that almost every individual engineering an aesthetic need can be met. Such requirements as strength, corrosion resistance (particularly to strong cleaning agents), formability and weldability generally indicate austenitic stainless steel S30400 or S31600.

Once the food products arrive in the home, stainless steel utensils for food preparation, cooking and serving remain the 'best available' choices for health-conscious consumers.