Page 36 - Food&Drink Magazine October 2021

HYGIENE & SAFETY
Designing holistic hygiene
Hygienic design is a term used freely in the manufacturing sector. HACCP International technical director Martin Stone explains why he prefers a more holistic definition with key criteria and considerations.
MY role with HACCP International involves the review of equipment specifically developed for use within the food industry. Much of this equipment is produced by some of the world’s leading manufacturers and I often hear the term ‘hygienic design’ tossed around. So, what exactly does it mean and why do we want it?
In its most basic form, hygienic design means easy to clean. But I like to consider a more holistic meaning where it means that all food safety hazards (including chemical, physical and microbiological) have been engineered to an acceptable level of likelihood occurrence, when used as designed (and sometimes when not).
Let’s have a look at some of the key criteria associated with hygienic design applied to a unit of equipment and what considerations should be undertaken when assessing hygienic design.
SURFACE MATTER
Surfaces should be considered in terms of being food contact
or non-contact and there is an obvious gradient of risk in these cases. The material itself needs to be durable and impervious to food and liquid solutions.
Any coatings on the material such as plating or paints should be scrutinised carefully, as these elements are known to wear and/or chip off into the food stream.
indicator of how easy it is to clean. Quantitative measurements such as Ra are often used to describe roughness of a surface and should be considered based on intended usage of the surface. Ra is typically measured in microns (one millionth of a metre) and represents the average rise or fall of troughs
36 | Food&Drink business | October 2021 | www.foodanddrinkbusiness.com.au
“ At temperature extremes that can occur through washing or other uses, the materials may behave differently, and risks may increase.”
When considering coatings, ask where a chip of that coating would end up if it was dislodged during operation or cleaning. The surface should not provide for any compound migration into the food and must be resistant to both the food and chemicals used to clean the surface.
Surface roughness is often considered, particularly for food contact surfaces, and is an
and peaks from a mean line. That means, the average distance between a trough and a peak of a material with a Ra of 0.5 micron is one micron. The significance of this can be realised when seeing that a single bacterium is around one micron wide. Consequently, the Ra recommendation for food contact surfaces is typically below 0.8 microns.