By Izak Hofmeyr
The hygienic design of dairy equipment was the subject of discussion during a recent webinar hosted by the Dairy Standard Agency (DSA) in collaboration with the Food Risk Forum. The speaker was Peet Grobler, chairperson of the Southern African section of the European Hygienic Engineering Design Group (EHEDG), as well as head of hygiene and food safety at the OFT Group and sales manager at Sentratek.
The correct and hygienic design of dairy equipment and infrastructure is aimed at preventing biological, chemical or physical contamination of the product or material by means of penetration, accumulation or growth.
Such a design has the so-called hazard analysis critical control points (HACCP) food safety management system as its starting point – this system minimises foreseeable hygiene risks and supports the implementation of prevention and mitigation measures such as cleaning and disinfection.
Grobler discussed ten design principles that influence the risk management process:
#1 Understand your risk
Machine surfaces can be direct or indirect. Direct surfaces are in direct contact with the product, whereas indirect surfaces are equally important because there is always a risk of contamination.
It is essential to understand the type of risk, of which there are three: physical, biological, and chemical. A holistic approach must be taken to determine and manage the possible origins of these risks.
#2 Cleaning down to the microbial level
In terms of cleaning, there are two processes, On the one hand there are open surfaces, which include hard-to-reach places; on the other you have closed surfaces such as tanks and pasteurisers. Both present different challenges. Therefore, the design of equipment must allow for effective cleaning and limiting of bacterial penetration, survival, and reproduction.
#3 Suitable material
The material utilised for the manufacturing of equipment must be fully compatible with the product, the environment, cleaning requirements, and the chemicals and cleaning methods required. Joints in particular should be easy to clean to limit the build-up of debris. Surfaces should be smooth and even for effective cleaning and to minimise debris build up. They should be compatible with the environment and the type of chemicals used for disinfection.
#4 Drainage
All equipment and pipes should be self-draining and easy to clean inside and outside. Horizontal surfaces should be avoided, and surfaces should have an incline away from the product.
#5 Accessible equipment
All components must be easily accessible, and equipment should be easy to disassemble and reassemble. This especially pertains to surfaces that come into direct contact with the product. Quick and efficient access contributes to the efficiency of the facility and reduces the risk of contamination.
#6 Seals and joints
Joints between pipes, tanks and other components should be tight but easy to clean. Screw threads can harbour bacteria and should therefore be avoided. Specially designed hygienic joints and clamps ensure a tight seal and prevent products or cleaning products from leaking and causing cross-contamination.
#7 Openings
The design should be seamless, without rough joints, cavities or other places in which debris can collect. Smooth surfaces are essential for simplifying the task of cleaning. Welds should be smooth and even so that no debris can be trapped.
#8 Cavities
Avoid inaccessible, difficult to clean cavities by avoiding closed spaces or designing them to allow easy access for cleaning.
#9 Avoid cross-contamination
The design of equipment should aim to avoid cross-contamination between raw and processed products by incorporating separate channels, especially if products are mixed, extracted or packaged in the open air. This includes effective cleaning methods and separate cleaning systems for raw and processed products, combined with a comprehensive traceability system for each stage of the processing process.
#10 Documentation, inspection and validation
All hygienic design principles must comply with regulatory standards. Hygienic design risk management in a dairy facility, he said, is the foundation of product safety, quality, and consumer health. By focussing on the principles of hygiene, material selection, ease of cleaning, proper drainage and prevention of cross-contamination, processors can significantly reduce the risk of contamination and spoilage.
These principles ensure that dairy products are safe and meet the highest standards. There are a host of guidelines that facilitate risk identification and mitigation, he added. EHEDG, for example, has not only formulated guidelines for risk management, but regularly offers advanced design courses and has a list of EHEDG-certified equipment.
For more information about the Dairy Standard Agency’s services and webinars, visit www.dairystandard.co.za or contact Jompie Burger at email jompie@dairystandard.co.za or Jacqueline Odendaal at jacqueline@dairystandard.co.za
