Hygiene risk assessment protects employees and consumers

Hygienic design refers to the so-called cleaning-friendly design of production facilities, components and parts. The materials used and their combination, a geometric design, connection solutions, components, manufacturing processes and surface coatings play a role.

Hygienic design aims to reduce or eliminate hygiene risks. These include hazards for employees during the production process or hazards that are passed on to the consumer through the finished product. They are divided into three categories: firstly, biological hazards such as microorganisms or the toxins they excrete, and secondly, chemical hazards due to contaminated materials, unsuitable lubricants or residues of cleaning agents and disinfectants. The third category is the hazard to the consumer due to physical jumping, if foreign bodies, for example metal splinters, have got into the product.

So it is not only manufacturers of machines, systems and equipment who have to take hygienic design into account - it also plays a role in the operation of the system and the process area, affecting production and cleaning management. The importance of Hygienic Design cannot be ignored: If mistakes happen when assessing hygiene risks, products can quickly be compromised and consumers put at risk. If the design of machines proves not to be hygienic and people are harmed as a result, mistakes can be ruinous for the operators.

Hygiene risk assessment: basis for hygienic design

The basis for the hygienic design of a machine or component is the hygiene risk assessment: it reveals potential hazards and allows the extent, frequency and probability of occurrence of damage to be calculated.

Manufacturers of machines and apparatus that may pose a hygiene risk must carry out the hygiene risk assessment when planning and constructing or significantly modifying a machine. The sectors affected are food production and processing, pharmaceuticals and cosmetics, and medical and biotechnology.

Components or spare parts that come into contact with food in production must also meet hygienic standards, which is important for manufacturers when retrofitting or purchasing parts, for example. Their intended use must provide for application in sensitive areas. In practice, however, it often turns out that plastic materials that come into contact with sensitive substances such as food are not designed for this purpose because there is no declaration of conformity or a faulty declaration of conformity in accordance with Regulation (EU) No. 10/2011. Regulation (EC) No 1935/2004 sets out the essential requirements for materials and articles intended to come into contact with food. For other materials such as stainless steel, the declaration of compliance is voluntary: they are covered by the good manufacturing practice requirements of Regulation (EC) No 2023/2006.

Regulations and laws for hygiene risk assessment

Annex I No. 2.1. of the Machinery Directive stipulates that machinery, parts and components must be designed in such a way as to exclude any risk of infection. It is concretised by the C standard EN 1672-2, Food processing machinery - General principles for design - Part 2: Hygiene and cleanability requirements. In addition, EN 14159 Safety of machinery defines hygiene requirements for the design of machinery, hygiene requirements that are not covered by EN 1672-2.

In addition, the EHEDG guidelines (guidelines of the European Hygienic Engineering and Design Group) are used in practice, even though they are not legal obligations. They concretise the guidelines for individual components.

Hygiene risk assessment in practice

When considering hygiene risks, the design and construction of the machine, its surface structure and materials science must be taken into account.

At the beginning of the planning and even before the construction of a machine, clarity about the intended use is required for the hygiene risk assessment: What substances does it process, what are the environmental influences, how high is the temperature, the humidity? Is it an open or a closed process? What type of product is being produced - a raw material or a product ready for consumption - and at what stage of processing?

In addition, the division into a product-contacting area, spray area and the non-food area of a machine takes place in the planning and design phase. This results in requirements for the construction materials. Among other things, these must be corrosion-resistant and non-toxic and must not form cracks. Companies should keep an eye on whether the materials of their machines are suitable for their intended use - knowing the material number helps here.

The holistic approach in the design phase is so important because it is difficult to make design changes to the equipment afterwards. In this way, corners and edges can be avoided from the outset, cleaning agents and aerosols can flow off or escape and easy cleanability is ensured. In closed systems, where foodstuffs are processed and transported in pipes and tanks without contact with air, complete drainage of liquids is guaranteed. If residual liquid remained in the system, the pipes would have to be rearranged or drains constructed.

In addition to looking at the machine, it is helpful if manufacturers not only know the food that is to be produced, but also have knowledge of the process of further processing. This is because different process steps have different effects on possible risks. The hygiene risk results from the machine and the processing step. It is therefore important to take a holistic view. The details matter, because hazards are not always obvious at first glance.

Once the hygiene risk reduction has been carried out, the hygiene risk assessment also includes the question of whether a hygiene risk results from protective measures to minimise the safety risk at the machine. If this is the case, it must be examined which hazards are present, whether new risks result from the protective measures or whether old risks are increased. This is followed by a weighing of the risks - in the best case, it should be possible to minimize both. Because safety and hygiene do not have to be contradictory. Safety measures do not necessarily have to increase the hygiene risk, and vice versa. Here it is advisable to pay attention to hygienic design when selecting the safety devices, for example by making position switches cleanable and providing splash water and dust protection.

At the end of the hygiene risk assessment process, the measures are verified with visual inspections, measurements or analyses such as fluorescence tests and the necessary documentation. Finally, the operating instructions include which cleaning and disinfection measures are recommended, when and in what concentration. If components have to be disassembled for cleaning, this procedure is also described.

Conversion of machines

If a machine is modified, it must already be checked during the planning of the modification whether this results in increased risks for hygiene and safety. For example, if a machine is converted from manual to mechanical loading, surfaces must be designed so that liquids can drain off by themselves. Components with lubricants that are not suitable for food cannot be installed, and control cabinets also pose a hygiene risk.

If the conversion means a significant change to the machine, the operator becomes the manufacturer. This requires a new hygiene risk assessment. External companies can provide advice here.

Conclusion

Hygiene risk assessment should be considered at the design stage of a machine, as subsequent changes are expensive and not easy to implement. Although it is a mandatory task for manufacturing companies, it can bring significant added value: Not only does it contribute decisively to product safety and production efficiency when machines are designed from the outset in such a way that risks are minimized and operators have fewer weak points to monitor. It also improves sustainability by helping to reduce the consumption of resources, for example when machines are designed from the outset so that fewer cleaning agents and disinfectants are required.