In hygiene-critical areas, such as those found in the food industry, the demands relating to cleanliness, safety and cleanability are exceptionally high With its Hygienic Design (HD) product range, Rittal – a leading supplier of enclosure solutions – is setting new benchmarks when it comes to material quality, easy cleaning and compliance with technical standards.
This blog post explains why Hygienic Design enclosures from Rittal are the perfect choice for challenging production environments.
What is a Hygienic Design enclosure?
Design and features
Hygienic Design enclosures have been developed specifically for hygiene-critical areas. Such areas are typical in the pharmaceutical, medical technology and food & beverage industries, amongst others.
A Hygienic Design enclosure offers a combination of high-grade stainless steel (1.4301/AISI 304 in the Rittal HD portfolio) and a surface roughness of ≤ 0.8 µm. Rounded edges, sloping surfaces and seamless transitions prevent accumulations of dirt and/or water.
Further features:
- Roof pitch of > 30° to prevent accumulations of liquid
- FDA-compliant seals, resistant to detergents and disinfectants
- Hinges and screws on the inside to ensure a smooth external surface that is easy to clean
- IP 66 and IP 69 protection categories for high-pressure and hot-water cleaning
What is the difference between a Hygienic Design enclosure and a stainless steel enclosure?
Stainless steel enclosures do not all meet hygienic design requirements.
| Feature | Stainless steel enclosure | Hygienic Design enclosure |
| Surface | Brushed, grain size 180 to 400 | Brushed, grain size 400, peak-to-valley height ≤ 0.8 µm |
| Design | Visible screws, hinge welded onto the outside, roof not sloping | HD-compliant design with sloping roof, rounded corners and no dead spaces |
| Cleanability | Can be cleaned | Suitable for frequent cleaning cycles |
| Compliance with standards | Enclosure standards | DIN EN 1672-2:2009 (food safety), FDA-compliant seals, EHEDG |
| Protection category | IP 54-66 | IP 66 / IP 69 |
What standards apply to Hygienic Design enclosures?
Hygienic Design enclosures are subject to a variety of technical standards and guidelines that are intended to ensure they can be used in sensitive areas, such as those found in the food industry. The most important standards are set out below.
DIN EN 1672-2 – European standard for food processing machinery
According to the DIN – the German Institute for Standardisation – DIN EN 1672-2 specifies general hygiene and cleanability requirements for machinery and machine components that are used during food manufacturing and processing This includes machinery for human food and animal feed.
The objective is to eliminate or minimise the risk of contagion, infection, illness or injury arising from food by using machinery with a hygienic design. The standard identifies hazards that are relevant for the use of such food processing machinery. It also describes design methods and provides information that can be used to eliminate or reduce the various risks.
In accordance with DIN EN 1672-2, surfaces must be:
- Corrosion-resistant (made from non-rusting materials such as stainless steel)
- Non-toxic (do not produce substances that are injurious to health)
- Non-absorbent (do not retain substances that can adversely affect food)
- Mechanically resistant (to breaking, chipping and flaking)
No undesirable odours, colouring or flavours must be transferred from the surfaces to the food.
EHEDG guidelines – hygienic design and cleaning validation
The EHEDG (European Hygienic Engineering and Design Group) has published over 50 guidelines that cover various aspects of hygienic design and cleaning. The main guidelines applying to enclosures in the food industry are set out below.
According to EHEDG Guideline 8, “Hygienic Design” includes the following basic criteria:
- Correctly selecting construction materials, especially for product contact surfaces
- Smooth surfaces, including hygienic weld joints
- No gaps
- No protrusions
- No sharp corners
- No T-pieces or dead areas
- Accessibility for cleaning and inspection
- Complete drainability
This guideline applies to the entire food industry. It sets out how equipment should be designed to prevent dust deposits and microbiological risks.
This guideline deals with the hygienic design of equipment that is used in open processes – i.e. where food comes into contact with ambient air. Enclosures, for instance, must be designed in a way that ensures they are not a source of contamination, e.g. with smooth, sloping surfaces that prevent accumulations of dirt and allow water to run off.
EHEDG Guideline 25 defines the hygienic design of electrical and pneumatic components that are used in open food processing areas, including enclosures, control panels and control housings.
This guideline helps manufacturers and plant operators prevent food contamination, reduce cleaning times and increase food safety. It is particularly important for enclosures located in production zones for e.g. meat, milk or bakery products where wet cleaning takes place.
This guideline relates to air routing in production areas. Control cabinets with ventilation or cooling systems must be designed in a way that ensures no contaminated air can get into hygienically sensitive areas.
Although this guideline primarily relates to tubing, it is also relevant for machining stainless steel enclosures. It describes requirements relating to welds to ensure hygienic surfaces.
This overarching guideline describes general hygienic design principles for food factories. It is particularly relevant when designing and positioning enclosures in production areas.
This guideline relates to seals, which can also be found in enclosures (e.g. door seals). It sets out how these seals should be designed and installed to enable cleaning and to ensure they do not pose any microbiological risks.
EU regulations – food hygiene
According to Regulation (EC) No 852/2004, an EU hygiene regulation, HACCP (Hazard Analysis and Critical Control Point) concepts are a legal requirement. An HACCP concept is a systematic process for identifying and controlling potential food safety hazards.
Besides Regulation (EC) No 852/2004, other regulations applying specifically to machinery and equipment that are important for food manufacturers are as follows:
- Regulation (EC) No 853/2004: Lays down specific hygiene rules for food of animal origin.
- Regulation (EC) No 854/2004: Sets out rules for the organisation of official controls on products of animal origin that are intended for human consumption.
- Regulation (EC) No 1935/2004: Relates to materials and articles that are intended to come into contact with food.
Why is a Hygienic Design enclosure important in hygiene-critical environments?
Typical corrosion risks
Enclosures used in the food industry are exposed to particular corrosion risks, as the environment is often damp and hygienically challenging. Typical corrosion risks that can occur are as follows:
- Detergents and disinfectants: When used frequently, alkaline and acidic detergents can attack metal surfaces, especially if the material selected or the coating does not provide adequate protection.
- Food residues and vapours: Organic acids (e.g. acetic acid or lactic acid) from food products can have a corrosive action.
- High humidity: In production areas where steam is generated (e.g. when cooking or washing), condensation can form, which makes corrosion more likely.
- Temperature fluctuations: These fluctuations increase the likelihood of condensate formation inside enclosures.
- Damage to the protective layer: Scratches or knocks can damage the protective coating or stainless steel surface and make corrosion more likely.
- Vibration stresses: Can cause micro-cracks that let in moisture.
- Unsuitable materials: Normal sheet steel is often not sufficiently resistant to corrosion.
- Contact corrosion: Direct contact between different metals can trigger electrochemical reactions.
Dead spaces and areas that are difficult to clean: This can lead to the accumulation of moisture and dirt, which increases the likelihood of corrosion.
How Hygienic Design minimises corrosion risks
Hygienic Design significantly reduces corrosion risks in the food industry, because one of its core principles involves keeping contaminants, moisture and aggressive substances away from sensitive surfaces.
- Prevention of dead spaces: Hygienic Design uses smooth, sloping surfaces and rounded edges to ensure liquids run off and no residues remain.
- Easy cleanability: The surfaces are smooth. Seals form an integral part of the constructions, especially at transition points and openings. This facilitates thorough cleaning and prevents aggressive residues.
- Material: The Hygienic Design concept stipulates the use of corrosion-resistant stainless steel (1.4301 / AISI 304), which is also resistant to cleaning chemicals.
- Protection against mechanical damage: Hygienic Design ensures robust constructions and protected surfaces to prevent damage.
- Preventing condensate formation: Measures such as sloping roofs, ventilation and heating prevent condensate from forming.
How is a Hygienic Design control cabinet cleaned?
Cleaning is a key part of the HACCP strategy. According to the EHEDG, an enclosure with an easy-to-clean design can result in up to a 30 percent reduction in the cleaning time, while still ensuring the same high level of microbial safety.
- Suitable detergents (alkaline or acidic, depending on the type of soiling)
- Soft brushes or cloths so as not to damage the surface
- Clean-in-place (CIP) systems: Especially for permanently installed plant components
- Mobile cleaning systems: Dedicated robots or mobile equipment to clean surfaces
- Plasma-activated water (PAW): Reduces cleaning costs and the use of chemicals
- Fluorescence-based inline contamination detection: Visualises cleanability and documents the effectiveness of cleaning
Benefits of Hygienic Design for cleaning
Th Rittal Hygienic Design range offers well-engineered solutions that have been specifically developed for food industry requirements. With a 30° roof pitch, FDA-compliant seals and protection categories up to IP 69, these enclosures can be cleaned very quickly and reliably – even using high-pressure cleaning and intensive wet cleaning.
No dead spaces
The Hygienic Design approach rules out dead spaces thanks to its rounded edges, smooth transitions and special seals. This prevents micro-organisms and biofilms from forming. Cleaning is more efficient, as there are no hidden nooks and crannies that have to be cleaned manually afterwards.
Self-drainage
Rittal HD enclosures feature a roof that slopes forwards by 30°. This means water automatically runs off after cleaning and no contaminants can settle on the enclosure. The drying time after cleaning is much shorter and the risk of cross-contamination is reduced.
Resistance to chemicals
Rittal Hygienic Design enclosures are made of high-grade stainless steel and have a hygienically brushed surface with a low peak-to-valley height. The FDA-compliant seals that are used are resistant to aggressive detergents and disinfectants. They withstand repeated CIP (clean-in-place) and SIP (sterilise-in-place) processes without losing their functionality. This ensures a long service life and means less time and money is spent on maintenance in hygiene-critical areas.
Tool-free access
Rittal HD enclosures are equipped with hygienic quick-release fasteners that enable tool-free access. These enclosures have deliberately been designed without any screw connections that are difficult to access or any hinges on the outside. This makes for quick and easy inspections, cleaning and maintenance – a clear advantage when it comes to complying with HACCP requirements and documenting hygiene checks.
Summary
Hygienic Design enclosures are essential for efficiency and food safety in hygiene-critical production areas. Their well-engineered construction, high-quality materials and standard-compliant design enable validated cleaning and minimise the risk of contamination.
The comprehensive, tailored Hygienic Design portfolio from Ritta is suitable for all hygiene zones. It is ideal for anyone who needs to be able to rely on quality, safety and efficiency.
FAQs
1. What is a Hygienic Design enclosure, and what is it used for?
Hygienic Design enclosures have been developed specifically for hygiene-critical areas, such as those found in the food, pharmaceutical and medical technology industries. They are easy to clean and meet stringent hygiene requirements.
2. What standards and guidelines apply to Hygienic Design enclosures?
Key standards are DIN EN 1672-2, EHEDG guidelines (e.g. 8, 13, 25, 32, 35, 44 and 48), and EU regulations such as 852/2004 (HACCP), 853/2004 and 1935/2004.
3. What sets Hygienic Design enclosures apart from normal stainless steel enclosures?
They have sloping roofs, rounded edges, no dead spaces, hinges on the inside and FDA-compliant seals. They also comply with protection category IP 66/IP 69 to withstand high-pressure cleaning.
4. Why are Hygienic Design enclosures important when it comes to food safety?
They prevent accumulations of dirt and water, reduce microbiological risks and enable validated cleaning. All these criteria are crucial for HACCP compliance.
5. How does Hygienic Design minimise corrosion risks?
Thanks to corrosion-resistant stainless steel (1.4301/AISI 304), smooth surface finishes, sloping surfaces and a robust design. There are no dead spaces, and condensate formation is reduced.
6. How are Hygienic Design enclosures cleaned?
Manually using suitable detergents or in an automated process using CIP/SIP systems. Innovative methods such as plasma-activated water and inline contamination detection are also possible.
7. What advantages does hygienic design offer when it comes to cleaning and maintenance?
Faster cleaning (takes up to 30 percent less time), tool-free access, chemical-resistant seals and a self-draining design ensure maximum hygiene and efficiency.