Innovations in hygienic design are changes to materials, surfaces, seals and component geometry that make food-processing equipment easier to clean, harder to contaminate and longer-lasting. Hygienic design is central to the safety and quality of food, and EHEDG (the European Hygienic Engineering & Design Group) develops guidelines and certifies specific designs that meet them. As requirements and cleaning demands rise, component design keeps moving – but not every "new" feature reduces risk.
This page looks at the main directions of change and gives a method to judge them. The basic principles are covered in hygienic levelling feet: clean design from the ground up and the cost side in EHEDG certified design and energy savings.
What EHEDG certification actually covers
A common misunderstanding is that EHEDG certifies parts or materials in general. In fact:
- EHEDG certifies specific equipment and component designs – for example a particular valve, pump, seal arrangement, bearing unit or levelling foot – after review against its guidelines.
- For most closed equipment, certification also requires a cleanability test.
- Certified designs are listed in the EHEDG public database; certificates run on a five-year cycle.
- Certification is voluntary. "Designed to EHEDG guidelines" is not the same as certified.
So a component can be innovative and hygienic without being certified – and a certificate for one design does not cover the rest of a range. For examples of certified designs, see EHEDG components. Background: everything you want to know about EHEDG certification.
Main directions of innovation in hygienic components
| Area | What is changing | Hygienic benefit | What to verify |
|---|---|---|---|
| Surface finishes | Electropolishing, laser polishing, controlled mechanical polishing | Lower roughness, fewer places for residue and bacteria | Measured Ra, finish of welds and edges |
| Materials and coatings | Higher-alloy steels, wear-resistant coatings, engineering polymers and composites | Longer life in wear and corrosion conditions | Food-contact declaration, chemical and temperature resistance |
| Sealed bearings | Improved seal materials and geometries, sealed-for-life lubrication, closed covers | Keeps water and detergent out, removes relubrication | Seal compatibility, suitability for cleaning method |
| Levelling feet | Sealed spindles, no exposed thread, self-draining bases | Removes crevices at floor level | Seal design, load and slope rating, certificate if claimed |
| Sensors and monitoring | Condition monitoring of bearings, temperature, cleaning parameters | Earlier maintenance, verified cleaning | Cleanable sensor housings and cable entries |
| Sustainability | Longer component life, designs that need less water and chemical to clean | Fewer replacements, lower cleaning burden | Evidence for claims, not general statements |
Surface finishes
Surface finish decides how easily soil releases. Surface roughness Ra is the average deviation of the surface profile from its mean line; EHEDG guidance gives Ra ≤ 0.8 µm for product-contact surfaces, and 3-A uses the same reference – see surface roughness Ra for food contact.
Electropolishing removes a thin surface layer electrochemically, lowering roughness peaks and improving the passive layer. Laser polishing melts and smooths a thin layer locally. Both can make surfaces easier to clean, but neither fixes poor geometry: a polished crevice is still a crevice. Specify the required Ra, the area it applies to and how it is measured.
Materials and coatings
Stainless steel remains the default for hygienic components because of its corrosion resistance and cleanability. The search is for materials that last longer under wear, chlorides or aggressive cleaning while staying cleanable:
- Higher-alloy stainless steels for chloride-rich environments – see AISI 316L vs AISI 304.
- Wear-resistant coatings on shafts and wear surfaces – check adhesion, food-contact status and resistance to cleaning chemicals.
- Engineering polymers and composites for housings and bases – no corrosion, low weight, but lower load and temperature limits.
For any new material, ask for a declaration of compliance (EC 1935/2004 in the EU; EU 10/2011 for plastics; FDA 21 CFR 177.2600 for rubber in the US) and test it against your actual detergents, disinfectants and temperatures.
Sealed bearings
Unsealed bearings in wet zones let water, detergent and product in and lubricant out – the inside becomes a harbourage point (a place where residue and microorganisms survive cleaning). Sealed bearing technology is already common in hygienic equipment; development continues on:
- Seal materials and geometry: elastomer and hybrid seals that keep contaminants out with acceptable friction. Check elastomer compatibility – EPDM, FKM, VMQ and NBR each behave differently with chemicals and temperature.
- Sealed-for-life lubrication: removes relubrication, a common contamination and error source. Where relubrication is still needed, use food-grade (H1) lubricant.
- Housings and covers: stainless or composite housings with closed end covers and smooth, self-draining outer shapes.
Ingress ratings such as IP67 (immersion test) or IP69K (high-pressure water jet test, ISO 20653) describe water ingress, not cleanability; see IP68 or IP69K in hygienic zones. For selection of complete units, see pillow block bearings: the complete guide.
Levelling feet
Levelling feet support equipment and keep it stable, but they also decide how well the floor zone under a machine can be cleaned. Design improvements include:
- Protective seals and sleeves that stop debris and cleaning fluids entering threads and joints.
- Easier height adjustment without exposing thread, so the machine can be re-levelled after cleaning or relocation.
- Corrosion-resistant materials: stainless steel bases and spindles, polymer or composite base plates with documented food-contact rubber pads.
For the detailed design and selection, see hygienic machine leveling mounts.
Sensors and connected components
Sensors that monitor bearing temperature, vibration or cleaning parameters (temperature, flow, conductivity) can support predictive maintenance and verify that cleaning ran as specified. Two conditions apply:
- The sensor must be hygienic itself: smooth sealed housing, no crevices at cable entries, cables routed so they do not create dead spaces.
- The data must change a decision: a sensor that nobody acts on adds a cleaning point and a failure point without reducing risk. For a fuller treatment, see automated hygienic components in food manufacturing.
How to evaluate a new hygienic component feature
- Cleanability: does it remove crevices, dead spaces or exposed threads? Is it self-draining? Does it fit your cleaning method (CIP, COP, foam, high-pressure washdown)?
- Materials: is there a declaration of compliance? Does it resist your chemicals and temperatures?
- Evidence: is there a certificate for this specific design, test data or field experience in a comparable application?
- Lifecycle: are spares and seals available? Can maintenance staff service it without creating new hygiene risks?
- Comparison: is it better than the current part on these four points – not just newer?
Example: replacing open bearings on a washdown conveyor
Assumptions (illustrative): a meat-plant conveyor with cast iron bearing units that are relubricated weekly; daily foam cleaning with chlorinated detergent.
- Option considered: sealed-for-life stainless bearing units with closed covers.
- Cleanability: smooth housing, no grease nipple, closed shaft end – passes.
- Materials: stainless housing and insert; seal material checked against the detergent – passes if confirmed.
- Evidence: supplier test data or certificate for the specific unit – request it.
- Lifecycle: no relubrication, so less hands-on contact with the unit; replacement planned on condition.
Sustainability claims
Longer-lasting hygienic parts, fewer replacements and designs that clean with less water and chemical do reduce environmental impact. Treat general claims such as "eco-friendly" or "sustainable" with care: ask what was measured, against what baseline, and whether the evidence applies to your application.
