Aluminium sheets in food technology – hygienic and robust?

Aluminium sheets are increasingly used in the food industry as an alternative to classic materials such as stainless steel. Their low weight, their corrosion resistance and their good machinability make them interesting for many hygienically sensitive applications. But are they really suitable for direct or indirect contact with food?

Suitability of aluminium sheets for food engineering

In food engineering, materials are required that can be cleaned easily, do not release any harmful substances and are permanently resistant to moisture, acids and cleaning agents. Aluminium can meet these requirements – provided the right alloy and surface treatment are chosen.

In particular anodised aluminium sheets are regarded as hygienically safe, since the pore-free oxide layer provides a smooth, resistant surface. Untreated aluminium is also permitted in certain applications, but is subject to stricter requirements regarding processing and care.

Hygienic properties: cleaning, surfaces, germ behaviour

A central criterion in food-processing operations is cleanability. Aluminium surfaces must be smooth, crack-free and resistant to cleaning chemicals in order to avoid the formation of biofilms and germ niches.

Anodised aluminium sheets have advantages here: the anodised layer is chemically stable, corrosion-resistant and can be cleaned without difficulty with suitable cleaning agents. However, it is important that no micro-scratches or damage occur, as these can represent hygienic weak points.

Which aluminium alloys are food-safe?

Not every aluminium alloy is automatically suitable for use in the food industry. The following are regarded as particularly suitable, e.g.:

• EN AW-1050A (Al99.5) – very pure, soft aluminium alloy
• EN AW-5005 – often anodised, good corrosion resistance
• EN AW-5754 – robust, seawater-resistant, easy to clean

The choice of alloy should always be matched to the specific application. Consultation with the manufacturer or supplier is mandatory for sensitive applications.

Surface treatment: anodising, films, coatings

Anodising

Anodising (anodic oxidation) creates a hard, dense oxide layer that is corrosion- and abrasion-resistant. This layer is pore-free, easy to clean and prevents the release of aluminium ions – ideal for hygienic applications.

Film coating

In film coating, a temporary protective film is applied that protects aluminium sheets from contamination or damage during transport and installation. The film is removed before commissioning and therefore plays no hygienic role in operation itself.

Powder coating or painting

Coated aluminium sheets are only conditionally food-safe. For a powder coating to be permitted in food engineering, it must meet special requirements and certifications (e.g. FDA-compliant). For direct food contact, this variant is rarely used.

For direct contact with food, anodised aluminium is usually the safest option.

Typical applications of aluminium sheets in food processing

Aluminium sheets are used in food engineering, among other things, as:

• Cladding for machines and systems
• Covers and work surfaces (indirect contact)
• Wall cladding and ceiling panels in cleanrooms
• Partition walls and protective covers
• Transport and storage containers (with special design)

For direct food contact, additional requirements apply to the material, e.g. conformity with food legislation.

Relevant standards and regulations

The following directives and standards are relevant for aluminium in food engineering:

• EU Regulation 1935/2004/EC: framework provision for materials in contact with food
• Regulation (EU) No. 10/2011: specifically for plastics, but partly also relevant for coatings
• FDA compliance (USA): optional for international supply chains
• EN 602: hygiene requirements for food machinery

Cutting to size and processing must also be carried out under hygienic conditions to ensure conformity.

Comparison: aluminium sheet vs. stainless steel in food engineering

Feature	Aluminium sheet (anodised)	Stainless steel (e.g. 1.4301)
Weight	Significantly lighter	Heavier
Cleanability	Good, but more sensitive to scratches	Very good, robust
Corrosion resistance	High (with anodised surfaces)	Very high
Price	Cheaper	More expensive
Direct food contact	Only certain alloys	Broad approval, standard choice

Aluminium can replace stainless steel in many areas, but should be chosen with care.

Recommendations for planning, cutting to size and installation

Anyone wishing to use aluminium sheets in food-engineering systems should observe the following:

• Use only suitable alloys and surfaces
• Ensure residue-free cleaning and smooth edges
• Prefer anodised sheets, no open cut edges in wet areas
• Do not install with rusting screws or contact corrosion (steel + aluminium)
• Hygienic planning of joints, transitions and fastenings

For CNC cut pieces, drillings or special shapes, collaboration with an experienced supplier is advisable.

Conclusion: when are aluminium sheets a hygienically sensible solution?

Aluminium sheets can be a suitable solution in food engineering – in particular for cladding, surfaces with indirect contact or lightweight construction solutions. For direct food contact, careful selection of the alloy and surface is required. Anodised aluminium sheets offer a good combination of hygiene, functionality and cost-effectiveness.

FAQ

Are anodised aluminium sheets approved for food contact? Yes, certain anodised aluminium sheets are regarded as food-safe, provided they have been produced according to the relevant standards.

Which is better: aluminium or stainless steel in food engineering? Stainless steel is more robust and more broadly approved, aluminium offers advantages in weight and cost – but is more sensitive.

Which cleaning agents may be used on aluminium? No strongly alkaline or strongly acidic agents. Neutral or mildly alkaline cleaners with low abrasive effect are best.

How can aluminium sheets be installed hygienically? With rust-free screws, concealed fastenings and cleanly deburred cut edges. No open joints in wet areas.