Selecting seals for food contact

Seals in the food industry perform a safety-relevant function within sensitive processes. They prevent the escape of media, protect products from external influences and ensure that production processes take place under consistently hygienic conditions. Even the smallest leaks or material defects can lead to contamination and thus impair the quality, safety and approval status of food.

The requirements for seals in contact with food therefore go far beyond classic sealing tasks. In addition to mechanical resilience, chemical resistance, temperature stability and compliance with legal limits play a central role. Materials must not release any substances into food that affect taste, odour or health safety.

The selection of suitable seals always takes place in the interplay of standards, material properties and the specific application. Production conditions, cleaning processes and the media used determine which solution works reliably in the long term and withstands regulatory requirements.

What is a food-compliant seal? A food-compliant seal consists of materials that are approved in accordance with EU 1935/2004, BfR or FDA and do not release any harmful substances into food. It meets defined limits for migration and remains chemically stable even under temperature, pressure and cleaning.

Relevant standards and regulations at a glance

Several legal and technical requirements apply to seals in contact with food:

• EU Regulation 1935/2004: Regulates materials in contact with food within the EU
• FDA (Food and Drug Administration): Relevant for export or international applications
• BfR recommendations: National guidelines for Germany
• EU 10/2011: Specifically for plastics in contact with food

These sets of rules define limits for migration, ingredients and processing.

Materials for food-compliant seals

The choice of material significantly determines suitability for the respective application:

Material	Properties	Typical applications
Silicone (VMQ)	Temperature-resistant, taste-neutral	Beverages, dairy
EPDM	Good resistance to hot water and steam	CIP/SIP processes
NBR	Oil-resistant	Fatty and oily foods
FKM	High chemical resistance	aggressive media
PTFE	Universally resistant, inert	High-purity applications

Temperature ranges and Shore hardness (guide values):

Material	Temperature range	typical Shore hardness
Silicone	-60 to +200°C	50–70 Shore A
EPDM	-40 to +140°C	60–80 Shore A
NBR	-30 to +100°C	60–80 Shore A
FKM	-20 to +200°C	70–90 Shore A
PTFE	-200 to +260°C	solid (not an elastomer)

The selection always takes place in the context of medium, temperature and mechanical load. Further details on materials can be found in the Sealing materials section as well as under Rubber sheets and Cut pieces.

Selection criteria in practice

The following factors determine the right seal:

• Medium: water, fat, acids or alkalis
• Temperature range: continuous and peak temperatures
• Pressure conditions: static or dynamic
• Cleaning processes: CIP (Cleaning in Place), SIP (Sterilization in Place)
• Mechanical load: movement, friction, compression

Media resistance at a glance:

Medium	Suitable materials
Water / steam	EPDM, silicone
Fats / oils	NBR, FKM
Acids / alkalis	FKM, PTFE
neutral media	silicone, PTFE

The wrong combination leads to premature wear or contamination risks.

Typical applications in the food industry

Seals are used in numerous areas:

• Filling plants
• Piping systems
• Pumps and valves
• Mixing and stirring systems
• Packaging machines

Depending on the area of application, the requirements for material and geometry vary considerably.

Avoiding mistakes in selection

The following problems frequently occur in practice:

• selection without a specific media analysis
• failure to take cleaning cycles into account
• wrong material combination
• missing certificates
• wrong Shore hardness: too soft or too hard leads to leaks
• unsuitable installation groove: wrong geometry reduces the sealing effect
• wrong compression: over- or under-compression shortens the service life

These mistakes lead to production downtime or quality problems.

Tests, certificates and documentation

Food-compliant seals require documented evidence:

• Declaration of conformity in accordance with EU 1935/2004
• FDA approval (depending on the market)
• Test reports on migration
• Material data sheets

These documents are part of quality assurance and are checked during audits.

Individual cut pieces and production

Standard solutions cover many applications. In practice, however, specific requirements frequently emerge that can only be met with custom-made seals. These include complex geometries, special installation situations or increased requirements for pressure, temperature and media resistance.

Individual cut pieces enable exact adaptation to the respective design and avoid typical weak points such as leaks or uneven load. Even small deviations in dimension, material or surface have a direct effect on sealing performance and service life. Production is therefore always based on specific technical specifications that take into account both the installation location and the process conditions.

The choice of manufacturing process also plays a role. Depending on the material and geometry, processes such as waterjet cutting, punching or CNC machining are used in order to achieve clean edges, precise contours and reproducible results. At the same time, this makes it possible to meet hygienic requirements, as smooth surfaces make cleaning easier and reduce deposits.

Particularly in sensitive areas such as food production, this precision leads to more stable processes, shorter downtimes and significantly higher operational reliability over the entire service life of the seal.

Decision logic for quick selection

A clear preliminary selection can be made based on typical operating conditions:

• Fatty media → NBR
• Steam and CIP processes → EPDM
• High chemical load → FKM or PTFE
• Neutral foods and beverages → silicone

This logic does not replace a detailed examination, but offers a quick initial classification.

Typical application examples by industry

• Dairy → EPDM and silicone for steam and cleaning
• Beverage industry → silicone and PTFE for neutral media
• Meat processing → NBR for fatty applications
• Plants with aggressive cleaning → FKM for chemical resistance

Material vs. standard approval

Material	EU 1935/2004	FDA	BfR
Silicone	yes	yes	yes
EPDM	yes	yes	yes
NBR	yes	limited	yes
FKM	yes	yes	limited
PTFE	yes	yes	yes

Service life and maintenance

The service life of a seal is directly determined by the real operating conditions. Temperature profiles, pressure conditions, chemical influences and the intensity of cleaning processes act permanently on the material and lead over time to ageing, embrittlement or loss of elasticity. Particularly in the food industry, frequent CIP and SIP cycles cause additional load, as temperature changes and cleaning chemicals continuously stress the material.

A permanently stable seal is only created when material, design and maintenance are coordinated with one another. Seals usually lose their function gradually before visible damage occurs. The first signs appear in the form of slight deformation, declining restoring force or minimal leaks that intensify during operation.

In the long term, coordinated maintenance has a direct effect on cost-effectiveness, as failures are avoided and plants can be operated stably.

Hygienic design and construction

Increased requirements apply to the construction for use in the food sector:

• avoidance of dead spaces to reduce the formation of germs
• smooth surfaces for easy cleaning
• simple disassembly for maintenance and inspection

These factors increase process reliability and support hygienic production conditions.

Enquiry and implementation

The selection and implementation of suitable seals always begins with a precise analysis of the operating conditions. Medium, temperature, pressure conditions, cleaning processes and installation situation form the basis for every technical decision. The more precisely these parameters are recorded, the more specifically a solution can be developed that works reliably in the long term during operation.

In practice, it becomes clear that blanket solutions rarely meet the actual requirements. Technical coordination in advance makes it possible to align material, geometry and production exactly with one another. This produces seals that meet the requirements of the food industry both functionally and in terms of standards.

In addition to the technical design, the focus is on rapid implementation. Dimensionally accurate cut pieces, coordinated materials and reproducible production ensure stable processes and significantly reduce failure risks.

Have your application checked now: Send us your requirements or drawings for assessment. Based on your operating conditions, you will receive a targeted material recommendation as well as the design of suitable seals for your application.

Frequently asked questions

Which standard applies to seals in contact with food?

The most important basis is EU Regulation 1935/2004. Depending on the material and area of application, BfR recommendations, FDA requirements and, for plastics, also EU Regulation 10/2011 play a role.

Which material is suitable for seals in the food industry?

This depends on the medium and the process conditions. Silicone is often suitable for neutral foods and beverages, EPDM for hot water and steam, NBR for fatty media and FKM or PTFE for chemically demanding applications.

What does food-compliant mean for a seal?

A food-compliant seal consists of materials that may come into contact with food under defined conditions. The material must be such that it does not release any inadmissible substances into the product and meets the hygienic requirements during operation.

Is FDA approval sufficient for use in Europe?

For the European market, compliance with the applicable EU requirements is above all what counts. FDA conformity can additionally be relevant, for example in export projects or international requirements, but does not automatically replace the European sets of rules.

Why do seals fail during operation despite approval?

Approval and practical suitability are two different levels. Many failures are caused by the wrong choice of material, unsuitable Shore hardness, chemically aggressive cleaning, excessively high temperatures or an unsuitable installation situation.

What role do CIP and SIP processes play in the selection?

CIP and SIP processes stress seals through temperature changes, steam and cleaning chemicals. This significantly changes the material load. The seal must therefore be specifically coordinated with these cleaning conditions.

Do custom-made seals make sense in the food industry?

Yes, especially in special installation situations, individual machines or increased hygiene requirements. Custom-made seals improve the accuracy of fit, reduce weak points and support stable processes during ongoing operation.

Which documents should be available for a food-compliant seal?

Depending on the application, declarations of conformity, material data sheets, test reports on migration and, if applicable, further evidence on the materials used are important. These documents are relevant for quality assurance and audits.

When should a seal be replaced?

Replacement is advisable in the case of visible deformation, declining restoring force, cracks, leaks or after defined maintenance intervals. In sensitive food processes, a planned replacement is often more sensible than replacement only after failure.

How do I find the right seal for my application?

The right selection results from medium, temperature, pressure, cleaning, installation situation and the required standards. A technical examination of these parameters creates the basis for a reliable material recommendation and suitable production.

Our rubber sheets

For industry and trade, we offer a wide variety of rubber sheets.

SBR rubber sheet

Our high-quality SBR rubber sheet (styrene-butadiene rubber) is the solution for numerous industrial and commercial applications. This rubber sheet is made from first-class styrene-butadiene rubber and stands out due to its outstanding physical properties.

EPDM rubber sheet

Discover the versatility and reliability of our EPDM rubber sheet, which is made from ethylene propylene diene monomer (EPDM). This high-quality elastomer solution has been specially developed to meet the most demanding industrial and commercial applications.

NBR rubber sheet

The NBR rubber sheet is a high-quality industrial product that has been specially developed for applications requiring excellent resistance to oils, fats and various chemicals.

Viton rubber sheet

The Viton rubber sheet is a high-quality technical product that is used for a wide range of industrial applications. Made from fluoro rubber (FKM), it offers outstanding properties that make it the ideal choice for extreme conditions.

FKM rubber sheet

The FKM rubber sheet is a high-quality technical product that is ideal for use in demanding industrial applications. Made from fluoro rubber (FKM), it stands out due to a variety of outstanding properties that make it the optimal choice for extreme operating conditions.

Silicone rubber sheet

The silicone rubber sheet is a first-class technical product that has been specially developed for applications placing high demands on temperature resistance and flexibility.

PUR rubber sheet

The PUR rubber sheet, made from high-quality polyurethane, is a technically advanced product that has been developed for applications placing the highest demands on abrasion resistance and mechanical resilience.

Neoprene rubber sheet

The Neoprene rubber sheet, made from high-quality chloroprene rubber (CR), is a versatile technical product that is ideal for a wide range of industrial and commercial applications.