Standard & approval
NSF
Food contact according to NSF/ANSI 51
NSF tests and lists materials, components and equipment for food contact.
Field
Food
Standard
NSF/ANSI 51
Origin
USA
Zones
Food · Splash · Non-food
Overview
NSF/ANSI 51 sets out requirements for materials and components installed in food processing equipment. The assessment covers composition, migration/extraction, temperature and cleaning resistance, and suitability for defined hygiene zones. In addition, NSF Nonfood Compounds registration exists for auxiliary substances with incidental food contact.
Which of our products require NSF conformity?
- Moulded articles and O-rings in filling/dosing units, valves, pumps
- Flat seals in pipe/equipment flanges, sight glasses, heat exchangers
- Hoses/hose rings for conveying and static applications
- Lid/enclosure seals on machines with wet cleaning (CIP/SIP)
Food zones and hygiene areas (NSF/ANSI 51)
| Zone | Description | Example | Material/design requirements |
|---|---|---|---|
| Food zone (direct/indirect) | Direct or indirect food contact | Seals in valves, filling lances, product lines | Food-grade material, limited migration, chemical/thermal resistance, smooth cleanable surface |
| Splash zone | Contact with food splashes/cleaning | Enclosure/lid seals in the splash area | Resistance to cleaning/disinfection, tight design, no crevices |
| Non-food zone | No regular food contact | Sealed electrical compartments, control panels | Primarily IP protection; less strict on the material side, but still hygienic |
Which requirements must be met?
- Material conformity: food-grade formulation; reference to relevant US FDA regulations (e.g. 21 CFR 177.2600 for elastomers, 177.1550 for PTFE) and/or NSF 51 listed materials
- Migration/extraction: testing with food simulants (aqueous, acidic, fatty, alcoholic) at defined temperature/time
- Thermal/chemical resistance: cleaning and disinfection media (CIP/SIP), temperature cycling, steam
- Surface/design hygiene: smooth, low-porosity surfaces; avoidance of gaps, dead spaces and non-cleanable geometries
- Traceability and documentation: material certificates, test reports, declarations of conformity, batch tracking
Typical materials and standard references
| Material | Characteristics | Rule/standard reference | Notes |
|---|---|---|---|
| EPDM (white/black) | Very good against water/steam, CIP-resistant | NSF/ANSI 51; FDA 21 CFR 177.2600 | Less suitable for oily/fatty media |
| NBR (white) | Good against oils/fats | NSF/ANSI 51; FDA 21 CFR 177.2600 | Limited in hot steam; compound selection is important |
| FKM/FPM | Broad chemical/temperature resistance | NSF/ANSI 51; material-specific FDA references | Often the first choice for aggressive CIP media |
| Silicone (VMQ/LSR, platinum-cured) | Very temperature-resistant, neutral in taste | NSF/ANSI 51; FDA 21 CFR 177.2600 | Platinum curing preferred; avoid peroxide residues |
| PTFE / ePTFE | Universally chemically resistant, very pure | NSF/ANSI 51; FDA 21 CFR 177.1550 | ePTFE for rough flanges/low bolt loads |
| TPE/TPU | Elastic, easy to process | NSF/ANSI 51 (material-dependent) | Check compound-specific approvals |
We also serve EU regulations (e.g. Regulation (EC) No 1935/2004; EU 10/2011 for plastics).
How do products achieve NSF conformity?
- Material screening: comparison of the formulation with approved/customary food-grade qualities
- Design check: food zone classification, minimum thicknesses, surface quality, CIP/SIP suitability
- Test strategy: migration/extraction including temperature profile; sensory/resistance tests if required
- Documentation: test reports, declaration of conformity (CoC/DoC), batch traceability
- Series maintenance: monitor formulation/colour changes, supplier changes and process changes
Benefits of NSF conformity
| Benefit | End customers | Manufacturers/OEMs |
|---|---|---|
| Safety | Neutral taste/odour, low transfer | Minimised liability and risk |
| Market access | Clear food-grade signal | Compliance with specifications/audits |
| Efficiency | Compatibility with CIP/SIP | Fewer complaints, stable processes |
Frequently asked questions about NSF conformity
Is NSF/ANSI 51 the same as FDA compliant? No. NSF/ANSI 51 often references FDA sections, but requires its own assessment according to the standard (including zones and migration/extraction). The two proofs complement each other.
Do approvals apply to every colour/hardness? Not automatically. Pigments/plasticisers can change the assessment, so every relevant change must be retested.
Difference from NSF/ANSI 61? NSF/ANSI 61 concerns drinking water system components. For food equipment, NSF/ANSI 51 is the relevant standard.
Standards & approvals
Further standards
Cooperation
Seals according to NSF?
Tell us the application, medium and required standard. We will recommend the right material and the appropriate approval.