What You Need To Know
Seals play a vital role in today's industrial and sanitary applications—from keeping fluids contained to protecting systems from contaminants. The requirements are ever-expanding. As equipment becomes more specialized and regulations more stringent, selecting the right sealing material has never been more critical. One of the most important regulations in food and beverage processing is FDA 21 CFR 177.2600, which governs rubber materials intended for repeat use in contact with food.
What Is FDA 21 CFR 177.2600?
FDA 21 CFR 177.2600 specifies the criteria for rubber compounds used in food applications. It applies to natural and synthetic polymers intended for repeated use in holding, manufacturing, packaging, packing, preparing, processing, producing, transporting, and treating food. The regulation outlines approved elastomers and additives—including vulcanizing agents, accelerators, retarders, activators, antioxidants, antiozonants, plasticizers, fillers, colorants, lubricants, emulsifiers, and anything else deemed miscellaneous — along with maximum allowable concentrations.
In addition to compositional requirements, the regulation mandates that rubber materials be manufactured under Good Manufacturing Practices (GMP) and thoroughly cleaned before their first use in food-contact applications.
Extraction Requirements for Food Contact
Depending on the type of food the rubber will contact, different extraction tests must be met:
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For Aqueous Foods:
“The food-contact surface of the rubber article in the finished form in which it is to contact food when extracted with distilled water at reflux temperature shall yield total extractives not to exceed 20 milligrams per square inch during the first 7 hours of extraction, nor to exceed 1 milligram per square inch during the succeeding 2 hours of extraction.”
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For Fatty Foods:
“The food-contact surface of the rubber article in the finished form in which it is to contact food when extracted with n-hexane at reflux temperature shall yield total extractives not to exceed 175 milligrams per square inch during the first 7 hours of extraction, nor to exceed 4 milligrams per square inch during the succeeding 2 hours of extraction.”
These requirements ensure that rubber seals will not leach harmful substances into food products during processing or packaging.
Beyond Compliance: Application-Specific Material Selection
While FDA compliance is a necessary starting point, choosing a material based on your application's conditions is equally important. For example:
- NBR (Nitrile Rubber) is a strong candidate for applications involving oily or fatty substances due to its excellent oil resistance.
- Silicone performs well in environments with high or fluctuating temperatures, making it ideal for thermal processing lines
Don’t Overlook Seal Profile Selection
Material selection is only half the equation. The seal profile — a simple o-ring, sanitary gasket, or complex radial shaft seal—must also match the application's mechanical and chemical demands.
Profile geometry can impact:
- Compression
- Sealing effectiveness
- Long-term durability
Final Thoughts
Choosing the right FDA-compliant rubber seal means considering both regulatory requirements and application-specific factors. With a wide range of elastomers and seal designs available, a solution that delivers both compliance and performance is possible.
For detailed information on material formulations or testing requirements, consult FDA 21 CFR 177.2600.