{"id":1691,"date":"2026-11-12T20:23:00","date_gmt":"2026-11-12T12:23:00","guid":{"rendered":"https:\/\/www.bosssealing.com\/?p=1691"},"modified":"2026-11-10T12:00:25","modified_gmt":"2026-11-10T04:00:25","slug":"food-grade-seal-materials","status":"publish","type":"post","link":"https:\/\/www.bosssealing.com\/pt\/food-grade-seal-materials\/","title":{"rendered":"Os 7 melhores materiais de veda\u00e7\u00e3o de qualidade alimentar: FDA 21 CFR 177.2600 e UE 10\/2011 explicados"},"content":{"rendered":"

“Food grade” is the most loosely used phrase in seal purchasing. It appears on quotations, in catalog descriptions and on invoices, and it carries no legal definition on its own. What it means in practice is that a specific compound, in a specific finished form, satisfies a specific regulation for a specific food type \u2014 and the differences between those three specifics are where recalls come from.<\/p>\n

This guide covers what the two main regulatory systems actually require, then ranks seven materials by where they genuinely fit rather than by reputation.<\/p>\n

\"White
Platinum-cured silicone and peroxide-cured EPDM seals for sanitary service, both white, both food-contact grades, not interchangeable.<\/figcaption><\/figure>\n

What the Law Actually Requires<\/h2>\n

United States: 21 CFR 177.2600<\/h3>\n

Rubber articles for repeated food contact fall under 21 CFR 177.2600. The regulation works in two layers. First, the compound may contain only the polymers and additives listed in the section \u2014 nitrile, EPDM, HNBR, silicone, FKM and others \u2014 and no substance beyond what good manufacturing practice requires. Second, the finished article has to pass an extraction test matched to the food type.<\/p>\n\n\n\n\n\n\n\n
Table 1 \u2014 21 CFR 177.2600 extraction limits, finished article<\/caption>\n
Food type<\/th>\nSimulant<\/th>\nConditions<\/th>\nLimit, first 7 h<\/th>\nLimit, next 2 h<\/th>\n<\/tr>\n<\/thead>\n
Aqueous<\/td>\nDistilled water<\/td>\nReflux, 9 h total<\/td>\n20 mg\/in\u00b2<\/td>\n1 mg\/in\u00b2<\/td>\n<\/tr>\n
Fatty<\/td>\nn-Hexane<\/td>\nReflux, 9 h total<\/td>\n175 mg\/in\u00b2<\/td>\n4 mg\/in\u00b2<\/td>\n<\/tr>\n
Dry food<\/td>\nNone required<\/td>\nGMP only<\/td>\n\u2014<\/td>\n\u2014<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Three consequences follow, and buyers miss all three. A compound that passed in water has not been tested for fatty food, and the fatty limit is nearly nine times the aqueous limit for a reason. Dry-food service requires no extraction test at all, so a “food grade” claim for a dry application may rest on GMP alone. And 177.2600 covers only the rubber \u2014 metal inserts, PTFE faces and plastic cages are assessed substance by substance under 21 CFR 174-179, most of them under 177.1550 for PTFE.<\/p>\n

Europe: 1935\/2004, GMP, and a gap worth knowing<\/h3>\n

Regulation (EC) 1935\/2004 sets the general rule: a material may not transfer constituents to food in quantities that endanger health or change the food’s composition, taste or smell. Regulation (EC) 2023\/2006 requires documented GMP at every stage.<\/p>\n

What surprises North American buyers is that the EU has no specific harmonized measure for rubber. Regulation (EU) 10\/2011 \u2014 the one most often quoted on seal certificates \u2014 covers plastics, including PTFE, and states explicitly that it does not apply to rubber or silicones. A declaration of compliance that cites 10\/2011 for an EPDM O-ring is citing a regulation that does not cover the part.<\/p>\n

For plastics under 10\/2011, the overall migration limit is 10 mg\/dm\u00b2 of food-contact surface, with individual specific migration limits for listed substances, and a written declaration of compliance is mandatory. For rubber, the practical route in Europe runs through national provisions \u2014 Germany’s LFGB with BfR Recommendation XXI is the most widely referenced \u2014 plus customer-specific specifications.<\/p>\n

Hygienic design: 3-A and EHEDG<\/h3>\n

Material compliance and cleanability are separate questions. A compound can be fully compliant and still create a bacteria trap in a groove. 3-A 18-03 sets rubber classes by maximum exposure temperature: Class I at 149 \u00b0C, Class II at 121 \u00b0C, Class III at 49 \u00b0C for product contact only, Class IV at 38 \u00b0C for product contact only. All four are tested against cleaning and sanitizing solutions up to 82 \u00b0C. EHEDG’s mechanical seal guideline covers arrangement and design rules that 3-A does not.<\/p>\n

The Seven Materials, Ranked by Fit<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Table 2 \u2014 Food-contact seal materials compared<\/caption>\n
Material<\/th>\nService range<\/th>\nDureza<\/th>\nHot water \/ CIP<\/th>\nFat and oil<\/th>\nRelative compound cost<\/th>\nWhere it wins<\/th>\n<\/tr>\n<\/thead>\n
Platinum-cured silicone (VMQ)<\/td>\n\u221260 to +200 \u00b0C<\/td>\n40-80 Shore A<\/td>\nFair below 130 \u00b0C<\/td>\nFraco<\/td>\n1.2-1.8\u00d7<\/td>\nDry heat, closures, sight-glass seals<\/td>\n<\/tr>\n
Peroxide-cured EPDM<\/td>\n\u221250 to +150 \u00b0C<\/td>\n50-90 Shore A<\/td>\nExcelente<\/td>\nFraco<\/td>\n1.0\u00d7<\/td>\nCIP circuits, steam, dairy and brewery<\/td>\n<\/tr>\n
FKM (food grade)<\/td>\n\u221220 a +200 \u00b0C<\/td>\n60-90 Shore A<\/td>\nFraco<\/td>\nExcelente<\/td>\n3-5\u00d7<\/td>\nFatty foods, frying oil, oily sauces<\/td>\n<\/tr>\n
FFKM<\/td>\n\u221220 to +300 \u00b0C<\/td>\n70-90 Shore A<\/td>\nBom<\/td>\nExcelente<\/td>\n15-25\u00d7<\/td>\nAggressive CIP chemicals, solvent-laden product<\/td>\n<\/tr>\n
NBR (food grade)<\/td>\n\u221230 a +100 \u00b0C<\/td>\n50-90 Shore A<\/td>\nFair<\/td>\nBom<\/td>\n0.6-0.8\u00d7<\/td>\nAmbient oily product, dry goods, water lines<\/td>\n<\/tr>\n
PTFE virgem<\/td>\n\u2212200 a +260 \u00b0C<\/td>\nNon-elastomeric<\/td>\nExcelente<\/td>\nExcelente<\/td>\n1.5-3\u00d7<\/td>\nGaskets, valve seats, chemical resistance<\/td>\n<\/tr>\n
UHMWPE<\/td>\n\u221280 to +80 \u00b0C<\/td>\nNon-elastomeric<\/td>\nGood below 80 \u00b0C<\/td>\nExcelente<\/td>\n0.8-1.2\u00d7<\/td>\nWear strips, guide rails, scraper edges<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

1. Platinum-cured silicone (VMQ)<\/h3>\n

The default for anything that touches dry food, and the one material most often chosen for the wrong reason. Silicone handles \u221260 to +200 \u00b0C continuously, stays flexible at freezer temperatures, and is odorless and tasteless, which is why it dominates baking equipment, closures and dispensing heads. Platinum-cure matters: peroxide-cured silicone leaves volatile byproducts that require a post-cure bake, and an under-post-cured part can taint product for weeks.<\/p>\n

What silicone does not do is fat. It swells in frying oil and in fatty dairy, and its tear strength is the lowest of the group, so it is a poor choice for any seal that gets pried out with a screwdriver during cleaning. Specify 60-70 Shore A and plan on replacing it, not on it surviving a knife.<\/p>\n

2. Peroxide-cured EPDM<\/h3>\n

The workhorse of wet food processing. EPDM resists hot water, steam, caustic CIP solutions and hypochlorite better than any elastomer at its price, and peroxide curing keeps compression set low enough to hold a sanitary clamp joint through repeated CIP cycles. Dairy, brewery, beverage filling and CIP pump seals are EPDM work.<\/p>\n

Two limits: it swells badly in mineral oil and moderately in animal fat, and it is attacked by aromatic and chlorinated solvents. A line that runs both a fatty product and a caustic clean cannot be sealed with one compound, and pretending otherwise produces the classic failure of a swollen, nibbled gasket after six weeks.<\/p>\n

3. FKM, food grade<\/h3>\n

Fat and temperature together is where FKM earns three to five times the compound cost. A food-grade FKM handles continuous 200 \u00b0C, resists animal and vegetable fats, and holds up against the acidic and oily products that destroy EPDM. Fryer applications, oily sauce lines, chocolate and confectionery equipment with hot oil all belong here.<\/p>\n

FKM is the wrong answer for steam and hot water \u2014 it degrades in steam above roughly 150 \u00b0C and in hot water generally, which is exactly the environment many food plants clean with. Check whether the part sees steam before selecting on product compatibility alone.<\/p>\n

4. FFKM<\/h3>\n

Perfluoroelastomer is what you buy when the CIP chemistry includes solvents, strong oxidizers or amines that break FKM, and when the temperature sits above 200 \u00b0C. It behaves like PTFE with elastic recovery. It also costs 15-25 times an EPDM compound, has lower tensile strength, and is usually a special order.<\/p>\n

The honest use case: a valve or pump in a pharmaceutical or specialty chemical food line where a seal change means a validated shutdown. Everywhere else, the money is better spent on a correct gland.<\/p>\n

5. Food-grade NBR<\/h3>\n

Cheap, oil-resistant, and adequate for ambient fatty product and for water lines that never see CIP. Food-grade NBR uses non-staining antioxidants and no nitrosamine-generating accelerators, which is the only thing that separates it from a general-purpose nitrile. Above 100 \u00b0C, or in repeated caustic cleaning, it hardens and takes set faster than EPDM, and the difference is not visible until the joint weeps.<\/p>\n

6. Virgin PTFE<\/h3>\n

Not an elastomer, and should not be specified as one. PTFE gaskets and valve seats cover the widest chemical range and the widest temperature range of anything on this list, \u2212200 to +260 \u00b0C, and they do not extract into food. They also cold-flow under load, which means a PTFE gasket in a clamp joint relaxes and needs re-torquing, and a PTFE seal in a dynamic application wears quickly unless it is filled.<\/p>\n

Use virgin PTFE where chemical inertness is the requirement and the joint is bolted. Use filled PTFE or a spring-energized PTFE jacket where the seal has to move. Under 10\/2011, PTFE parts need a declaration of compliance with migration data, not a 177.2600 letter.<\/p>\n

7. UHMWPE<\/h3>\n

The material for wear parts rather than seals: guide rails, star wheel inserts, scraper edges, conveyor wear strips. It is FDA-compliant in the right grade, has the lowest friction of any unfilled polymer at its price, and resists abrasion better than PTFE. Its limits are temperature \u2014 80 \u00b0C continuous \u2014 and creep under sustained load. In a plant that steam-cleans at 90 \u00b0C, a UHMWPE guide will deform and the line will track badly within a month.<\/p>\n

Three Documents, and What Each One Proves<\/h2>\n\n\n\n\n\n\n\n\n
Table 3 \u2014 Compliance documents for a food-contact seal<\/caption>\n
Document<\/th>\nIssued by<\/th>\nWhat it covers<\/th>\nWhat it does not cover<\/th>\n<\/tr>\n<\/thead>\n
FDA letter of guaranty<\/td>\nThe manufacturer<\/td>\nCompound acceptable under 177.2600 for a named food type<\/td>\nFDA does not certify seals; the letter is the supplier’s own statement<\/td>\n<\/tr>\n
EU declaration of compliance<\/td>\nMaterial or part supplier<\/td>\n1935\/2004 plus, for plastics, 10\/2011 with migration data<\/td>\nRubber and silicone, which 10\/2011 excludes<\/td>\n<\/tr>\n
3-A 18-03 certificate<\/td>\nRubber manufacturer, backed by lab test<\/td>\nCompound, rubber class, part number<\/td>\nDesign hygiene, which is assessed separately<\/td>\n<\/tr>\n
Migration test report<\/td>\nAccredited laboratory<\/td>\nActual extraction results for named simulants and conditions<\/td>\nAny food type or temperature not tested<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Ask for the document that names the compound, not the material family. A 177.2600 letter for “silicone” is worth nothing; a letter naming the compound number, its durometer and the food type is the one an auditor will accept. Compound numbers change when formulation changes, so check that the number on the certificate matches the parts in the box \u2014 this is the single most common finding in a supplier audit.<\/p>\n

Where These Programs Fail<\/h2>\n

Five failure points account for most non-conformances we see:<\/p>\n