Materials & Process9 min read

    Food-Grade vs Medical-Grade Silicone: FDA, LFGB and What Buyers Must Specify

    The real difference between food-grade and medical-grade silicone, what FDA 21 CFR 177.2600 and LFGB actually test, when you need platinum cure and post-curing, and how to write it into your specification.

    Key takeaways

    • "Food-grade" is a compliance claim backed by test reports, not a material type — always ask which standard, which test lab and which batch.
    • FDA 21 CFR 177.2600 covers rubber articles for repeated food contact; LFGB (Germany) is generally the stricter test, including sensory and volatile matter limits.
    • Medical-grade silicone adds biocompatibility testing (ISO 10993 / USP Class VI) and stricter traceability — it is a documentation regime, not just a compound.
    • Platinum-cured silicone plus proper post-curing is the practical baseline for food-contact and infant products.
    • Specify grade, cure system, post-cure schedule, certificate scope and batch traceability in your purchase order, not in an email.

    "Food-grade silicone" appears on nearly every supplier's website, and it means almost nothing on its own. What protects your product — and your importer — is a specific standard, a specific test report and a specific batch. Here is how the certifications actually work and what to write into your specification.

    Quick answer

    Food-grade means the finished article passes a food-contact standard such as FDA 21 CFR 177.2600 or German LFGB. Medical-grade means the material additionally passes biocompatibility testing (ISO 10993 or USP Class VI) under strict traceability. If your product touches food, specify LFGB when selling into Europe and FDA when selling into the US; if it enters the body or contacts broken skin, you need medical-grade with documented lot control.

    1. What each standard actually tests

    StandardRegionWhat it evaluates
    FDA 21 CFR 177.2600United StatesPermitted ingredients and extractable limits for rubber articles in repeated food contact
    LFGB § 30/31 (BfR XV)Germany / EUVolatile matter, extractables, and a sensory test for odour and taste transfer
    EU 1935/2004 + 10/2011EUGeneral food-contact framework and migration limits
    ISO 10993 / USP Class VIGlobalCytotoxicity, sensitisation, irritation and implantation biocompatibility
    ISO 9001:2015GlobalQuality management system — process control, not material safety

    2. Cure system matters more than most buyers realise

    Peroxide-cured silicone leaves organic by-products that must be removed by post-curing; it can also carry a faint odour and slight colour shift. Platinum-cured silicone cures by addition with essentially no by-products, giving clearer material, lower volatiles and better taste and odour performance. For teethers, nipples, kitchenware and medical parts, platinum cure is the practical default.

    Platinum systems are, however, sensitive to cure inhibition from sulfur, amines, tin catalysts and some plasticisers — one reason mixed tooling and mixed-material workshops need discipline.

    3. Post-curing is where compliance is won or lost

    A post-cure of about 200 °C for 2–4 hours in a circulating oven drives off residual volatiles, stabilises compression set and eliminates the "silicone smell" that fails LFGB sensory testing. It costs oven time and it is often the first thing a low bidder quietly removes from the process. Specify it explicitly and ask for the oven record.

    4. What to write into your specification

    • Material grade and supplier compound reference.
    • Cure system: platinum or peroxide.
    • Post-cure schedule: temperature and duration.
    • Applicable standards and required test reports with issue date.
    • Colourant compliance — pigments must be food-contact approved too.
    • Batch traceability: raw material lot recorded against production lot.
    • Re-test interval — many buyers require annual re-testing.

    5. Common compliance mistakes

    1. Accepting a certificate for a different compound than the one being molded.
    2. Certifying the silicone but ignoring the pigment or the printed logo ink.
    3. Assuming FDA compliance satisfies EU customers — it does not cover LFGB sensory testing.
    4. Approving a sample that was post-cured, then buying production that was not.
    5. No traceability, so a single complaint forces a full recall instead of a lot recall.

    Related reading: manufacturing silicone baby teethers and choosing your molding process.

    Working with Tongsheng

    Dongguan Tongsheng Electronic Technology Co., Ltd. has manufactured silicone rubber molds and silicone products since 2014. We run in-house CNC tooling, compression and liquid silicone injection molding, and a testing lab, from a 2,000+ sqm ISO 9001:2015 certified factory in Humen Town, Dongguan, with 100+ staff and 15 engineers. Food-grade (FDA / LFGB), medical-grade and industrial-grade compounds, Shore A 10–80, Pantone and RAL color matching.

    Send 2D/3D drawings (STP, IGS, PDF) and we quote within 24 hours — request a quote, email coraycn@gmail.com, or message us on WhatsApp.

    Frequently asked questions

    What is the difference between food-grade and medical-grade silicone?
    Food-grade silicone is certified safe for food contact under standards such as FDA 21 CFR 177.2600 or LFGB. Medical-grade silicone additionally passes biocompatibility testing such as ISO 10993 or USP Class VI and carries stricter batch traceability and process control. All medical-grade material is suitable for food contact; not all food-grade material qualifies as medical-grade.
    Is LFGB stricter than FDA for silicone?
    In practice yes. LFGB testing to the German standard includes volatile matter limits and a sensory (odour and taste) evaluation, which many FDA-compliant compounds do not pass without a full post-cure. Buyers selling into the EU should specify LFGB explicitly.
    Do silicone products need post-curing?
    For food-contact and infant products, yes. A post-cure of roughly 200 °C for 2–4 hours drives off residual volatiles, removes odour and stabilises physical properties. Skipping it is the most common cause of failed LFGB sensory tests.
    How do I verify a supplier's food-grade claim?
    Ask for the test report itself — issued by an accredited lab such as SGS, Intertek or TUV — and check the report date, the tested material, the applied standard and the entity named on it. A generic certificate with no material identification is not evidence.

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