Silicone is a material of choice for countless applications in the medical, infant care, food service, and cosmetic industries. It’s inherently resistant to microbial growth, but as a brand owner, when you’re offering products in such sensitive applications, the absolute safety—or “sterility”—of your product carries the weight.
This guide will walk you through the regulatory requirements for silicone items, the core technologies available to achieve them, and how to ensure your products meet the highest standards of safety.
When and Why Silicone Needs Sterilization?
Sterilization is the process of destroying or eliminating all forms of microbial life, including fungi, bacteria, viruses, and spores. Silicone products come in contact with a host of these microbes during manufacturing, packaging, and handling. So, sterilization is essential, particularly for products intended for medical or infant care.
Even outside these applications, silicone used in kitchens or food processing, or beauty products must meet strict hygiene standards to ensure no viable pathogens remain before use.
The main advantages of sterilizing silicon are:
1.Consumer Safety: It prevents infections and cross-contamination, especially vital for products that penetrate the skin or mucosal membranes (medical devices) or are ingested (baby pacifiers, spoons, etc).
2.Regulatory Compliance: Many regulatory bodies, such as the FDA (Food and Drug Administration) in the U.S. and the EFSA (European Food Safety Authority) in Europe, mandate specific sterilization or sanitization standards for various product categories (silicon or not). Non-compliance can lead to recalls and legal issues.
3.Maintaining Quality: While less common, certain microbial contaminants could potentially affect the long-term performance or appearance of the silicone material itself. Regular sterilization (or at least sanitizing) prevents stains, odors, and wear from residues, keeping silicone looking and performing like new longer.
Sterilization Needs for Different Silicone Materials
Silicones are categorized by their manufacturing process, and the approach to sterilization must match their form:
Solid Silicone (High Consistency Rubber (HCR))
It’s a high-viscosity, putty-like material cured under high pressure and temperature to manufacture products like bowls, bakeware, teether toys, etc. It can usually withstand heat and steam, so boiling (at 100 °C) or autoclaving (steam at 121–134 °C) is effective without damaging the material. (You’ll learn more about these methods in the next section.)
Liquid/Uncured Silicone (Liquid Silicone Rubber (LSR), Oils)
This is a low-viscosity, pumpable material typically injection-molded into complex shapes like baby bottle nipples, diving masks, and soft-touch wearables.
1.LSR parts have excellent mechanical properties. However, their use in highly sensitive products often requires gentler methods like filtration (for oils) or irradiation if in the final form, to avoid material degradation over time.
2.In some cases (e.g., medical-grade silicone fluid), ethylene oxide (EtO) gas is preferred because it penetrates porous/packaged fluids at low temperature.
Silicone Gels and Gaskets
These usually follow solid-silicone procedures, but if any part traps moisture or contains fillers, dry heat or special chemical sterilants may be chosen.
Methods of Sterilizing Silicone: Principles, Applications, Pros & Cons
Below are 6 common sterilization methods applicable to silicone, balancing efficacy with material compatibility.
|
Sterilization Method |
Principle |
Applicability to Silicone |
Pros |
Cons |
|
Steam (Autoclave) |
Uses saturated steam (typically 121 °C at 15 psi for 15–20 minutes, or flash cycles at 134 °C for 3–5 minutes).
Penetrates microbes to denature and coagulate their protein structure. |
Excellent for heat-stable, non-porous solid and liquid silicones
-Widely used in labs and hospitals. -Baby bottle sets at home
|
-Fast -Non-toxic -No-residue -Cost-effective |
-Requires a pressure vessel -May cause a slight expansion of silicone -Possible yellowing or stickiness after many cycles -Not suitable for products that trap air/steam |
|
Dry Heat |
Hot air at ~160–180 °C for extended periods kills microorganisms (baked sterilization) |
Silicone’s heat tolerance makes this possible for simple parts (like O-rings) |
-No moisture -No residue -Non-toxic |
-Very long cycle -Not suitable for heat-sensitive or multi-material items |
|
Ethylene Oxide (EtO) Gas |
A gaseous alkylating agent that sterilizes at low temperatures (≈37–63 °C) by diffusing into microorganisms.
|
Ideal for heat-sensitive or complex silicone items (for example, masks or tubing with electronics) |
-Effective at low temperatures -Compatible with delicate or multi-material assemblies.
|
-Long cycle time -Can leave toxic residues ( requires up to 24 hrs off-gassing) -Potentially carcinogenic; strict environmental controls needed |
|
Gamma Irradiation |
Uses high-energy photons from Cobalt-60 to break microbial DNA bonds. It is a cold process.
|
Excellent for single-use, pre-packaged medical devices.
|
-Excellent penetration (even into sealed products) -No heat or moisture. -No residue -Precise, validated dose |
-May alter silicone properties (increased hardness, reduced elasticity) -Generally not accessible outside industrial facilities |
|
Vaporized Hydrogen Peroxide (VHP) / Plasma |
Ionized H₂O₂ vapor at low temperature generates free radicals that rapidly destroy pathogens. |
Suitable for moisture/heat-sensitive devices (e.g., integrated electronics). |
-Fast cycle time -Low temperature -No toxic residues -Eco-friendly |
-Expensive equipment -Typically only for small batches or delicate tools -Best for surface sterilization |
|
UV-C or Electron Beam Irradiation |
Uses high-energy electrons or UV-C light (254 nm) with similar effects to gamma radiation but shorter penetration depth.
|
Suitable for low-density, thin-walled silicone products |
-Even faster than gamma -No radioactive source or chemical
|
-Only kills surface microbes -Ineffective in shaded or obstructed areas -Potential surface effects at high doses |
Regulatory Standards for Food-Grade Silicone
For products that come into contact with food, beverages, or the mouth (e.g., kitchen spatulas, baking molds, baby pacifiers), the primary concern is the chemical safety of the silicone itself, followed by microbiological purity.
Although there is no “sterilization standard” per se for silicone specifically, safety regulations ensure it can withstand the required cleaning without leaching toxins. Key standards include:
1.FDA CFR 21 §177.2600 (USA): Specifies FDA-approved formulations for food-contact rubber. Compliant items must not contain harmful additives and must pass extractables limits. This ensures that silicone remains inert during cooking or sterilizing (up to ~230 °C).
2.EU (LFGB/1935/2004): EU regulations for materials in contact with food (Regulation 1935/2004) and German LFGB approvals test for overall and specific migration into food simulants. Many “food-grade silicone” products in EU markets carry LFGB certification.
3.China GB 4806.11 (GB4806-2016): The Chinese national standard for rubber (including silicone) food-contact materials. It outlines limits on harmful substances and requires tests for specific migration.
4.Hygienic Processing Standards (Food Industry): NSF/ANSI standards (like NSF 51 for food equipment) require materials to be easily cleanable. While not specific to silicone, silicone used in food equipment must be smooth, inert, and able to withstand cleaning chemicals (e.g., bleach, hydrogen peroxide).
5.USP Class VI / ISO 10993: These are medical biocompatibility standards, not required for consumer food use, but mentioning them signals a high level of safety.
Silicon Before and After-Use Cleaning and Sterilization
For reusable silicone items—particularly in the food, baby, and home sectors—the user's role in maintenance is crucial for minimizing microbial load and ensuring the material’s longevity.
The First Use ProtocolNew silicone items often carry manufacturing residues. CDC strongly recommends sterilizing them once before giving them to consumers or babies.
1.Wash the item with warm water and a mild dish soap using a soft cloth or non-abrasive sponge.
2.It is also highly recommended to submerge the item completely in a pot of rolling boiling water.
Boil for 3 to 5 minutes (confirm with the product's instruction manual).
Or use a baby steam-sterilizing unit per manufacturer’s instructions.
Periodic SterilizationFor baby products and food contact items, additional sterilization cycles can kill any lingering germs.
Sterilize baby bottles daily.
For general users, sanitizing weekly or monthly is a good practice.
You can re-boil or run them through a steam sterilizer (10 minutes typically) or run them through dishwashers with a sanitize cycle.
Daily Care Recommendations for Silicone Products
Routine, effective cleaning is the best defense against grime, odor, and microbial buildup.
Wash items after each use with mild dish soap and warm water or use the dishwasher, as most food-grade silicone products are dishwasher-safe. Place items on the top rack (to keep them away from heating coils) and run on a hot wash plus heated drying cycle.
Do not use bleach, ammonia, or undiluted alcohol on silicone at home. These can degrade the silicone over time. Instead,
If silicone items become stained (e.g., from tomato sauce), create a paste of baking soda and water, apply it to the stain, let it sit for 20 minutes, then gently scrub with a soft brush.
For eliminating odors, soak the product for 30 minutes in a diluted vinegar solution (1:3 vinegar to water).
Commercial silicone cleaners exist, but are rarely needed for home use.
Store items in a clean, dry place (sealed container or clean shelf). Avoid storing while still damp, which could encourage mold.
If a silicone item begins to show cracks, splits, or permanent disintegration, replace it (especially for baby gear).
KEAN's Sterilization Solutions and Assurance
At KEAN Silicone, we understand that sterility is not an option—it’s a commitment. As a trusted OEM/ODM partner to global brands in the infant care, and food contact sectors, we integrate advanced sterilization capabilities and rigorous quality control into every stage of production. From material selection to final packaging, your products are engineered to meet the highest standards of safety and performance.
Advanced Sterilization Processes & Equipment
There are four common sterilization processes, and at KEAN, we tailor our approach based on the specific material, design, and application requirements of your silicone products.
Ethylene Oxide (EtO) Sterilization: Ideal for heat-sensitive and complex multi-material assemblies, our controlled EtO systems ensure deep penetration and microbial eradication, followed by strict aeration to eliminate residual gas.
Gamma Irradiation: For single-use medical and pre-packaged products, we utilize gamma irradiation—a cold-process method that delivers excellent microbial elimination without compromising structural integrity.
Autoclave (Steam) Sterilization: Suitable for heat-stable solid silicone items, our automated autoclaving systems provide fast, non-toxic, and residue-free sterilization—ideal for reusable consumer and medical goods.
VHP & UV-C Technologies: For moisture-sensitive or electronics-integrated components, we offer vaporized hydrogen peroxide and targeted UV-C treatments—delivering rapid, eco-friendly surface sterilization without toxic residues.
Each process is supported by fully validated protocols, automated handling systems, and in-process monitoring to ensure consistent, repeatable results—batch after batch
Quality & Compliance Assurance
KEAN works in alignment with international regulatory frameworks—including FDA CFR 21, EU LFGB, and China GB 4806.11—and holds relevant certifications such as ISO 13485 for medical devices and ISO 9001 for quality management. Our in-house lab conducts extractables, migration, and biocompatibility testing where required, so you can be confident your products are safe, compliant, and ready for global market
Partner with KEAN for Sterilization-Ready Silicone SolutionWhen you choose KEAN, you’re not just sourcing silicone products—you’re investing in safety, reliability, and end-to-end accountability. Let us help you build trusted products that protect your customers and strengthen your brand.
Contact KEAN today to discuss your sterilization and sourcing needs.