Silicone products require being sterilized properly before use. For the silicone industry, boiling silicone to sterilize is regarded as the most efficient and cost-effective compliant method. However, the boiling time to sterilize silicone is not consistent. Hence, we write this guide to offer you an authoritative answer.
Is It Safe to Boil Silicone?
Silicone has excellent temperature resistance and is very durable. It can withstand temperatures ranging from 200°C to 250°C (392 to 482°F). Within this temperature range, the silicone still maintains chemical stability and does not easily degrade. Usually, the boiling water temperature is 100°C (212°F), so the silicone remains safe when being boiled to sterilize.
What Type of Silicone Can Be Boiled Safely?
You need to be aware that not all grades of silicone are suitable for boiling sterilization. We suggest that you sterilize food-grade silicone and medical-grade silicone by boiling. However, industrial-grade silicone does not support boiling sterilization. The reasons are as follows:
Food-grade silicone and medical-grade silicone are non-toxic. They do not contain harmful substances such as heavy metals and plasticizers. Therefore, they will not precipitate toxins at high temperatures. Thus, you can safely use the sterilized silicone for the food or medical industries.
In addition, food-grade silicone has also passed strict FDA and LFGB certifications. And the medical-grade silicone also meets the ISO 10993, USP Class VI, and other biocompatibility standards. This further shows that food-grade silicone and medical-grade silicone are very safe.
However, industrial-grade silicone has more impurities. This kind of silicone contains heavy metals and recycled materials. When it’s at high temperatures, the harmful substances inside will precipitate quickly. Moreover, boiling sterilization will also accelerate the deformation and aging of the silicone. Therefore, we do not suggest you sterilize industrial silicone by boiling it.
How Long Should You Boil Silicone to Sterilize It?
Food-grade silicone and medical-grade silicone can both be sterilized by boiling, but there are still some differences between them.
What’s more, there are some items you need to know about sterilizing silicone in boiling water. For example, you must completely immerse the silicone. And don’t let them touch the wall and the bottom of the pot. Then, after the water reaches 100 ° C, you can start the timer.
After knowing these boiling tips, we will introduce the boiling time of food-grade silicone and medical-grade silicone for you.
Food-Grade Silicone Boiling Sterilization Time
Food-grade silicone products usually include silicone kitchen utensils, baby products, molds, and sealing rings. The following are the standard boiling times for these common food-grade silicone products. You can follow our instructions to sterilize silicone products safely.
Standard Food Grade Silicone
The standard food-grade silicone is the most widely used. It mainly includes general silicone accessories, sealing rings, and daily food contact products.
Due to connect with oil for a long time, before boiling silicone to sterilize, you need to thoroughly clean the oil stains on its surface.
- If you want to disinfect silicone daily, you can boil it for 5 minutes.
- If you need to sterilize the silicone deeply, you need to boil it for 8-10 minutes.
- Please do not keep the silicone boiling for more than 15 minutes, as prolonged high-temperature boiling will cause the silicone to deteriorate. This makes the silicone age and deform.
Platinum Cured Baby-Grade Silicone
Platinum vulcanized silicone is of high purity. So it’s widely used in baby products and delicate food contact products.
- If you only need routine disinfection, you can boil it in water for 3-5 minutes.
- If you want to deeply sterilize the silicone, please boil it for 10 minutes.
- Although platinum vulcanized silicone has excellent high-temperature resistance, don’t boil your silicone for more than 20 minutes at a time.
- In addition, if you need to repeatedly sterilize the silicone, we suggest you limit the single boiling silicone time to no more than 15 minutes. This way, the silicone hardly ages or deforms.
Thick-Walled Heavy-Duty Silicone
Thick-walled silicone mainly includes thickened kitchen utensils, large-sized solid silicone parts, and thick silicone sheets.
Due to its thick structure, heat penetrates the silicone slowly when boiling. So if you boil silicone for a short time, it cannot achieve good sterilization.
- To achieve thorough sterilization, we recommend that you boil it for 12-15 minutes.
- Meanwhile, be careful not to exceed 20 minutes at a time.
Medical-Grade Silicone Boiling Sterilization Time
We will also tell you how long you should boil medical-grade silicone to sterilize. Depending on the different types, we have listed the following three:
Basic Medical-Grade Platinum Silicone
Basic medical platinum vulcanized silicone mainly includes medical silicone tubes, respiratory accessories, and instrument sheaths.
If you want to sterilize these medical silicone products, you just need to boil them for 5-10 minutes.
This duration can kill common bacteria like E.coli and Salmonella without causing the silicone to age excessively. This complies with the routine sterilization requirements for USP Class VI external medical devices.
High-Purity Medical LSR Liquid Silicone
High-purity medical liquid silicone is often used to manufacture precision medical accessories and seals. It usually needs to undergo multiple sterilizations.
- For high-frequency regular sterilization, boiling silicone for 5-10 minutes is sufficient. This is because LSR has fast heat conduction. If you over-boil it, this will accelerate its aging.
- If you need to deeply sterilize medical liquid silicone, 10-15 minutes is also reasonable. This is suitable for precise medical accessories with many gaps. A typical example is the silicone one-way valve for infusion pumps.
Implant-Grade Medical Silicone
Implant-grade silicone is the most special medical-grade silicone. Due to the need to implant into the human body, sterilizing implant-grade silicone is demanding. To remove bacteria and process residues, you can boil it for 10-15 minutes. But this ordinary boiling can only clean the surface of silicone, but cannot make it sterile.
As a result, if you want to achieve implant-grade sterilization, you must combine high-pressure steam sterilization and ethylene oxide sterilization. These professional sterilization methods can kill heat-resistant pathogens such as spores. Thus, your sterilized silicone can meet the sterile requirements of ISO 10993.
Silicone Boiling Sterilization Time Chart
The following chart summarizes how long it takes to boil different types of silicone to sterilize.
To sum up, in most cases, silicone should be boiled for 5–10 minutes to effectively kill common bacteria, while thicker or medical-grade silicone may require up to 15 minutes.
| Silicone Material Classification | Daily Routine Disinfection Boiling Time | Deep / Full Sterilization Boiling Time | Single Maximum Boiling Limit | Key Remarks |
| Standard Food-Grade Silicone | 5 minutes | 8–10 minutes | ≤15 minutes | General seals & daily food-contact silicone |
| Platinum Cured Baby-Grade Silicone | 3–5 minutes | 10 minutes | ≤20 minutes Repeated use: ≤15 minutes | High purity for baby & precision food products |
| Thick-Walled Heavy-Duty Silicone | — | 12–15 minutes | ≤20 minutes | Slow heat penetration due to the thick structure |
| Basic Medical-Grade Platinum Silicone | 5–10 minutes | 5–10 minutes | — | USP Class VI, external medical accessories |
| High-Purity Medical LSR | 5–10 minutes | 10–15 minutes | — | Fast heat conduction, for precision repeated-use medical parts |
| Implant-Grade Medical Silicone | — | 10–15 minutes | — | Boiling only for surface cleaning; requires autoclave/EO sterilization for official implant-grade sterility (ISO 10993) |
Step-by-Step Guide to Sterilizing Silicone
If you don’t know how to sterilize silicone, read the following detailed steps. This allows you to ensure the sterilization effect without damaging the silicone. In addition, you can also include it in your product manual for your customers to refer to.
- First, you need to prepare a clean and corrosion-resistant stainless steel pot. Then, add clean water to it. We recommend you use distilled or filtered water to avoid residual water buildup.
- Before boiling silicone, you need to clean it first. You should use a mild detergent and a cloth to remove dust and oil stains from the surface of the silicone. Then, rinse it with clean water to avoid any detergent residue.
- Then, place the cleaned silicone products in the pot. You need to ensure all the silicone pieces are fully submerged in the water. At the same time, leave some space between the silicone products to avoid overcrowding. This will make them heat up more evenly.
- Then start heating. You can only start timing when the water is completely boiling. And you need to choose the suitable boiling time based on the silicone type. Besides, make sure the water remains boiling at all times. If the water level drops, you should add water in time.
- After completing the boiling disinfection, you should turn off the heat and use clean tongs to remove silicone. Please avoid direct contact with your hands as it may cause you to burn.
- You should place the sterilized silicone in a clean and well-ventilated area to dry naturally. Once the silicone is completely dry, you store them in a clean, airtight environment.
FAQ
Why Does Silicone Require Different Boiling Times for Sterilization?
Silicone requires different boiling times for many reasons. Specifically, factors such as the thickness, formula, and grade will affect silicone heat conduction and sterilization effectiveness. Therefore, you need to choose different boiling times according to the silicone types.
What Are Alternative Methods to Sterilize Silicone Besides Boiling?
Besides boiling, silicone can also be sterilized by steam sterilization, food-safe disinfectants, or UV sterilization. These sterilization methods are stringent. If you want to achieve a thorough sterilization, please consider these methods.
Can All Silicone Kitchen Products Be Safely Boiled?
Not all silicone kitchen products are suitable for boiling to sterilize. Only food-grade silicone products can withstand high-temperature sterilization safely. You need to strictly follow this rule. Or it may cause you some unnecessary issues.
What Is the Difference Between Sterilization and Disinfection for Silicone?
Sterilization can eliminate all microorganisms, which include bacteria and spores. While disinfection only reduces surface bacteria to a safe level and does not guarantee complete sterilization. So you need to figure them out and choose the right method for your silicone.
Final Thought
If you want to purchase bulk silicone products that can safely withstand boiling sterilization, don’t miss Legensilico. As a professional silicone supplier from China, we offer you high-quality food-grade silicone and medical-grade silicone. This can avoid unnecessary problems during silicone sterilization. So feel free to connect us!
