For medical device manufacturers or those searching for silicone component suppliers, the safety of medical-grade silicone is important. This article will help you to learn more about medical-grade silicone and provide advice on selecting safe medical-grade silicone.
What Is Medical-grade Silicone?
Medical-grade silicone is a type of high-purity silicone material that has passed medical-grade safety standard certifications such as ISO 10993, and is specifically designed for use in the medical and healthcare fields. Its formulation, production process, and testing standards are far stricter than those of ordinary or food-grade silicone.
When you purchase, you may meet two types of medical-grade silicone: medical-grade liquid silicone rubber(LSR) and high-temperature vulcanized silicone rubber (HCR/HTV).
Is Medical Silicone Safe?
Medical-grade silicone that meets ISO 10993, USP Class VI, or other medical safety standards is safe. It is widely recognized and used as a material in medical catheters, patches, breathing masks, and even implants.
It can become unsafe if misused or if poor-quality medical-grade silicone is purchased. In short, safety is affected not only by the “medical-grade silicone” itself, but also by other factors.
Why is Medical-grade Silicone Safe for Use in Medical Devices?
Biocompatibility
The core reason why medical-grade silicone is widely used in the medical industry is its excellent biocompatibility.
For your product, this means that medical-grade silicone can safely come into contact with skin, mucosa, wounds, or other tissues. It is gentle and will not cause irritation to the human body. This is especially evident in products such as dressings or implants that come into contact with wounds, as it does not cause an excessive inflammatory response.
Hypoallergenicity
In addition to biocompatibility, medical-grade silicone is also hypoallergenic, which is especially important for products that require long-term contact or are intended for sensitive individuals.
You may have heard people say, “I’m allergic to silicone,” but in reality, silicone allergies are more often caused by fillers and additives present in the silicone. High-quality medical-grade silicone doesn’t contain these additives that easily cause allergic reactions.
True silicone allergies are very rare because medical-grade silicone itself doesn’t contain proteins that are easily recognized by the immune system and cause allergic reactions like latex.
Existing silicone allergy symptoms are often milder than type I immediate hypersensitivity reactions caused by latex, more often appearing as itching and small bumps on the skin. The allergic reaction will gradually subside when contact with the silicone product causing the allergy is stopped.
What’s more, ISO 10993 includes allergen testing. If the medical-grade silicone you are using has passed ISO 10993, you do not need to worry about silicone-related allergies.
Free from Harmful Substances
From the very beginning of its production, medical-grade silicone is subject to strict control. Medical-grade silicone is a high-purity material that doesn’t contain the many performance-enhancing additives found in industrially manufactured silicone rubber.
The fillers and additives that can be added to medical-grade silicone are also strictly limited. High-quality medical-grade silicone does not contain harmful substances such as BPA, PFAS, phthalates, or heavy metals during its production.
Medical-grade silicone typically uses a platinum curing system, which further enhances its safety. Compared to peroxide curing systems, which may produce and leave harmful residues, platinum curing systems not only do not produce toxic byproducts, but the catalysts used to promote the curing process themselves do not have harmful effects on the human body.
If you would like to learn more about the chemicals contained in medical-grade silicone, you can read What Is Silicone Made Of? How Compositions Affect Safety and Performance.
Stable Chemical Properties
Thanks to its stable silicon-oxygen molecular backbone, medical-grade silicone possesses highly stable chemical properties and is unlikely to react with drugs or human tissues.
Its chemical inertness and biocompatibility also prevent the adsorption of proteins or platelets onto its surface, thus avoiding thrombus formation or adhesion to wounds. This is why it can be used in wound dressings and implants, preventing secondary harm to patients.
It also has strong corrosion resistance, withstanding frequent washing with many cleaning agents. Even in prolonged contact with bodily fluids and most medications, it will not dissolve or release toxic chemicals, thus avoiding harmful effects on the human body or affecting drug purity.
This stability is maintained even after long-term use. Medical-grade silicone is highly durable and will not easily degrade or produce other substances that could compromise medical safety.
Wide Temperature Tolerance
A wide temperature adaptability is also a key feature of medical-grade silicone, allowing it to maintain stable performance in extremely low or high temperature environments.
Not only at body temperature, but also from -60℃ to 200℃, medical-grade silicone works normally without significant changes in its flexibility. This means that your product is less likely to deform, degrade in performance, or compromise safety even when subjected to temperature variations.
Suitable for Various Sterilization Methods
Hygiene is an important factor to consider when selecting materials for medical devices or pharmaceutical equipment, and medical-grade silicone’s compatibility with various sterilization methods makes it a wise choice.
Due to its excellent UV resistance, thermal stability, and chemical inertness, it can withstand most common sterilization methods used in medical or laboratory settings, including high-temperature steam, ethylene oxide, and gamma irradiation. Furthermore, even with prolonged use of these sterilization methods, they will not become brittle, crack, or yellow.
This simplifies sterilization and allows for greater flexibility in the design of medical devices. Recommended reading: How to Clean Medical-grade Silicone: The Ultimate Guide.
Clean Production Environment
A clean production environment is another guarantee of the hygiene of medical-grade silicone. To prevent high-quality medical-grade silicone products from being contaminated by bacteria or impurities in the production environment, they are often produced in cleanrooms.
The particle density in the air of these cleanrooms is strictly controlled, and corresponding levels are established based on different particle densities.
The materials used in the equipment for producing medical-grade silicone are also significantly different from those used in ordinary silicone production lines. High-quality stainless steel and smooth surfaces treated with processes such as electropolishing reduce the possibility of metal ions being released into the silicone raw materials.
From mixing to final molding and post-processing, every step of the medical-grade silicone production process is strictly controlled, ensuring that you receive a hygienic and highly clean product.
Strict Safety Standards and Testing
Strict safety regulations and testing are the ultimate safety guarantee for medical-grade silicone. Multiple regulatory agencies have implemented strict controls over the production and use of medical-grade silicone. For silicone to obtain formal medical-grade certification, it must pass a series of standards and tests, and its safety must be continuously monitored.
USP Class VI
The United States Pharmacopeia (USP) Class VI standard tests the safety of medical-grade silicone. It checks the purity of medical-grade silicone through systemic injection tests, intradermal injection tests, and implantation tests, ensuring its safety during short-term contact with the body.
ISO 10993
Once medical-grade silicone is manufactured into products, it must pass a series of tests outlined in ISO 10993. Depending on its application, medical-grade silicone products are classified into three categories: short-term contact, long-term contact, and implantation. Different categories of medical-grade silicone products require different tests.
If your product is a short-contact item such as silicone protective gloves or syringe stoppers, then only three basic tests are needed: cytotoxicity testing, irritation and sensitization testing, and systemic toxicity testing.
For products that come into long-term contact with the body, such as endotracheal tubes and drainage tubes, more detailed tests, such as genotoxicity testing, will provide a more reliable guarantee of safety. Products with the highest safety level, such as silicone implants, require further testing for carcinogenicity and reproductive toxicity.
FDA and MDR
Before being officially launched on the market, medical-grade silicone products may need to pass medical device regulatory certification. In the United States, this regulation is FDA 21 CFR issued by the U.S. Food and Drug Administration (FDA), while in Europe, it is the EU’s MDR 2017/745.
When Is Medical Silicone Not Safe?
Using Low-quality or Uncertified Silicone
While medical silicone itself is safe, using low-quality or uncertified silicone materials remains unsafe. Not all silicone is suitable for medical and healthcare applications. When selecting appropriate medical-grade silicone materials or products, you should ensure they have passed the corresponding safety tests and regulations.
If you choose materials with unclear safety properties, you may face problems obtaining other certifications later, and it could even lead to safety incidents, severely damaging your company’s reputation.
Large Quality Differences between Different Batches
Whether a supplier can guarantee the stable quality of products across different batches also affects the safety of medical-grade silicone. If the performance of the medical-grade silicone you purchase in bulk has a great change between different batches, your products may carry unforeseen medical risks.
Improper Use and Maintenance
Improper use or maintenance can also affect the safety of silicone. Medical-grade silicone has strict safety classifications, so it may become unsafe if products intended for short-term contact are subjected to long-term contact or other situations beyond their design purpose.
Even though medical-grade silicone has strong chemical stability, it can still be incompatible with some chemicals. Some lubricants or ointments may penetrate the silicone structure, causing it to swell and consequently leading to a decrease in performance and safety.
The medical field often has very high hygiene requirements for medical products. Even if medical-grade silicone itself is clean and can be thoroughly sterilized in various ways, it is still difficult to meet medical requirements without proper maintenance.
How to Choose Safe Medical-Grade Silicone?
Check Safety Certifications
When selecting medical-grade silicone, checking that it has passed the corresponding medical-grade safety standard certifications and tests is most important. These certifications are the most reliable safety guarantee compared to other forms of certification.
You should request relevant compliance certificates and test reports from suppliers, rather than relying solely on verbal statements or simple declarations to judge material quality. What’s more, you should not choose silicone products with uncertain descriptions, and they must be clearly labeled as “medical-grade silicone.”
Look, Smell, and Stretch
You can also make a basic assessment of the material’s safety by observing its appearance, smelling its odor, and performing simple physical tests.
High-quality medical-grade silicone typically has a uniform surface color and texture, no obvious impurities, and no pungent odor. If you stretch it by hand, it should not turn white and should return to its original shape well afterward. While these methods cannot replace professional testing, they can help in determining the quality of medical-grade silicone.
Confirm the Packaging
Standard medical-grade silicone products typically have clear batch information, sterilization markings, and complete packaging. Medical-grade silicone products, such as wound dressings and facial implants, are sterilized, so packaging is important for maintaining their hygiene. If the packaging is damaged or not airtight, the medical-grade silicone product inside may be polluted with bacteria.
Packaging also reflects the manufacturer’s management level and traceability capabilities in case of problems, so it requires careful checking.
Choose a Reliable Manufacturer
From a long-term cooperation perspective, choosing a reliable manufacturer is often more important than a single purchase. A reliable manufacturer should first be certified to ISO 9001 or the stricter ISO 13485 medical quality management system.
You should comprehensively examine their raw material supply stability and traceability, silicone molding process, quality testing capabilities, and packaging options. What’s more, confirming whether the manufacturer possesses a Class 10,000 or Class 100,000 cleanroom is important for ensuring the hygiene of medical-grade silicone.
FAQ
How Long Does Medical-grade Silicone Last?
Medical-grade silicone is very durable and can maintain stability for a long time under normal use conditions. Its lifespan depends on its intended use, the chemicals it comes into contact with, and the temperature, etc.
External medical devices such as silicone catheters are usually for single use, so their lifespan is generally no more than one month. Silicone implants focus on long-term safety and can have a lifespan of over 10 years. Please refer to the instruction manual or consult the manufacturer for specific details.
Does Medical-grade Silicone Produce Microplastics?
Medical-grade silicone is not plastic, so it doesn’t produce microplastics. Under normal use, the risk of microparticle formation from medical-grade silicone is minimal. What’s more, ISO 10993 includes tests for microparticle shedding and degradation.
Long-term abrasion or rough cutting can cause direct mechanical damage to medical-grade silicone, resulting in microparticles. But due to silicone’s bio-inertness, the harm caused by these microparticles is far less than that caused by microplastics.
Are Colored Medical-grade Silicones Safe?
Colored medical-grade silicone is safe as long as it uses pigments that meet medical standards. You can request pigment information from the manufacturer to confirm that the pigments used are also certified to medical-grade safety standards.
But you need to be aware of whether the manufacturer uses overly bright colors or uses dark colors to cover up quality issues such as impurities, and whether the pigments are firmly bonded to the product. These are the factors that could make colored medical-grade silicone unsafe.
Are There Any Potential Risks Associated with Medical-grade Silicone?
Medical-grade silicone can indeed cause inflammation and allergies such as swelling and itching, but these are rare. What’s more, medical-grade silicone products like breast implants carry a risk of bursting due to external force and may potentially cause breast implant-related disease (BII), a currently controversial condition.
Is LSR or HCR Better for Medical-grade Silicone?
Both have their advantages, and you can choose according to your needs. LSR offers higher precision and transparency, making it more suitable for manufacturing medical seals, complex, tiny, or very thin components. If you require products with high mechanical performance requirements, HCR, which has good mechanical strength, is a wise choice.
What’s more, LSR product manufacturing is highly automated, but its molds are more expensive, making it more suitable for large-batch orders. HCR molds are cheaper, but require manual assistance in production, making them suitable for small-batch orders.
Final Thoughts
High-quality medical-grade silicone is important for ensuring the safety of medical products. Legensilico is a medical-grade silicone manufacturer with over 20 years of experience, and can supply you or customize products that meet ISO 10993 and USP Class VI. Contact us to learn more about medical-grade silicone!
