Is the silicone material used in baking tools and medical instruments toxic? Do silicone parts cause any potential food safety risks? If you have these questions, please follow this guide to learn more about the safety of silicone. This will surely help you choose safe silicone products and guide your customers on their proper use.
Is Silicone Safe?
Silicone is safe, but not all silicone is safe, and the safety of the same type of silicone can vary depending on its application.
First, let’s clarify a concept: use the appropriate silicone for the appropriate purpose. Using industrial-grade silicone for food or using silicone products without following the instructions is inherently problematic. With that in mind, food-grade and medical silicones are non-toxic. Low-quality and industrial-grade silicones contain substances harmful to the human body.
Does Silicone Contain Harmful Substances?
What’s in Silicone?
Silicone, or silicone rubber, is a special type of synthetic rubber. It is a semi-inorganic, semi-organic polymer material. Silicone molecules have a backbone composed of silicon and oxygen atoms, with organic groups attached to this backbone. These backbones with attached organic groups connect to form a silicone structure with a three-dimensional network.
Silicone is a material that is harmless to the human body, but evaluating the safety of a material involves more than just looking at the material itself. The purity of the raw materials, the types of intermediates, and the substances and additives used in the silicone manufacturing process all affect its safety.
Impurities That May Exist in the Raw Materials
The initial form of this complex structure is actually a simple inorganic substance: silicon dioxide. You might be unfamiliar with this substance, but it is actually the main component of sand, a natural material. In fact, silicone production uses quartz sand with fewer impurities.
High-quality silicone uses very pure quartz sand, preventing harmful chemicals from entering the silicone structure from the outset. In contrast, some manufacturers of inferior products focus on higher economic returns and don’t maintain such strict control over the quality of raw materials.
D4, D5, and D6
These three siloxanes are intermediate products formed during the manufacturing process of silicone. The production of silicone involves processes of heating quartz sand, grinding, catalytic reaction, hydrolysis, polymerization, and vulcanization, and these intermediate products are generated after the hydrolysis step.
D4, D5, and D6 are considered special because they pose a risk of gradually accumulating in the body and can interfere with hormones to some extent, thus affecting human health.
In high-quality silicone materials such as food-grade silicone, their content is strictly controlled. The EU REACH regulation requires that the residual levels of D4 and D5 in detergents and cosmetics do not exceed 0.1%. If you want to ensure the safety of your products, please be sure to purchase high-quality silicone materials and products.
Peroxide
Silicone rubber vulcanized with peroxides may retain peroxide catalysts and produce byproducts that are harmful to the human body. These byproducts are volatile and disappear from the silicone after the high-temperature curing step, but some residue may exist.
Therefore, silicone rubber used in food production or medical applications typically employs a different processing method: platinum-catalyzed vulcanization.
The catalyst used in the platinum vulcanization reaction is a platinum salt, which, even if it remains in the silicone after the reaction, does not produce harmful effects upon contact with the body. Furthermore, the platinum vulcanization reaction does not produce toxic byproducts.
The problem with this vulcanization system is its higher cost. The materials are more expensive, and the high temperatures required during the process consume more energy.
Plasticizers such as Phthalates
Phthalates are common plasticizers that are frequently added to PVC to improve its properties. Materials using phthalates as additives have a better appearance and become more flexible.
One reason why plastics are toxic for humans is the addition of these plasticizers. During contact with food, especially at high temperatures, phthalates can pollute food and ultimately have harmful effects on the human body.
Low-quality silicone and industrial-grade silicone may contain these toxic plasticizers, making them absolutely unsuitable for applications of medical, pharmaceutical, or food production.
BPA
Bisphenol A (BPA) is another widely criticized additive found in plastics. While it improves properties such as wear resistance, it can easily leach out from coatings or within the material itself. BPA entering the human body can seriously interfere with babies‘ growth and development, and reproductive system health.
Silicone usually doesn’t contain BPA, but for the safety of your product, it is best to purchase silicone products labeled “BPA Free.”
PFAS
As long as you purchase high-quality silicone products, you don’t need to worry about your baking tools containing PFAS. Firstly, the production of food-grade and medical-grade silicone does not involve the risk of generating PFAS. Secondly, PFAS are often found in non-stick coatings, such as those used on non-stick pans. Silicone itself is not easily adhered to by food, eliminating the need for such coatings.
Silicone used for industrial purposes may have this substance added to enhance its performance further.
Heavy Metal Ions
Low-quality and industrial-grade silicone may be added industrial-grade pigments during manufacturing, which may contain heavy metal ions such as chromium and lead. If they enter the body, they can cause a series of damage to the nerves and organs.
Standards set by the FDA and LFGB require food-grade and medical-grade silicone products to have extremely low levels of heavy metal ions. As long as the product has passed these safety certifications, you don’t need to worry about this issue with the silicone.
The Performance of Silicone at High and Low Temperatures
Using high-quality silicone within the specified temperature range will be a safe choice.
Silicone is a material with a wide temperature range, capable of working normally in environments from -60 to 230°C. While temperatures near the extremes may cause a slight decrease in its flexibility and other properties, it maintains its stability and doesn’t produce toxic substances.
So it’s safe to use a microwave oven to heat silicone utensils within the temperature tolerance range or to wash silicone products in a dishwasher. Of course, this is under the premise that the silicone itself doesn’t contain any toxic chemicals, and the following instructions are also the same.
Chemical Inertness of Silicone
Due to its molecular structure, silicone is not a material that easily reacts with other chemicals. It has excellent resistance to common cooking and baking ingredients such as baking soda and vinegar.
The regular use of wine in food production processes doesn’t cause any part of the silicone to dissolve. In the medical field, alcohol is even used to disinfect silicone products.
You don’t need to worry about toxic products being formed when food or substances from the human body come into contact with high-quality silicone.
Silicone does have its limitations and is not suitable for all applications, such as those involving fuels and concentrated acids, but these situations generally only occur in industrial production.
Biocompatibility of Silicone
Silicone has excellent biocompatibility. This means it is less likely to cause excessive immune responses such as allergies, and after testing, it can be used as an implant and remain in contact with human tissue for extended periods.
Allergies are a serious threat in the medical and cosmetic fields. Allergens in food and medications can cause symptoms ranging from diarrhea to anaphylactic shock in consumers. Except for a very small number of individuals allergic to silicone, silicone is rarely recognized by cells as an allergen. Medical-grade silicone is gentle and non-irritating, and even when used as a wound dressing, it does not cause strong inflammation.
So you can confidently use food-grade silicone parts or products in your food production lines, restaurants, or workshops.
For medical materials, silicone also has the advantage of not easily adhering to patient tissues and wounds. You can safely remove the silicone without causing secondary damage. It also does not easily cause blood clots.
Long-term Stability of Silicone
Silicone is a very stable material. External factors such as ultraviolet light and ozone have little effect on it. Although it will inevitably age with increased years, losing its safety over time, this process usually takes a long time.
With proper use and maintenance, silicone products have a lifespan of 10 to 20 years, but this depends on the manufacturer’s specifications. If the silicone is of high quality, this lifespan can even extend to over 30 years. Within its lifespan, you can enjoy the safety that silicone provides.
Cleanliness of Silicone
Silicone itself is not a suitable environment for bacteria or mold growth. Unlike wood, it doesn’t absorb water or other chemicals, preventing mold growth caused by exposure to moisture for a long time. The smooth surface of silicone products is easy to clean and less likely to retain dirt.
If you are particularly concerned about hygiene, you can also purchase silicone products that contain antibacterial agents such as silver ions. A suitable amount of silver ions is harmless and can control the number of bacteria to a certain extent.
What’s more, high-quality silicone can be sterilized by soaking it in hot water for a period of time, further ensuring hygiene. Medical-grade silicone can be sterilized using various methods, including high-pressure steam sterilization, to kill any potential pathogens.
The Safety of Different Grades of Silicone
Due to these differences, different types of silicone have their own levels of safety and corresponding uses:
Ordinary or Industrial-grade Silicone
Safety
Ordinary or Industrial-grade Silicone may contain harmful additives such as BPA, phthalates, talcum powder, industrial dyes, and PFAS. What’s more, peroxide catalysts may remain from the manufacturing process. When heated or in contact with food or the human body, these harmful substances may leach out.
Uses
They are not suitable for medical, healthcare, or other products that come into direct contact with food, and are primarily used in industrial manufacturing, construction, aerospace fields, etc.
Food-grade Silicone
Safety
Food-grade silicone is free from toxic additives such as BPA, BPS, and PFAS. During production, manufactures uses a platinum-catalyzed process for curing, resulting in no toxic byproducts. Its color is from food-contact grade pigments, such as titanium dioxide, which is safe.
Food-grade silicone doesn’t react with common chemicals found in food or produce volatile organic compounds (VOCs) within its operating temperature range.
Standards
- FDA 21 CFR Part 177.2600
- LFGB(stricter than the FDA)
Uses
It’s safe for the products that come into direct contact with food, but not suitable for medical use. Its widly using in baking supplies, such as silicone baking molds and silicone spatulas. Refrigerator door seals and ice cube molds are usually made of food-grade silicone.
Pet supplies are also an emerging application area for food-grade silicone. Silicone slow-feeding bowls are soft and safe while providing pets with enjoyment.
Medical-grade Silicone
Safety
Building upon food-grade silicone, medical-grade silicone offers further safety. In addition to being free of harmful additives, medical-grade silicone should undergo specific safety testing based on its intended use to ensure it will not adversely affect human tissues and fluids.
Its high-temperature resistance and other properties have also been enhanced. They can be thoroughly sterilized using various methods, including autoclaving and ethylene oxide (ETO) sterilization.
Standards
- ISO 10993
- ISO 13485
- USP Class VI
Tests that may need to be passed
- Cytotoxicity testing
- Sensitization testing
- Genotoxicity testing
Uses
- Pharmaceutical production: silicone tubing and biological product packaging
- Care products: tongue cleaners
- Short-term contact: breathing masks, infusion tube
- Long-term contact: indwelling urinary catheters, scar patches
- Long-term implantable: pacemakers, breast implants
Factors that May Cause Silicone to Become Toxic
Unsuitable Temperature
Using silicone outside its temperature tolerance range can cause serious safety problems. At high temperatures, it doesn’t melt into a liquid like plastic, but it actually degrades, potentially releasing toxic chemicals.
Please note that placing silicone too close to the heating element of an air fryer or dry-baking it can produce similar effects.
Being too close to the heating element can cause localized overheating of the silicone, so pay attention to the position of silicone products during use. If you don’t fill all the parts of a silicone mold when baking, you should add water to the empty compartments.
Never use silicone products on a barbecue grill or put them directly over a flame！
Contact with Corrosive Substances
Although silicone has excellent chemical inertness, it is still powerless against highly corrosive substances. Don’t use silicone products to store or transfer strong acids, strong bases, or powerful cleaning agents. The safety of silicone after it has been corroded can’t be guaranteed.
Aging and Damage
Cutting the silicone, damaging the silicone surface with sharp objects, or aging due to long-term use can make the silicone unsafe. This may expose certain chemicals within the silicone or the materials it originally encased. Cracks or scratches can also easily become breeding grounds for bacteria during repeated use.
If you notice that the silicone surface is excessively worn, cracked, or severely discolored, you should replace the product promptly.
Risks that May Arise from the Wrong Use or Use of Low-quality Silicone
Allergic Reactions
Due to the presence of impurities and toxic additives, contact with low-quality or industrial-grade silicone is more likely to cause skin irritation and swelling in body parts such as the eyes.
If this silicone comes into contact with food, the harmful chemicals ingested can further cause digestive allergic reactions such as vomiting and stomach pain
Allergic reactions caused by silicone implants are even more dangerous. They not only cause immune system disorders such as rheumatoid arthritis, but also fever, chest pain, and blood clots, which can seriously threaten your customers’ lives.
Release of Toxic Substances
Burnt or overheated silicone can produce volatile toxic gases or fumes. Inhaling these fumes can not only irritate the respiratory tract and cause discomfort but may also lead to dizziness and nausea.
Long-term Security Risks
Prolonged use of unsuitable or use silicone products in the wrong way can cause long-term health damage. Many common industrial additives and fillers can disrupt the body’s hormones, causing growth and development to deviate from their original way, and even triggering cancer.
How Can I Buy Safe Silicone Products?
Compliant with Laws and Standards
When purchasing silicone and its products, pay special attention to whether it has obtained the corresponding FDA certifications for medical-grade or food-grade silicone. These regulations and standards are the fundamental basis for ensuring the safety of silicone. You can also request a test report from the manufacturer to obtain more detailed product information.
Avoid Buying Products at Unreasonable Prices
Silicone sold at significantly below-normal prices may be toxic. To save costs, manufacturers may use cheaper raw materials and fillers, or even recycled silicone. At worst, the silicone you buy may not be pure at all, containing other synthetic rubber materials.
Observe and Smell
Qualified food-grade or medical-grade silicone generally has no odor. If you smell a pungent odor when you receive the product, the silicone product may contain toxic chemicals.
One of the main differences between high-quality silicone and inferior silicone is their tensile strength. You can stretch the silicone, and if you observe it turning white after stretching, or exhibiting uneven thickness after returning to its original state, it indicates poor-quality silicone.
Choose a Trustworthy Brand
Choosing a trustworthy brand greatly helps in purchasing sufficiently safe silicone. Years of production experience and professional quality control not only ensure the safety of your products and production, but also minimize variations between different batches.
FAQ
Is Silicone Safe For the Environment?
Silicone is not an entirely environmentally friendly material, but its impact on the environment is undoubtedly smaller than that of plastics. The production process of silicone requires a large amount of energy, but its very long lifespan can offset this negative impact, greatly reducing rubbish. Although silicone can be recycled by specialized recycling companies, this recycling method has not yet become widespread.
Does Silicone Produce Microplastics?
Silicone doesn’t produce microplastics, and the small particles it produces after damage or aging have a much smaller impact on the environment and organisms than microplastics. These small particles are more easily broken down and don’t cause the serious pollution problems that microplastics do.
Is Silicone Sealant Toxic?
Unused silicone sealant contains solvents and hardeners that are harmful to humans. Once cured, these substances will evaporate from the sealant or remain sealed inside, and contact with them generally doesn’t pose a serious safety hazard.
During the curing process, please always wear gloves, goggles, and other protective equipment. At the same time, please ensure that the room where silicone sealant is used is well ventilated so that toxic volatile substances can be carried away.
Final Thoughts
Whether silicone is toxic depends on its quality and grade. Legensilico offers a variety of high-quality silicone products that are FDA certified, ensuring the safety of your production and products. With over 20 years of experience in silicone manufacturing, we better understand your needs and offer customization services in areas such as size and color. Choose us now for peace of mind！
