Silicone products are commonly used in our daily life, such as silicone kitchenware, and baby bottle nipples, you can also find them in cosmetics and personal care products, everywhere.. and it is considered to be the best alternative to other materials such as plastic.
Though it is consistently marketed that silicone is a safe material both for humans and nature, many people still have doubt that: is silicone safe for us? To answer this question, we should know what silicone is and where it comes from.
So what is silicone? What is silicone made from?
Wikipedia says: Silicone can be used as a basic sealant against water and air penetration. Silicone, also known as polysiloxanes, are polymers that include any synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms, combined with carbon, hydrogen, and sometimes other elements.
Silicone is an elastomer (rubber-like material) composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Wacker & Dow, as two giant chemical businesses all, marked that silicone is derived from sand.
Wacker: Silicones are made from quartz sand, a raw material available in practically unlimited quantities.
Dow: Derived from sand, Silicones exist as – Derived from sand, Silicones exist as Volatiles Volatiles Fluids Gums Elastomers Elastomers Sealants Sealants Resins.
Silicones exhibit many useful characteristics, including:
- Low thermal conductivity
- Low chemical reactivity
- Low toxicity
- Thermal stability (constancy of properties over a wide temperature range of −100 to 250 °C).
- The ability to repel water and form watertight seals.
- Does not stick to many substrates, but adheres very well to others, e.g. glass.
- Does not support microbiological growth.
- Resistance to oxygen, ozone, and ultraviolet (UV) light.
- Electrical insulation properties.
- High gas permeability: at room temperature (25 °C), the permeability of silicone rubber for such gases as oxygen is approximately 400 times that of butyl rubber, making silicone useful for medical applications in which increased aeration is desired. Conversely, silicone rubbers cannot be used where gas-tight seals are necessary.
Is silicone safe?
Silicone shows excellent characteristics, but is silicone safe for humans or is silicone environmentally safe? That’s a big question because there is no clear answer. Opinions differ between different reports.
Opinions on potential dangers of silicone include:
- The potential for leaching at high temperatures
- Fillers used in lower-quality silicone
- Potential odor during high-temperature use
These dangers are not proven and not scientifically supported. For opinion 1, Potential leaching at high temperature, the word “HIGH” is undefined, to what standard will silicone be leaching? no studies answer it. Be aware that silicone products are molded under the temperature of 180~200℃ to make raw silicone material fully vulcanized, so molding production is also called vulcanizing production.
For the second point, yes it’s common for the material supplier to add fillers in silicone, thus it’s widely acknowledged that if silicone turns white at stretch, then it is bad silicone not safe. This opinion is one way for silicone material checking, but it is too absolute, only Pure silicone won’t turn white. Silicone turns white only says there is filler in the material, but it doesn’t mean silicone is not safe, for FDA-approved silicones, turn white but they are food safe. And this opinion gives customers the wrong guidance in material selection because they turn to require material not turn white without considering the application of products, for example, the Magic silicone gloves which are extremely popular, some customers require material not turn white, it will be a waste to use pure silicone for wash gloves, pure silicone is much expensive and hard for demolding, which cause cost increase.
For point 3, the odor of silicone mainly comes from the vulcanizer added, normally the vulcanizer should be volatilized during mold production, but sometimes there may be residue which makes silicone smelly, by using a better vulcanizer such as Platinum or taken post-cure, these residues will be eliminated, the products will be odorless. The attention that post cure is putting silicone products in oven-baked at a temperature of 200℃ for 2 hours, an adequate high-temperature process is a way to get rid of vulcanizer, so potential odor during high-temperature use is a wrong surmise.
Positive opinions on silicone safety are :
The results of this continuous research and testing demonstrate that silicones are safe in their diverse and important applications, which contribute enormously to comfort, safety and enjoyment in our daily lives.
Silicone is a synthetic rubber which contains bonded silicon (a natural element which is very abundant in sand and rock) and oxygen. Cookware made from food grade silicone has become popular in recent years because it is colorful, nonstick, stain-resistant, hard-wearing, cools quickly, and tolerates extremes of temperature. There are no known health hazards associated with use of silicone cookware.Silicone rubber does not react with food or beverages, or produce any hazardous fumes.
Global Silicones Council has done more than 1,000 studies over many decades have been conducted to assess the safety of silicones.
Confirmed silicones’ safety both for human health and the environment
One thing is for sure, silicone is much better than plastic, both for the body and nature.
One suggestion: Buy your silicone products in FDA or LFGB approved.
Is silicone safe or not? what’s your opinion?