Is silicone biodegradable?

Is silicone biodegradable and eco-friendly? It seems that lately silicone is everywhere. You’ve probably been getting a million ads on Instagram for fancy silicone toothbrushes and have noticed the sudden proliferation of silicone sponges and bakeware in stores. Maybe you already own one those super convenient collapsible silicone containers or regularly use a silicone spatula to avoid scratching your cookware.

Silicone is a relatively new material and, because of this, it’s a bit of a conundrum for most people: Is it plastic? Is it a rubber? is it safe? And – more importantly – why does it make everything look like a bright, colorful children’s toy? It usually gets marketed as a safer, greener alternative to plastic, and manufacturers from all industries – aerospace, automotive, construction, consumer goods, and medicine – sing never-ending praises to its superior durability.

The truth is, however, that although silicone is a much safer alternative to plastics or rubbers, that it’s much more durable than similar materials and that it’s an ideal choice for things such as aircraft and automotive components or medical equipment applications, it just hasn’t been around for long enough for us to know with a high degree of certainty whether it’s 100% safe for humans and the environment.

While that may make some people suspicious of silicone, it is for those same reasons that we shouldn’t be too quick to write this material off until we study it more extensively as it could be a big part of the solution to the global crisis with plastic pollution.

What is silicone?

First thing: let’s get our spelling right. Silicone is the material that we are currently talking about. It’s a synthetic polymer used to make things such as homewares, personal care products and medical tools such as breathing masks. Silicon is the element from which the silicate family is derived. It’s one of the most abundant elements in the universe and it’s present in rocks, sand, silicate minerals, among other things. From it we make glass, porcelain and the aforementioned silicone polymers. Highly purified forms of silicon are used to make semiconductors and the electronic chips found in phones, computers and other electronics.

So what is silicone? In short, it’s a bit in between plastics and rubbers. All three of these materials – plastic, rubber, and silicone – are polymers with the distinction that rubber is a naturally-occurring polymer while plastic and silicone are synthetic polymers.

The difference between plastic and silicone is that plastic is made from petrochemicals and requires additives that give it specific characteristics while silicone is made from the naturally occurring element Silicon bound to atoms from other organic elements such as Carbon, Hydrogen, Oxygen, and Nitrogen. Silicones – known as polymerized siloxanes – are an extremely versatile family of compounds that have a wide range of applications: from sealants, lubricants and construction materials, a dizzying amount of consumer goods, and even cosmetics.

This video does a wonderful job explaining how different types of silicones are made.

Is silicone safe?

The short answer is: “yes” but there are some important things to consider. While the evidence on whether silicone reacts with or migrates into food is still inconclusive, most sources agree that silicone is a chemically inert and stable material that is not toxic. There have been some studies that have found very small amounts of siloxane that have migrated into food after exposing silicone objects to powerful solvents for extended periods.

While this may make a few people feel a bit uneasy about having silicone products in contact with their food, it’s important to remember that the conditions to which silicone was subjected in these experiments were much more extreme than any of those to which it is likely to be exposed to in most domestic settings.

Although more research on the matter is needed, the scientific community generally agrees that the small quantities of siloxanes that may migrate to into food or drink do not pose a significant risk for humans. Health Canada, the Canadian federal health agency, states that, based on all available scientific evidence, they have concluded that siloxane materials do not pose a risk for humans or the environment and that the quantities of these materials that are currently present in the environment are very low and shouldn’t be a cause for concern.

Is silicone eco-friendly?

Again, the answer is in between a yes and a no but leaning closer to a “yes”. The issue is that silicone is a synthetic polymer and there is simply no such thing as a 100% eco-friendly synthetic material. Manufacturing, transportation, marketing, and packaging always add processes and components that are not as planet-friendly as the product itself may be.

Silicone has two big advantages that make it a much more eco-friendly option than plastic, rubber and other man-made compounds and that is its composition and its durability. On the ingredients side, its main component comes from silica, which is found naturally in sand, quartz, gravel and similar materials. These materials are then heated at very high temperatures and put through different processes to alter their chemical properties depending on the products that will be manufactured from them.

Using elements and minerals that are easily extracted and pose a low risk of environmental pollution is, by far, a much preferable option to the petroleum-derived hydrocarbons needed to make plastic or synthetic rubber. Still, although making useful and long-lasting items out of sand sounds like the greenest, most ideal fantasy ever, there are consequences to extracting large amounts of sand and minerals to make products such as silicones or glass.

Though it seems unlikely, sand is one of the most-used resources on the planet. It’s mixed into concrete to make roads, buildings and homes; used to fill empty areas so that buildings and other objects can go on top of them and; make islands larger or make new artificial sand islands; and, lately, even to replace more sand that has been eroded. The demand for sand to mix into concrete for construction plus other applications such as the manufacturing of silicon chips, silicone consumer products, and glass has created a global sand shortage *Why the world is running out of sand – BBC Future*.

Since the sand that most manufacturers consider useful for these applications is the one that has been shaped by water and not winds such as the one found in deserts, this means that riverbeds and ocean floors are getting dredged and eroded at an alarming pace that affects everything from wildlife and soils to the very course that rivers follow.

Not everything is bad news, though, thanks to silicone’s second main advantage: durability. Since it’s such a stable compound, silicone can withstand a much wider range of wear, tear and extreme conditions. Materials that have longer lives and don’t require frequent replacement are always preferable to less durable ones as this means that fewer resources are needed to meet the demand for them and that we can also make fewer quantities of them.

As we have explained, silicone’s inertness also means that its particles do not migrate the same way that those in plastics and other synthetic materials do to accumulate in human bodies or the environment. You can use silicone products with a high degree of confidence that they are not contaminating food, polluting water sources or making you sick.

Is silicone biodegradable?

So let`s find out if is silicone biodegradable. As you may have guessed, a material that can withstand extreme heat, cold and pressure is not biodegradable. In fact, silicone doesn’t decompose at all. It is, however, recyclable but most people don’t know this, partly because it’s still such a misunderstood material and also because most recycling programs do not accept it. 

There are a few downsides to silicone’s recyclability. First, same as plastic, it is not infinitely recyclable. Second, recyclers can only downcycle it into silicone oils so, for example, you cannot make a new muffin mold from recycled silicone. Third, most people will simply dispose of silicone the same way that they dispose of other trash and it will go to landfills. The good news is that, since silicone doesn’t decompose and its components have a very low migration rate, the environmental impact is significantly reduced in comparison to plastics.

There are still not a lot of companies recycling silicone but it’s a sure fact that as the usage of this material becomes more widespread, recycling it will become easier. For now, it’s best to choose products from companies that have take-back programs or find a company that collects silicone waste such as Terra Cycle TerraCycle so that you can be sure that your silicone waste is being properly recycled.

What are the benefits of silicone products?

There are a lot of benefits to choosing items made out of silicone over rubber, plastic and other materials, especially for items that you will be using around the home:

  • Durability

You can rest assured that any silicone product that you purchase will last you for a very long time if you take good care of it. Silicone’s high resistance to stress, pressure, extreme temperatures and UV light make it a much longer-lasting option than either rubber or plastic while removing the risk of breakage that glass poses and the damages that metal surfaces may suffer. It can be subjected to both flaming hot and freezing cold temperatures for extended periods without its molecular structure suffering any changes.

  • Versatility

Silicone is an extremely versatile material that can be used in a multitude of settings and conditions. Being resistant to such a wide range of conditions makes it an excellent option for those who are looking to downsize their kitchen and reduce their consumption of new items by using multipurpose products that are meant to last for longer and resist damage better.

  • Safety

For now, silicone is the safest material available that still holds the useful properties of plastics and rubbers. It’s inertness means that it will experience little to none migration of particles, which makes it especially beneficial for replacing plastic or synthetic rubber items for babies and children such as bottles, nipples, pacifiers, cups or plates.

Food-grade silicone is impermeable and does not absorb odors, oils or liquids meaning that cleanup will be easy and not require the usage of harsh surfactants or chemicals. This is especially useful around the kitchen and especially for food storage containers whose surfaces will spend a prolonged period in contact with food and may otherwise develop unpleasant odors, staining or discoloration.

Another reason why silicone is so safe is that it doesn’t transfer heat well. Because of this, it’s become a very popular material for items such as spatulas, bakeware, panhandle grips and oven mitts. It’s also used for containers and cups that can be refrigerated, frozen and are microwave-proof with no cause for concern regarding breakage, leakage or any other type of damage.

Our picks for the best and most useful silicone products:

Read on below to find out what we think are the best silicone products:

1. Silicone Spatulas

Want to know the secret to Gordon Ramsay’s internet-famous perfect scrambled eggs? Use a silicone spatula! These spatulas are some of the most useful and versatile kitchen tools you can purchase: they resist heat to up to 500F, they’re super flexible and nearly impossible to break and they will keep your pots and pans – especially non-stick ones – free from scratches. They’re perfect for cooking, baking.

2. Collapsible Bucket

A super handy, multi-purpose bucket for people with limited space and even better for camping and outdoors. Use it for mopping, hand washing, dishwashing, carrying water, and even as a makeshift drink cooler for a picnic.

3. Zip Top Bags

These reusable silicone bags eliminate one of the largest sources of kitchen plastic waste: plastic containers, cling wrap, and plastic zipper bags. And they’re not just for storing food: you can put them in the microwave, run them through the dishwasher, put them in the oven, and even use them for sous-vide cooking. Each bag creates an airtight seal that does not allow liquids to enter or exit it, making it perfect for storing liquids such as soups or marinating meats.

4. Silicone Food Savers

Ever find yourself wondering what to do with that half onion leftover from last night’s guacamole? These nifty food huggers will help you keep it from rolling around and drying out in your fridge until it’s time for you to use it again.

5. Reusable Straws

If that set of reusable metal straws that you bought last year after reading about turtles choking on plastic ones is killing your teeth, then this softer silicone version may be a much better option for you. Another thing your mouth will be very happy to know is that the straws in this set are much thicker in diameter than regular straws, which will take the struggle out of trying to sip your smoothies through a tiny, stick-thin straw.

6. Ice Cube Trays

You won’t struggle for what feels like an hour trying to wiggle out a tiny ice cube from a plastic tray again after you try out this super flexible silicone version.

7. Whiskey Ice Cube Trays

Up your home bar game with these oversized, slow-melting ice cubes. They’re perfect for whiskey and craft cocktails or just to keep any drink cold without making it watery.

8. Collapsible Water Bottle

This already super light bottle gets lighter and smaller as you drink from it – we can’t think of better motivation to drink more water! It’s great for keeping it ready to be refilled in your purse, gym bag, or backpack so that you never have to resort to purchasing a bottle of water last minute ever again.

Give silicone products a chance

I get it. Silicone is still far from being perfect. It is always preferable to use items made out of infinitely recyclable materials such as metal or glass or compostable ones like organic fibers and wood whenever possible. But, as I have shown you above, there are plenty of other items that just can’t be made from any infinitely recyclable or organic materials and that are usually made from plastic that can easily be replaced by silicone.

Switching to a durable and inert material that will require less frequent replacement and that poses much fewer environmental risks than plastics or rubbers will make a big difference in reducing waste and the demand for virgin plastics and could become one of the keys in solving the current environmental emergency that we have put our planet in.

I am confident, as technology progresses, silicone manufacturing will become cleaner and that, as the public becomes more educated about this material, recycling will become easier and more widespread.