If you are going zero waste, one of the popular pieces of advice you'll get is to avoid plastic. Now, you’ll find many other materials people believe would best replace plastic, one of which is silicone. The material is durable, flexible, and able to withstand extreme temperatures. Silicone has exceptional functionality but is silicone eco-friendly, and is it better for the environment? That's the question we try to answer in this article.
The global silicone industry was worth 14.4 billion USD in 2020, and researchers expect it to grow at a CAGR of 4.3% between 2021 and 20284. But that shouldn't come as a surprise; silicone is very popular and versatile.
Silicone can come in many forms, including silicone oil, gel, liquid, solid, or rubber forms. They use silicone-based products in the electronics, textiles, healthcare, beauty, automobile, and renewable energy industries. There are three grades of silicone; food-grade, industrial-grade, and medical-grade silicone.
As an end-user consumer, common silicone plastic products you'll find around you include eco-friendly phone cases, silicone menstrual cups, bakeware, food containers, and silicone cookware.
Silicone is fast becoming a material of choice for kitchen utensils, food storage containers, and more. Silicone cooking utensils won't leave a scratch on your pans. The material also works out nicely for reusable food packaging, with silicone bags and containers beating single-use plastic products like baking mats or ziplock bags.
A recent report revealed that the application of silicone in the textiles industry5 as a softening agent, hydrophobic coat, anti-foaming agent, etc., is growing. So you probably own several silicone items of fashion already.
Silicone products are popular with plastic-free enthusiasts. They believe silicone causes less waste, reduces plastic pollution, and is completely safe. But is that all greenwashing or is silicone eco-friendly indeed?
To determine if silicone is eco-friendly, we look at how it impacts the environment throughout its life cycle, from the extraction of its raw materials to how it is used and disposed of. We also look at its possible effects on our health.
The primary raw material for silicone is silica or silicon dioxide, primarily sourced from sand. Silica, carbon, oxygen, and hydrogen make up the chemical composition of silicone, and whereas silica is not renewable, at least it is available in abundance.
Some people claim that silicone is organic because of its sandy origin. However, the process of extracting silicone from silica requires the use of carbon and hydrocarbons extracted from natural gas and oil. That makes silicone a synthetic material. So while plastic is made entirely from crude oil, silicone combines some petrochemicals with its key ingredient –sand.
It is pertinent to note that the materials for producing silicone do not exclude petroleum. What's more, silicone manufacturers don't turn off the processing furnace because turning it off and on again would consume more fuel. Therefore, the cons that we associate with plastic, such as consumption of non-renewable natural resources and crude oil carbon emissions, apply, at least in part, to silicone too.
The absence of phthalates and BPA in silicone is one of the reasons many people consider silicone a better alternative to plastic. Health Canada says food-grade silicone is safe for cooking and storing food as it doesn't react with food or beverages. Even the United States Food and Drug Administration approves silicone use6.
But silicone does contain synthetic chemicals, although it doesn't leach out chemicals easily. It is inert and doesn't react with other chemicals. However, research has shown that a chemical compound, siloxanes, can leach out at temperatures above 300° F (149° C)2. This is an important consideration for people who are using silicone oven trays or cupcake molds. Food containers and other silicone products not exposed to very high temperatures are safe.
In trying to assess the risks of human contact with siloxanes, scientists observed that the toxicity of siloxanes depends on the different types of siloxane compounds1. Low molecular weight silicones like silicone resin gels, silicone rubber, and oils are more likely to threaten human health. Those types of silicone have been linked to cancer, immune system damage, skin irritations, eye problems, and fetal defects. One study showed that silicone gel could kill human cells3.
Cheaply manufactured silicone usually contains plastic or chemical fillers used to reduce production costs, which may have toxins in them. An easy way to check if a silicone product contains fillers is to twist or pinch it. If it is pure silicone, the color will remain the same, but if it has fillers, the color will change.
People value kitchen utensils made with silicone for their durability. They can withstand freezing temperatures and extreme heat without cracking or melting. You can use silicone products for decades as long as you use them correctly. They won't crack, break, or get discolored easily.
Silicone products don't easily damage, so you won't have to buy replacements often. You can even save storage space by folding collapsible silicone water bottles without worrying about damage. There are many other silicone products like that. You'll find that high-quality silicone products are not discarded as much as plastic products. The durability makes silicone result in less waste over time.
The material is not indestructible, and its rubbery form can tear if it isn't kept away from sharp objects. Abrasives can easily damage silicone, and although it can withstand extremely high temperatures, it isn't fire-resistant.
For a material to be biodegradable, microorganisms must act on it, breaking it down for food, and producing soil nutrients. Biodegradable materials are organic, and non-biodegradable materials are synthetics. So is silicone biodegradable? No.
Silicone is not biodegradable because it is a synthetic material, and microorganisms cannot break it down. They do not recognize this material as food. It shares this characteristic with plastic, but unlike plastic, it doesn't break down into microplastics over time.
One thing, however, is that silicone breaks down eventually. It breaks down into inorganic matter after a while. Silicone decomposition could take up to 500 years, thanks to its excellent durability. Sending silicone to the landfill is wasteful and not the best disposal method.
However, it is better than plastic in the sense that we don't have to worry about microparticles of silicone floating around in the ocean and poisoning fish. Silicone doesn't become toxic or leach toxins into the environment as it breaks down because it is chemically stable.
Silicone is recyclable and can be made into mulch or industrial lubricant. However, you cannot recycle unwanted silicone products through the curbside recycling system. You'll need to find specialized silicone recycling centers. Try TerraCycle if there are no silicone recyclers close by that you can conveniently ship to.
It would cost you some money, but a TerraCycle zero waste box allows you to recycle almost anything. It is possible to recycle silicone at home, but you would need expert knowledge and special instruments for that. If you are down for recycling silicone at home, you could help others in your community do the same. You would be making a significant impact.
The process of recycling silicone is not quite as polluting as recycling plastic as it is possible to recycle the material multiple times.
For a deeper dive: Is Silicone Recyclable? How to Correctly Recycle Unwanted Silicone
Silicone is not the patron saint of eco-friendly materials; however, it outperforms plastic in many ways. Depending on how long you use a silicone product and how you dispose of it, it could even be better for the planet than wood or paper alternatives.
If you use a silicone cooking spoon for ten years and recycle it at the end of its useful life, you would have a smaller carbon footprint than if you replaced a wooden spoon every year.
So should you use silicone products? Yes. But only if you intend to use them for a long time and will recycle them when they are no longer useful. Considering how silicone is made, that would be the only way to make the environmental costs count.
Additionally, you should only buy good quality silicone products so that you can enjoy their durability. Also, silicone products are safer for your health than plastic.
If you are looking for greener options than silicone, consider bamboo, steel, glassware, ceramics, recycled paper wraps, and sustainable fabrics. Be reminded that all these environmentally friendly materials must be used for as long as possible and disposed of in an eco-friendly manner for their greenness to count.
Note: Not all silicone products are created with the same level of quality and safety precautions. Cheaply made silicone can leach chemicals into your food—only high-quality silicone products from trusted and eco-certified or FDA-approved manufacturers.
Is silicone better than plastic? Admittedly, silicone is a more eco-friendly alternative to plastic, but it's not a perfect alternative. It's not curbside recyclable; its production process uses fossil fuels and doesn't biodegrade. It may leach siloxanes at temperatures above 300 °F.
However, you can recycle silicone products at specialized centers or reuse them at home. Silicone is highly durable, and its major raw material is sand. It's also preferable to plastic if you are concerned about toxins.
Is silicone eco-friendly? If you had to choose between plastic and silicone, we would recommend you use silicone. Look at the alternatives available to you and decide which one best helps you get closer to your zero-waste lifestyle goals.
Jamrógiewicz, M., Szymkowska, K., & Krenczkowska, D. (2016). Direct Human Contact with Siloxanes (Silicones) – Safety or Risk Part 1. Characteristics of Siloxanes (Silicones). Frontiers in Pharmacology. https://doi.org/10.3389/fphar.2016.00132
Fromme H, Witte M, Fembacher L, Gruber L, Hagl T, Smolic S, Fiedler D, Sysoltseva M, Schober W. Siloxane in baking moulds, emission to indoor air and migration to food during baking with an electric oven. Environ Int. 2019 May;126:145-152. doi: 10.1016/j.envint.2019.01.081. Epub 2019 Feb 21. PMID: 30798195.
Onnekink, C., Kappel, R.M., Boelens, W.C. et al. Low molecular weight silicones induce cell death in cultured cells. Sci Rep 10, 9558 (2020). https://doi.org/10.1038/s41598-020-66666-7
Grand View Research. Silicone Market Size, Share & Trends Analysis Report 2021 - 2028.
Grand View Research. Silicone Market Size, Share & Trends Analysis Report 2021 - 2028.
U.S. Food and Drug Administration. Indirect Food Additives: Polymers.
Jen’s a passionate environmentalist and sustainability expert. With a science degree from Babcock University Jen loves applying her research skills to craft editorial that connects with our global changemaker and readership audiences centered around topics including zero waste, sustainability, climate change, and biodiversity.
Elsewhere Jen’s interests include the role that future technology and data have in helping us solve some of the planet’s biggest challenges.