Dear Recyclebank: Where does silicone fall on the eco-friendly spectrum? –Kim S.
Dear Kim: First, let’s make sure we are talking about silicone, and not silicon. Silicon (spelled without an “e” at the end) is the fourteenth element on the periodic table and one of the base materials that makes up silica, the most common substance on Earth. Elemental silicon is used to form the base of micro chips, and is also found in bricks, glass, and concrete as silica, and in enamels, pottery, and ceramics as silicate: A classification of minerals formed by mixing silicon, oxygen, and reactive metals. Silicones, on the other hand, are synthetic polymers made of silicon, oxygen, and other elements (usually carbon and hydrogen).
Silicones have many uses in a variety of industries and consumer products. They can be found in aerospace and construction adhesives, coatings, and sealants because they can withstand extreme temperatures and absorb stress. They are used in electronics as sealants because they are moisture, salt, and corrosion resistant. They’re used to house electronics like computers, fax machines, phones, and keyboards for the same reasons.
You may also be surprised to learn that silicones are found in aerosols like furniture polish and in personal care products like deodorants, make-ups, lotions and sunscreens. One household use of silicone you might be most familiar with is bathroom caulk. Silicone is ideal for this application because it is water resistant and antimicrobial. While you might think of silicone caulk as a one-time-use product, check out this how-to to learn how you can recycle this type of silicone from home!
The most pertinent household application of silicone is in bakeware.
Silicone bakeware has received a lot of attention lately because it is highly functional: It can go from the oven to fridge to freezer without any fuss. These products are even microwave and dishwasher safe! Silicone bakeware is non-stick, and in fact, experts recommend you skip greasing silicon baking dishes, as they will function better without the grease, and will make cleanup easier as well. Compared to their plastic counterparts, silicone spatulas are the obvious choice: They are friendly on non-stick surfaces, and can handle the high heat of a stovetop.
While there is nothing about silicone chemically that would prevent it from being recycled, curbside recycling programs rarely accept it, and it can be difficult to find a silicone recycler to accept post-consumer products. This is because many consumers confuse polyurethane with silicone.
One way to recycle silicone bakeware is through Terracycle’s Zero Waste Kitchen Box mail-out service. The service can be expensive for an individual, but manageable if you organize a collection with a group of friends. Alternatively, if you have damaged silicone bakeware that you can no longer use, cut it into smaller pieces to use as potholders, hotplates, or jar grips.
Where silicone falls on the eco-friendly spectrum is relative. While the base silicon comes from quartz, a plentiful resource, the hydrocarbons used to make silicone usually come from petroleum or natural gas. The methods for obtaining and processing these materials have well-established environmental criticisms. Silicone is arguably more environmentally friendly than plastic in kitchen applications, as plastic is not as hardy or long lasting as silicone is — and silicone is more inert that plastic, which means it has a lower chance of leaching chemicals into food when used for food storage. Using silicone in kitchenware can be a good option as long as you maintain it to ensure it has a long lifespan, and do your best to recycle it once you can no longer use it.