Silicone seems to be used in more and more products over time. At home, I have a silicone oven mitt, silicone bakeware, (partly) silicone tongs, and a silicone bowl-scraper.

It seems like a very inert substance, and I haven't seen any deterioration of the above items in the time I've owned them. However, very little lasts forever, and I've been wondering what happens to silicone when it starts to break down, especially when it's in contact with food.

Does it start to release potentially-toxic chemicals like plastic does when it breaks down?

Also, are there any particularly nasty chemicals used or released in its manufacture?

In case it helps: I had one re-usable container lid that may have been lined with silicone, and it seemed to break down after about 4 years of regular use. It became weak (started to get small tears along the edge) and sticky to touch. I'm not sure it was silicone, but it may have been.

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    Seems like a reasonable question, but it's not immediately obvious that it's about sustainability. Can I suggest emphasising that side of the question rather than the food safety angle?
    – Flyto
    Commented Apr 8, 2014 at 7:54
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    @Flyto, if it's not safe, or there are toxic byproducts, then it's not particularly sustainable in my view. Understanding this is probably the first step in looking at other aspects of the lifecycle of the material, such as whether it can be recycled, whether any particularly toxic ingredients or byproducts can be safely contained and neutralised. Commented Apr 8, 2014 at 21:07

2 Answers 2


http://globalsilicones.org ----- /sustainability/ and /silicones-chemistry/

'Alot has to do with type of silicone. All silicones are sensitive to uv light and will break down eventually. Some will leach oil over time and some will become brittle. My suggestion is to find out the type of silicone and the manufacturer and check the specs. I have silicone molds that are 17 years old and still going strong, the secret is to keep them in an air tight bag in total darkness and at room temperature' - minieffects @http://www.therpf.com/f9/how-long-would-silicone-last-22046/

So I did a little bit of research, using the links above, and basically silicones will not last forever, but all respond differently. The first two links are very positive on silicone, they view silicone as a way to extend duration and thus sustainability. Maybe someone who knows a bit more chemistry than me can chime in, but the chemical chains they are talking about seem to just be silicon and oxygen, which doesn't seems to be fairly stable to me. What are the byproducts in the laboratory and are they sustainable? That requires more research. Also, some people have silicon allergies.

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    This doesn't seem to answer the question at all, it's anecdata on the related "how long does silicone last" question. Can you please at least try to answer?
    – Móż
    Commented Aug 27, 2014 at 1:36

Silicon itself is not biodegradable and is tolerant to heat and UV exposure. In polymers, such as the manufacturing of utensils, tableware and kitchen appliances that are exposed to heat (think water heaters), the silicon is usually bound with other compounds.

The most significant danger from all polymers comes from combustion. The gases that are released will almost always contain compounds which are inert and bioacumulative. With respect to silicon, this will create deposits in the soft tissue around the neck and in the lungs from inhaling, even from brief exposure. It will lead to increased levels of potassium, an inflammatory process in the lymph nodes and tissues surrounding the neck and lung, it will impede lymph circulation and cause inflammation and calcification of the neck bones and the rib cartilage. Given that it will trigger an immune responses, when certain conditions are met, it will cascade to autoimmune diseases and neurological disorders first, early onset of rheumatic disorders later.

Generally speaking, accidental exposure to silicon fumes or ingestion of silicon would trigger a number of pathological processes and collection of, seemingly unrelated, medical conditions. One could say, with confidence, that it would be impossible for a healthcare professional to correlate these back to silicon, unless the amounts of silicon introduced would be acute, causing an obvious lung or skin reaction.

I believe it would only be acceptable to use silicon when, under no possible circumstances, it can come in contact with heat sources or food.

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    Thanks! Do you have some references for any of this information? I'd be interested in learning more :-) Commented Aug 30, 2014 at 21:35

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