Is Silicone Toxic and Is It Silicone Bakeware Really Safe?

Is Silicone Toxic and Is It Silicone Bakeware Really Safe?

The following post is from Katie of Kitchen Stewardship:

Silicone Bakeware, Silicone Baking Sheets, Silicone Cupcake Liners, etc…

With holiday baking coming up and gift season to boot, I’ve been thinking again about the safety of silicone bakeware. Silicone pans, silicone baking mats, silicone cupcake liner, and silicone cooking utensils are not only a huge trend in the common culture but also touted as a way to “bake green” since you can avoid throwing away aluminum foil or parchment paper if you use and reuse silicone baking mats. They make great gifts since they’re generally both cute and affordable. But is silicone really a safe choice for your health?

I’ve been using the baking mats for years under the pretense that silicone is safe, especially compared to the hazards of aluminum and the many safety issues surrounding Teflon.

It seems that a few times a year, I’m asked to explain my rationale for choosing silicone bakeware, and since I can never remember the answer, it’s time to officially revisit that issue: Is silicone bakeware safe? Can it silicone leach into the food or does silicone offgas into the air?

What is the Composition of Silicone

Silicone is a synthetic (man-made) material created by bonding silicon with oxygen. I think I often type “silicon baking mats” but that’s wrong – silicone baking mats is the material in the bakeware. Silicon is right on the periodic table, a natural element that is in sand and makes up 28% of the earth’s crust. However, I don’t eat on the earth’s crust. “Is a natural substance” can’t be the end of one’s material safety research.

Does Silicone Interact with Food

Silicone is FDA approved as a food-safe substance. (Note: that sentence means very little since the FDA approves a whole bunch of things for human consumption that I don’t trust, like hydrogenated oils, for example.) Almost all the sources I’ve found state that silicone is inert, doesn’t react with food or liquids, and doesn’t offgas chemical fumes. Those that stated otherwise were usually single people in a forum or comments railing about silicone being toxic.

Sources that claim “inert” and seem very genuine include Dr. Weil, Scientific American, and the research at Green Living Tips. Sources that claim “silicone offgasses” include the husband of one of my own readers, a material science engineer, who “will not touch the stuff.”

However, there haven’t actually been studies testing silicone’s reactions with food under heat. The “nonreactive” claim is just based on the fact that silicon (the element) is “inert.” Again, let’s be serious: just because something in nature is fairly stable doesn’t mean I’ll necessarily cook and eat on it.

Note: there is a discrepancy between food-grade silicone and industrial grade silicone, just something to take note of when doing research on the safety of silicone in general.

Is Silicone Bakeware Safe
source: scubadive67

Concerns About the Dangers of Silicone Bakeware

With all of that said, here are some things to keep in mind:

  • Lower quality silicone coatings contain fillers that may be hazardous. Most sites say that if any white shows through when you twist your silicone bakeware, there are probably fillers. (Going to the kitchen to twist some silicone, excuse me a moment…)
  • The oils in silicone, which are very powerful and toxic, may “migrate” from the material, but I can’t find any real data.
  • Some sources offer concerns about bright colors and leaching.
  • Some (many?) have concerns about odors during use, but that may be related to the fillers, and not the silicone. I do notice an odor or smoking every so often, especially when oil hits the surface (like when roasting pumpkin seeds tossed in EVOO).
  • Many silicone baking mats are actually made of fiberglass covered on both sides with silicone, so unless you want to risk fiberglass in your food, don’t cut on the mats!
  • It’s reasonably new, so long-term studies haven’t been performed on cookware that has been exposed to high temperatures over very long periods.

I take three issues into account when making purchases for the kitchen: Is it safe for my family? Is it safe for the planet? Does it make the act of making food easier or tastier?

Is Silicone Bakeware safe?

Just because there aren’t many studies done on food safety and silicone that show that it is not safe most certainly doesn’t mean it is safe. All over the Internet, people are basically saying, “I can’t find anything dangerous about silicone, so I assume it’s a safe material.” That’s basically what I’ve said over the years, and now I’ve just contributed another article to the vastness of the Internet that says little to nothing about the safety of silicone. Drat.

The bottom line on safety is:

  • Check your manufacturer for other materials possible contaminating your silicone bakeware.
  • Treat it well – no cutting on those baking mats!
  • If you want to be very conservative, skip the silicone and stick with glass, cast iron, or stainless steel for cooking and baking and unbleached parchment paper if you need something flexible.

Can you Microwave Silicone?

According to the product manufacturers, silicone is safe for use in the microwave, oven, and freezer.

Yes, I do use it in the microwave and given the choice, would choose it over plastic any day.

Is Silicone Bakeware good for the environment?

Some sources say silicone can be recycled, which is great. It doesn’t take more energy to create than glass or mining metal for pots and pans, and it is not toxic to aquatic or soil organisms.

So for the earth, silicone bakeware is a fine choice compared to just about anything else out there, and better than Teflon, which contains chemicals that won’t break down at all.

Does Silicone Cooking Product Make Cooking Easier or Faster?

Other than when I get them all stained up, I love my baking mats. They’re awesome for homemade crackers and cookies especially. I also swear by my silicone “spoonula” for scrambling eggs in the pan and other stovetop cooking.

However, many people don’t like the way silicone pans, muffin cups, and loaf pans bake unevenly and don’t properly brown the food. I found the muffin tin to be a beast to clean, much worse than its metal counterpart. I gave mine away after one use and went back to paper liners. The “nonstick” claim leaves a lot to be desired on the three-dimensional products, but the mats are still my friend…unless I decide they might be toxic. Sigh.

Sources: 1, 2, 3, 4, 5, 6

Do you use silicone bakeware? Why or why not?

Katie Kimball has been “green” since 5th grade when she read 50 Things Kids Can Do to Save the Earth. She remains slightly disappointed that she didn’t actually save the whole thing back then, but now that she has 3 kiddos counting on her, she keeps plugging away hopefully. Katie blogs at Kitchen Stewardship about real food and natural living and is the author of Healthy Snacks to Go and other eBooks, available for Kindle.

This Post Has 54 Comments

  1. Thanks for an informative, balanced post. I like the idea of silicone, but geez, the smells it gives off when heated, and the way it’s a sponge for food odors make me wonder. Why can’t someone test what gasses actual, store-bought silicone items actually emit?

  2. This is the best discussion on the debate about the safety of silicone. thanks so much!

  3. I have a silicone coffee pour over funnel; I do use unbleached filters in the funnel; however, I and am wondering if it is truly “safe”.

  4. Bless your heart Katie for stickin’ to it in your efforts to save the earth. You remind me of my 3 year old granddaughter who would come in from outdoors carrying handsful of trash. I asked her why are you bringing in trash? and she said “I just want to save the world”. She had been out picking up trash in the apartment grounds.

  5. You should try the Silpat by Demarle. It is food grade silicone that is Kosher certified. No strange smell and very easy to clean. Just soap and hot water.

  6. Thanks for this article. Time will tell if the silicone is long-term safe with heat. Sadly. It would be nicer to know now before health damage.occurs. 😛
    I have a silicone muffin pan and steamer tray that came with my Microhearth microwave cookware and I still can’t decide if I’m brave enough to use it. I LOVE the pan though and it’s a nicely made product that I have been using for over a year to make everything you could imagine – in a microwave. I have written to the manufacturer to make sure the silicone is 100% with no fillers. I bet it is, since the company seems conscientious about food grade and safety.
    I really want to make muffins in my microwave…
    Is there any info about the safety of silicone cookware used in a microwave?? I’ve been looking and have not found anything as yet and I’m hoping that Microhearth has already eliminated any health concerns before they released their product since they are still in business after so many years (one would think they would have failed by now if their products were unsafe).
    Just another silicone safety question to add to your pile…

  7. Just purchased online silicon ice trays. When I open the package it was in, there was a chemical smell. When I put nose to the bottom if the ice tray (where various colors – pink, purple, yellow) of what I believe is the manufacture’s claim to be silicon (so that ice cubes can be popped out). Want to
    Know how safe this is?

    Product is distributed by Meridian Point Products, Somerset, NJ and is made in
    CHINA. UPC is 754814025215.
    Thank you.

  8. I read in the Bread Baker’s Apprentice that parchment paper is just coated with Silicone, so what’s the difference then.

  9. I have never used silicon bakeware & was just researching it because I wanted to buy a muffiin pan. After reading this, think I’ll jut buy muffin papers instead. Thanks!

  10. It might be helpful to also research the horrible dangers of using a microwave. Google microwave dangers. I was shocked the first time I saw it. What else besides silicone could I use to strain tea using a wide mouth canning jar funnel? Love all the comments and think I will stay away from silicone.

  11. I just can’t bake in silicone–but I do buy nice ones cheap at yard sales (because not many do bake with them and they don’t know what else to use them for) Silicone bakeware is FANTASTIC for freezing and making healthy “candy” with coconut oil. I use the silicone mini bread pans for freezing broth. Tovolo makes a nice twisty silicone popsicle mold. I love the gigantic ice cube trays for freezing leftovers or manageable amounts of beans or veggies to add to soups, leftovers, babyhood, etc. I roast red peppers by cutting off both ends and flattening the rest into a long rectangle. After they are peeled and cooled I roll them up into layers that look like big rosettes. When frozen put in zip freezer bag. Easy to slice when frozen and add to anything.

  12. I remember for a chemistry lab experiment, we used silicone bakeware and exposed them under cake-baking temperatures, then under extreme heat. They are as proclaimed; the food was cooked almost perfectly, with minimal chemical residue (Yes there is residue but at trace amounts).

    This partially discouraged me to use silicon products, so I guess I’ll stick to non-stick metal pans.

  13. Thank you for voicing what was in my head. 😀 I stopped using a microwave about 2 years ago and couldn’t be happier (and healthier). 😀 And I too was thinking about silicone, and have decided to pass on this material. Thanks for the helpful

  14. Nice article but too long. These days no one has time to read long one. I came to do a quick search not to read novels.

  15. Your granddaughter and kids like her are a big part of why I have unshakable faith in the future of my species regardless of how badly we screw up 🙂

  16. Thanks for this informative article. We don’t use Teflon anymore because we have birds, and I was buying a mini muffin pan and wanted to know if silicone would be safe to use around them. I’m thinking not. Thank you!

  17. cheese cloth

  18. That’s what I use my silicone bakeware for too!

  19. I thought of that, but the muffin papers could be toxic too. Paper is often bleached and the muffin papers are then dyed. I wouldn’t use them.

  20. Thanks , what are your views about cookware with a 3 ply base incapsulating aluminium? Thank you

  21. Hi, i am wondering what your opinion is on using a pressure cooker that has a silicone gasket? The high heat and pressure used in this method of cooking has me concerned about the possibility of chemicals leaching from the gasket . Thanks.

  22. anyone know anything about the Roshco company and their reputation for silicone bakeware? Made a Blueberry coffee cake yesterday in their pan and the taste was a little “chemical like”

  23. My silicone bakeware does NOT smell. If yours does, please don’t use it. Return it to the manufacturer. Don’t assume all silicone is the same. There are many grades.

  24. Also many products say ‘silicone’ or come up under search for silicone, but when you read the fine print it is either teflon or contains Teflon. Made that mistake and had major fumes, even though I spent a fair amount of time researching, and the item I purchased was not cheap compared with other products.

  25. You could put some muslin or thin cotton over your funnel. Or maybe strain your tea with an old fashioned metal tea strainer! If you can’t find one, how about making your tea in a cafetiere? Such as the ones that coffee is made in. Failing that, you could always invest in a gold one cup coffee filter. The sort that fits over a cup/mug and you just fill with hot water. Obviously, it will be a bit more expensive than normal plastic ones, but it will last for years. I’ve been using the same one ( purchased from Whittards ) every day for over 15 years.

  26. Hi. My husband went out and bought me 12 different silicone baking pieces: I threw away the muffin one and the ice cube…not worth the cleaning mess. The ice cube ones pieces rarely sent a w h o l e cube out, rather in pieces. But I l o v e the bunt pan and loaf shapes:)! True, it all has to be supported – but a cookie sheet does the trick:) And I have n e v e r used butter or spray on any of my pieces, and food comes out v e r y well!

  27. Something unusual to consider about a chemical odor or taste transfer… I bought (intrepidly) a silicone donut pan. I washed it by hand and used it right away. No odors or taste in the food. Then I put in dishwasher (said it could). Next time the donuts tasted of chemicals. When I went to smell the pan, it smelled like my dishwashing liquid, which, despite my desire for natural things, is your standard chemical fare. After soaking and washing several times in a natural enzyme cleaner, I finally got the smell out and donuts taste good again. I still don’t know that it’s safe of course, but I certainly don’t use that dw liquid on it anymore.

  28. If it gives off a smell, it should send up a red flag! Maybe someone that has pet birds could post about how their birds have fared while they baked something in silicone pans. I’ve read about birds dying while ovens were self cleaning and where Teflon pans burned.

    This article and comments posted confirmed what I’d been thinking about these pans and needless to say, I won’t be buying any. I will limit the use of the silicone spatulas I own to “scraping” the sides of my food processor to get all the food off; for stirring cold or room temperature food and for occasional flipping of food cooking on pans the stove.

  29. Agreed. For twenty-8 years my microwave has been used about 6 times to heat up a heating pad. One of the basic things m-waves do is change the molecular make up of the food so when you try to digest it, your body doesn’t recognize it, nor does it know how to get rid of it. So mucus forms around it to protect the rest of the body from the unrecognizable foreign substance. Then years later when we develop, cysts, tumors, plaque which are all nothing more than hardened mucus, clogging our lymphatic/immune systems. We wonder how we got sick. People have to wake up and realize man-made food or food processing is NOT better than what Nature creates and that we WILL pay a price for the convenience we enjoy now IF we continue to consume or expose our bodies to these man made creations.

  30. I would like to know what can be used as an alternative to aluminum foil. I don’t go near anything aluminum that might touch and leave a trace of it in my food. I have been using tops of stainless steel sauce pans and parchment paper but doing that doesn’t work for everything.

  31. Wikipedia says: At temperatures of approximately 149 °C (300 °F) in oxygen-containing environments, the polydimethylsiloxane (PDMS) in silicone begin to generate formaldehyde,[19][20] and by 200 °C (392 °F) silicones begin exponential increases of formaldehyde production, based on the thermal stability of function group used (with thermal stability as phenyl > vinyl > methyl > trifluoropropyl).

  32. Hi,
    In my opinion those silicon trays cannot be safe. One disintegrated while baking something in it. Another one emits A LOT of smoke when in the oven.
    Use the good old glass or stainless steel.
    Wishing lots of health from Israel

  33. “One of the basic things m-waves do is change the molecular make up of the food”

    Yes, this is called dielectric heating. Take a science class for crying out loud. You know what else changes the molecular make up of food? Macrowaves, aka “thermal energy” aka “baking.”

  34. Microwaves denature food, breaking the molecular bond ironically, causing many toxic substances to be produced. This is hardly the same process as traditional methods of heating, You take the science class, dummy. and while you’re at it, look up the word “mutagenic”. Microwaved food, particularly oils, meats, milk and eggs are completely destroyed and rendered mutagenic by heating them with radio waves. ingesting mutagenic substances changes your DNA, which genetic mutation is them passed to subsequent generations, as well as sickening the person who ingested it directly.

  35. If this is three ply ceramic, toss them after five or so uses, they’re done.

  36. “Microwaves denature food, breaking the molecular bond ionically, causing many toxic substances to be produced. This is hardly the same process as traditional methods of heating, so you take the science class. And while you’re at it, look up the word “mutagenic”. Microwaved food, particularly oils, meats, milk and eggs are completely destroyed and rendered mutagenic by heating them with radio waves. The food becomes toxic, losing most of its nutritive qualities, becomes highly acidic and when entering the body creates massive amounts of oxidants, highly corrosive substances. Ingesting mutagenic substances changes your DNA, which genetic mutation is then passed on to subsequent generations – as well as sickening the person who ingested it directly.”

    That is complete and utter bullcrap. I’m sorry, but I’m not going to argue with your “Google Science.” Take a science class for God’s sake. The only “sheeple” I see here are the ignorant and scientifically challenged fear mongers like yourself.

  37. Leslie – Please cite the source of your information that microwaves “denature” food. You know when an egg white changes from clear to white, the proteins are changing.

  38. Apparently parchment paper is coated with silicone or other nonstick stuff. Great!

  39. I wouldn’t use it. Period.

  40. Can anyone recommend a non-toxic option to replace parchment paper? I want to make homemade, gluten-free crackers and the recipes I’ve found call for parchment paper. Was hoping to swap out parchment paper with the silicone baking mat, now I’m concerned about their safety. The recipes range from 200 to 325 degrees F … would the silicone mat be safe (no leaching or off-gasing) at the lower temp (200F)?

  41. Only an idiot is afraid of cooking in a microwave.

  42. Polydimethylsiloxane contains no carbon so it can’t breakdown into formaldehyde (CH=O-H) . The Wiki entry for silicone rubber doesn’t say what you quote. It mentions formaldehyde as an aside as it is the breakdown product of a carbon based polymer with a similar looking structure to silicone rubber.

  43. Cysts, tumours and plaque are hardened mucous? What utter twaddle! The same goes for the microwave misinformation. Microwaves aren’t ionising radiation so they don’t ionise food : they haven’t got photons of the energy to do that. Plain old heat (radiative heat is infra red and that has higher energy photons than a microwave )will denature proteins that’s why you don’t stick your hand in a boiling pan and the reason why your egg will cook in the same pan!

  44. I don’t know about the mucous twaddle, but you may be interested in talking to your doctor about using a microwave to heat a babies bottle! The reaction I have heard is a very resounding NO. Not because of possible higher than advised temperature, but because of some kind of a atomic change in the milk. Also you may be interested in the deaths caused by heating blood for a transfusion with a microwave.

  45. I use silicone in other areas of my life and find against my skin as soon as it reaches body temperature I am getting a hot blistering feeling and raw broken skin within minutes. I had a look into whether silicone can cause allergy but although as an element silicon allergy is extremely rare, many silicone products are mixed with latex and it’s likely I have a mild intolerance of latex. I can’t call it a full blown allergy as its not anaphylaxis. It’s not possible to know what’s in your silicone product but it’s more of a problem than the silicon elements I’d say.

    However, nothing is safe, even breathing oxygen which we require causes cellular damage over time. Probably silicone bakeware is better than aluminium, Teflon or scorched paper. Most of it does smell of latex though. Are there latex free silicone cooking utensils I wonder?

  46. I’ve used it successfully for baking for eons. I’ve never noticed a flavor nor a smell. Sometimes, I think if we expect odors, we imagine them. My biggest question that I’ve always been deadly afraid to ask is what about using it for lining a roasting pan. Have any of you drizzled your veggies with olive oil? Or simply roasted a meat on it? I’d LOVE to be able to do that but since I don’t know I’ve never tried.

  47. There are also excellent fine mesh strainers (one came in my Whittard tea pot). Again, depending on the type of plastic mesh, how and where made, these might or might not serve you. Mine had no smell whatsoever when I poured hot water through it to eliminate any manufacturing residues. That’s my test for all plastics: pour hot water over them, and if they smell, they become vessels for potted plants.

  48. Thank you, thank you, THANK YOU for pointing out the non-alarmist facts about cooking. While I don’t want to stick my head (or other body parts) inside a microwave chamber, facts show it is safe for cooking. It’s only a matter of taste and texture…

  49. Get a new doctor. If he didn’t explain that the worry isn’t the milk/formula being heated, it’s the plastic and what it can release, he’s not worth the (lame training) diploma he has on his wall.

  50. I agree that our minds can play tricks on us. You likely have purchased higher grade silicone, made without cheap plasticizers which break down and off-gas during cooking. Since you’ve had it for “eons”, I’d venture a guess that it was USA-made (or quality equivalent). Stuff from China is seldom what it claims to be, and even then, “natural” things are sprayed and packaged with rodent repellant so they aren’t destroyed in warehouses and on board ships for weeks. Everybody wants to claim “natural” and “organic” are great, but don’t consider whether they might be mislabeled. Remember, the Chinese are the people who ground up melamine to pretend it was milk for their own people.

  51. You may wish to look to products manufactured for laboratories, or that are made in the USA or clear the Switzerland quality standards. Trust your nose, and your skin, if in doubt. Trust some older products vs. newer ones which might be made on the cheap, i.e. with latex or other plasticizers. Visit resale shops for “oldies but goodies”, and they would have “Made in USA” molded right into them.

  52. Of course they would be safe at lower temps. If you start going below freezing with some plasticizer additives to silicone, upon bringing back to room temp they can off-gas and possibly even smell.

  53. And we all know Wikipedia to be totally reliable…. not!

  54. non-stick metal ? like teflon ? Oh my god ! Have you done any researches on non-stick toxicity because those are available by the thousand online. Reading at everyone else’ comments, I’m wondering if the silicone you use in your lab experiment were colorful or just plain ? Perhaps the colors are the problem !

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