Is Silicone Safe To Cook With? The Truth
Silicone bakeware has become ubiquitous in kitchens thanks to its many benefits. From oven mitts to baking sheets, silicone’s flexibility and heat resistance seem ideal for baking.
But there’s one question that gives many home chefs pause: Is it really safe to put silicone in a hot oven?
While throwing a flimsy silicone spatula in a 450°F oven likely won’t end well, many silicone pans and molds claim to withstand high temperatures.
So can you safely bake your favorite lasagne in that shiny silicone pan? Will your silicone muffin trays withstand the heat of a convection oven?
Before you fill your oven with silicone goodies, let’s examine what exactly silicone is, where you find it in your kitchen, whether it can really survive oven temperatures, and if not, what alternatives you can turn to.
What is Silicone?
From baking pans to jar lids to iPhone cases, silicone has stealthily become one of the most ubiquitous man-made materials on the planet. But what exactly is silicone made of, and why does it have such handy properties?
In a nutshell, silicone consists of wiggly chains of silicon and oxygen atoms, kind of like strands of silicon spaghetti. These silicon and oxygen bonds are what give silicone its ability to withstand high temperatures. Attached to these strands are molecules called functional groups, the most widely used silicones contain methyl groups (CH3), which allows silicone to behave more as a liquid or gel (silicone lubricants, paints etc.). These functional groups make different silicones unique, and allow it to have diverse uses.
When many silicone chains join together (crosslink) they create a flexible, rubbery material aptly called silicone rubber. It’s like each chain is a strand in a spider web. This spider web can be molded into any shape, from muffin tins to pacifier nipples to medical implants.
So why is silicone suddenly everywhere? A few reasons give silicone its advantage:
- Withstands temperatures up to 300°C (or higher, depends on the amount of time spent at certain temperatures) – can take the heat in baking or autoclaves
- Chemically stable and inert – doesn’t react with much
- Repels water and oil – slick and non-stick
- Flexible and bendy – can pop food out of molds
- Durable – stands up to years of use
But is it genuinely resistant to the intense heat of an oven? Let’s investigate further…
A 2022 European Union Study Raises Some Big Concerns
On December 6, 2022, the European Consumer Organization (BEUC), a coalition of European consumer advocacy groups, released findings from 10 of its member organizations showing that silicone baking molds sold in Europe can release harmful chemicals during use.
The study tested 44 silicone baking molds purchased in Europe by having each product undergo three migration tests following the procedures used for plastics that come in contact with food.
The findings of the study include:
- 10 out of 44 samples (23%) released high levels of volatile compounds or showed increasing levels with repeated use, indicating they are unsuitable for repeated baking.
- 27 out of 44 samples (61%) received a moderate “yellow” rating, releasing moderate levels of volatile compounds or substances of concern, such as octamethylcyclotetrasiloxane (suspected reproductive toxicity).
- 7 out of 44 samples (16%) received a “green” rating with low chemical release, and no substances of concern detected.
- 36 out of 44 samples (82%) released cyclic siloxanes, including some classified as toxic. Other substances of concern like phthalates and benzophenone were detected.
According to the researchers, while no immediate health risks are identified, it’s unclear what the long-term effect of ingesting these compounds might be.
A considerable number of the silicone baking molds obtained from online marketplaces like AliExpress and Amazon showed some of the poorest test results, releasing high levels of the concerning chemicals.
This would indicate—perhaps unsurprisingly—that Chinese-made silicone baking molds are often not held to the same rigorous quality and safety standards as those manufactured in regions with stricter regulatory controls.
However, the published study doesn’t detail the methodology used, calling into question some of the findings.
Most notably, the researchers do not specify the temperatures used in the migration tests. It’s possible they used extremely high temperatures far outside the normal baking range, which would likely greatly accelerate chemical release. Using the recommended baking temperatures for each product would likely substantially reduce any potential risks.
Other Studies on Silicone Cookware
A 2005 study from the Swiss Federal Office of Public Health had researchers testing 7 different silicone molds commonly used for baking. They used several standard methods to evaluate the release of chemicals when exposed to temperatures up to 280°C, much higher than your average baking temperature. The tests showed that the molds held up pretty well below 150°C, but above that threshold they started releasing concerning levels of silicone-based chemicals.
The study also found that the molds lost significant amounts of weight when heated, especially during initial uses—indicating that the molds aren’t as stable at high temperatures as the manufacturers claim.
The scientists concluded that current test methods don’t provide the full picture of how these silicone baking molds behave when exposed to heat. But their results suggest the molds may not be as heat-resistant as we thought.
However—again, this study’s approach raises some concerns.
Regarding volatile release, they cut the moulds which penetrates and weakens the material which would definitely allow for higher release of volatiles (basically punctured and weakened the coating that prevents release of chemicals)
A 2019 study looked at whether chemicals called volatile methylsiloxanes (VMS) are released into the air or absorb into baked goods when using silicone baking molds.
Researchers tested 14 silicone and 3 metal baking molds purchased in Germany, Italy, and China. They baked cakes and measured VMS levels in the air during baking and in the baked cakes.
They found higher VMS levels in air when using some silicone molds, especially cheaper ones from China. VMS levels dropped after the first use of a mold.
In cakes, higher VMS levels were detected around the edges versus the center. Overall, the study found fairly low VMS levels in cakes compared to exposure from cosmetics.
The researchers conclude that silicone molds are safe for baking if directions are followed, especially pre-cleaning molds first and using recommended temperatures.
A 2009 study found that silicone baking molds that had not undergone tempering and contained high levels of volatile organic compounds (1.1%) released significantly more siloxanes than the same molds that had been properly tempered. Tempering is a process that makes silicone molds stronger, harder, and more elastic by exposing them to moderate heat over time.
Is Silicone Safe To Cook With?
Yes, silicone bakeware is generally considered safe to use for cooking and baking purposes.
However, aware consumers should still take a few reasonable precautions. It’s best to closely follow the manufacturer’s instructions, avoid overheating the silicone, and minimize use of old, worn products that may break down over time.
Opting for glass, ceramic or metal bakeware is an even safer choice.
While quality food-grade silicone should withstand normal baking temperatures, more research is still needed on the long-term stability and inertness of silicone when subjected to repeated high heat. Until those definitive studies are completed, prudent cooks should apply common sense measures for safe use of silicone in high temperatures.
Overall though, when basic guidelines are followed, silicone can be safely used for most home baking needs. However, based on the studies we looked at, we recommend avoiding silicone cookware made in China, instead opting for that made in the USA or Europe.
Safe Alternatives to Silicone Cookware
Despite its benefits, silicone cookware is non-recyclable and non-biodegradable. Additionally, it appears that low-quality silicone cookware can release harmful chemicals. If these are concerns for you, there are eco-friendly options available. Alternatives include cast iron, ceramic, glass, and stainless steel, each offering their own unique benefits.
Click here to read our guide on non-toxic cookware for lots of Better Goods approved alternatives.