When I first discovered silicone cookware, I thought it was too good to be true. I was baking a lot at the time and it pained me to use all those disposable cupcake cases and reams and reams of baking parchment. There was no way I was going to use toxic non-stick aluminum bakeware, and I hadn’t yet acquired any cast iron bakeware. Silicone muffin pans and cake pans seemed like a dream, but even now I’m still not convinced of their safety.
Since I’m not totally convinced of the safety of silicone cookware, I recommend purchasing these kitchen products instead:
Corning Ware: Another 5-leaf contender, Corning Ware is easy to clean, non-reactive to acidic foods, and can be used for cooking, serving, and storing food (View Prices on Amazon). Read our full review here.
De Buyer Carbon Steel Frying Pan: Finally, another 5-leaf product to top off the list, this carbon steel frying pan offers excellent heat distribution for easy grilling, searing, and browning of foods on the stovetop (including induction), camping stove, barbecue, or in the oven (View Price on Walmart). Read our full review here.
The benefits of silicone cookware
Silicone cookware seems like a great alternative to non-stick muffin pans and cake tins. And, unlike paper cupcake and muffin wrappers, silicone can be reused time and again. It is excellent for oil-free or low-fat cooking as it is non-stick and easy to clean, meaning you don’t have to grease the cookware before use. High-quality, food-grade silicone cookware is said not to affect the flavor of food, or react with food or drinks, and manufacturers claim that it doesn’t release any odors or toxic fumes during cooking.
Silicone cookware is also fun and easy for kids to use. It typically comes in bright colors, different shapes, and is easier to handle than fiddly paper or heavier metal bakeware. And, if you move house a lot, silicone bakeware is a heck of a lot easier than cast iron and ceramic bakeware to transport.
If you haven’t used silicone cookware before, though, it might seem rather strange and you’d be right to be wary of whether it’s actually safe and non-toxic.
What is silicone cookware?
Silicone is a synthetic ‘rubber’ that contains bonded silicon and oxygen and, in some cases, carbon. While these are natural elements and bonded silicon is abundant in sand and rock, silicone bakeware can contain all manner of other materials aside from oxygen, silicon, and carbon.
In general, silicone bakeware is heat-resistant, freezer safe, and oven safe, but only up to 428 degrees Fahrenheit or 220 Celsius. It shouldn’t be put in the dishwasher, however, and as it doesn’t biodegrade and cannot currently be recycled, it’s not exactly eco-friendly.
Silicone cookware also needs to be dried well before being stored, or it may degrade and develop discoloration and tackiness. I’ve had this happen to a couple of silicone cake ‘pans’, so I learned my lesson and store them more carefully. So carefully, in fact, that I rarely ever use them and should probably take them to the thrift store.
Why did I stop using silicone bakeware? Well, in large part because I began to acquire cast iron and ceramic cookware that served much the same purpose and performed better. And, if I’m honest, because that ‘tacky’ feeling gave me pause.
You see, while manufacturers rush to claim that silicone is a great non-toxic cookware option, there’s not actually that much research on the safety of these products.
Is silicone cookware safe?
There’s very little to suggest that silicone cookware is unsafe, but there’s also not much to confirm its safety either. What’s more, there are huge variations in the quality of silicone cookware, with cheap, low quality alternatives full of fillers and binders most frequently cited in concerns over odors and poor performance.
To test if your silicone bakeware is pure, give it a twist. If you see lots of white streaks, this suggests that there are large amounts of fillers in the silicone, which means it may not be suitable for use in cooking or baking.
When buying silicone kitchenware, check that it is 100% pure food grade silicone. This is the stuff that Canada’s health agency, Health Canada, maintains does not react with food or beverages or produce any hazardous fumes, and is safe to use up to recommended temperatures.
The U.S. Food and Drug Administration (FDA) determined in 1979 that silicon dioxides (the basic elements in silicone cookware) were generally recognized as safe (GRAS) to use as food-grade materials. The first silicone cookware (spatulas) were sold sometime in the 1980s, but the FDA hasn’t conducted any follow-up safety studies on silicone cookware.
Food-grade silicone cookware is typically coated in food-approved compounds or agents that help release food after cooking. There’s debate as to whether these coatings end up leaching into food, which isn’t helped by studies that use hyperbolic language and test conditions that don’t match real life use, as discussed in this paper.
What the research says about silicone moulds
In one study, very limited migration of these compounds was noted from silicone baking sheets or from the silicone nipples of infant bottles (R). This study did not actually heat the silicone bakeware in an oven, though, which undermines the usefulness of the research for those intending to cook with silicone products.
However, one study, published by the Swiss Federal Office of Public Health in 2005 looked at whether chemical substances were released from silicone baking moulds when they were heated to 200-220 degrees Celsius (the recommended limit for these products). They also tested the products up to temperatures of 280 degrees Celsius.
Up to 100 degrees Celsius, the samples showed low migration of chemicals from the moulds. This migration increased rapidly after moulds reached 150 degrees, however, with the samples reaching the exposure limit of 10 mg/dm2 prescribed by the Resolution of the Council of Europe in most cases. At higher temperatures, such as those typically used to bake a cake, migration increased even further. At 175 degrees, all samples showed high migration values (between 25.5 mg/dm2 and 49.2 mg/dm2).
In some cases, the levels of leaching chemicals dropped upon the third round of testing for a product. This suggests that manufacturers may not be properly ‘curing’ their silicone bakeware before sale and that it makes sense for consumers to heat any new silicone bakeware to 220 degrees without food for a couple of hours. Once it cools, wash the moulds thoroughly in warm, soapy water, rinse, and dry.
In another study, researchers found that non-tempered moulds with a high level of volatile organic compounds (1.1%) had considerably higher migration of siloxanes than the equivalent tempered moulds (R). Tempering is a process used to make silicone moulds stronger, harder, and more elastic.
Silicone in summary
Given that there is so little safety data on the use of silicone bakeware, and the availability of other types of cookware that are non-toxic, eco-friendly, and safe, I’d err towards ditching the silicone. That said, if you make jellies, chocolates, ice cubes, or popsicles, silicone moulds can be fun and likely pose little risk of leaching siloxanes into food. You might also want to use silicone moulds to make candles or soaps.
Basically, as long as you’re not putting silicone in the oven (or the dishwasher), you’re probably fine to use these products. Just remember to ‘cure’ the silicone moulds in the oven first and clean them thoroughly before using them for any culinary tasks.
As for silicone utensils, I’d suggest only using silicone spatulas, like this set from Lavador (View Price on Amazon), for working with cool foods, such as dips and batters. For hot foods, metal, wood, or bamboo spoons, spatulas, and other utensils are best.