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What is Silicone and is it Toxic?

by The Soft Landing in Food and Drink Storage, Non-toxic Home
October 29, 2014 118 comments
Silicone has become a household name in the fall-out of toxic plastics. It's been touted as inert and versatile. But just what is silicone and is it toxic? The Soft Landing team investigated its potential toxicity, so click to see what they found out! | www.thesoftlanding.com
What is Silicone and is it Toxic?

Silicone has quickly become a household name in the fall-out of toxic plastics. Its starring role begins right away as we introduce it to our babies from the day they're born. It's been touted as inert and versatile, but just what is silicone and is it toxic?

We decided to give it a thorough background check. In the end, our research leads us to believe that food grade silicone used outside the body for food contact is chemically inert, stable, won’t leach into food, or off-gas. And Health Canada confirms what we’ve found: silicone does not react with food or drinks or produce any hazardous fumes.

Now let's take a serious look at that background check…

In the fall-out of toxic plastics, silicone has been touted as inert and versatile, but is it really safe?Click To Tweet

What is Silicone Anyway?

Here's a simple breakdown, courtesy of Beth from My Plastic Free Life:

It is a man-made polymer, but instead of a carbon backbone like plastic, it has a backbone of silicon and oxygen. (Note that I'm using two different words here: silicone is the polymer and silicon, spelled without the “e” on the end, is an ingredient in silicone.) Silicon is an element found in silica, i.e., sand, one of the most common materials on earth. However, to make silicone, silicon is extracted from silica (it rarely exists by itself in nature) and passed through hydrocarbons to create a new polymer with an inorganic silicon-oxygen backbone and carbon-based side groups. What that means is that while the silicon might come from a relatively benign and plentiful resource like sand, the hydrocarbons in silicone come from fossil sources like petroleum and natural gas. So silicone is a kind of hybrid material.” (Plastic-Free: How I Kicked the Plastic Habit and How You Can Too, p. 277)

Safety and Recyclability of Silicone

In her article Spotlight on Silicone, Mindful Momma explains that silicone has a good track record of safety. As for recyclability, she says “Silicone does not decompose but it is recyclable – although probably not through your city-wide recycling program. You'll probably have to drive to a specialty recycling facility – but then again, silicone is very durable so you won't have to worry about disposal for a long time.”

One of our favorite consumer advocates, Debra Lynn Dadd, explains that silicone is not toxic to aquatic or soil organisms, it is not hazardous waste. So while it is not biodegradable, it can be recycled after a lifetime of use.

Silicone Safety in Dishes and Cookware

We do feel very comfortable recommending silicone dishes as a safe option that won’t leach harmful chemicals into foods. High quality silicone dishes (like these) are a great alternative to plastics containing known carcinogens or endocrine disruptors. Its use in baby bottle nipples stretches back over 30 years, standing head and shoulders above nitrosamine-tainted synthetic latex nipples that break down quickly under repeated exposure to heat, moisture and detergents.

Now silicone cookware, on the other hand, may just turn out to be be non-problematic. But based on some new research that discusses the potential of formaldehyde and other VOCs off-gassing when exposed to high heat in industrial situations, we've put together some safety tips for using silicone for baking, microwaving and sous vide cooking.

A Little More Background on Silicone

Stacey Feeley, co-founder of Silikids, gave us some great background on the benefits of food grade silicone:

  • Can handle temperature extremes, transferring easily from freezer to microwave
  • Flexible, durable and shatter resistant
  • Petroleum-free
  • Dishwasher safe
  • Odor and stain resistant
  • Hygienic and hypoallergenic with no open pores to harbor bacteria
  • Does not fade or scratch

Tips for Choosing and Using Silicone Dishes

  • Be sure to choose dishes made from 100% food grade silicone. Fillers can compromise the quality and durability of silicone.
  • Confirm that all colorants used are not BPA-based and that lead testing has been done, especially for brightly colored products.
  • Don’t be fooled by thermoplasticized rubber (TPR) dishes. They look and feel much the same, but TPR isn’t as durable and doesn’t tolerate high heat like silicone does. Products like these measuring cups made from TPR often have a rigid plastic skeleton and may warp when exposed to heat.
  • Be aware that phosphate-free dishwashing detergents may cause silicone dishes to end up with water spots or hold onto certain smells/tastes. It’s no big deal, just add some white vinegar or a non-toxic rinse aid like Ecover to your wash cycle.

There are times when durability and convenience win out, leaving my glass and stainless steel dishes in the cupboard. So given the choice between plastics made with carcinogenic and endocrine disrupting chemicals, I’d opt for silicone anytime.

P.S. Learn even more about why silicone is safer and more eco-friendly than plastic in our latest update!