Is Silicone a Safe Alternative to Single-Use Plastics?

stack of plastic bags next to one reusable bag

Richard Drury / Getty Images 

The folks at Life Without Plastic argue that these stretchy, rubbery bags are not as green as they seem.

If you spend any time perusing zero waste lifestyle blogs and social media feeds, you've likely seen silicone bags suggested as an alternative to disposable Ziplocs and plastic food storage containers. They're becoming quite popular, perhaps due to how photogenic they are, available in an array of colors and just transparent enough to reveal what's inside.

At first glance they're an ideal solution, offering all the benefits that plastic bags do – lightweight, flexible, stretchy, washable, waterproof. Some advocates argue silicone is more like rubber than plastic and that because it's derived from sand, it's a natural product.

The Pushback Against Silicone

The experts at Life Without Plastic disagree. Silicone, they explain, is "something of a hybrid between a synthetic rubber and a synthetic plastic polymer," which means it's still a plastic, no matter how it's spun. While it does contain silica, which is derived from sand, it also contains synthetic and chemical additives that come from fossil fuels.

An article on the Life Without Plastic website (excerpted from their excellent book) explains that silicone is widely accepted as safe by organizations such as Health Canada and the U.S. Food and Drug Administration, but there haven't really been many in-depth or subsequent studies into its long-term effects. LWP's founders have done their own research and have found reasons to indicate that "we should begin to be cautious about silicone."

They cite studies showing that silicones are not completely inert, that they do leach synthetic chemicals at low levels, particularly if the food they contain is high in fat; and that siloxanes (the backbone chemical structure of silicones) are endocrine and fertility disruptors, as well as potentially carcinogenic.

"One study tested the release of siloxanes from silicone nipples and bakeware into milk, baby formula and a simulant solution of alcohol and water. Nothing was released into the milk or formula after six hours, but after 72 hours in the alcohol solution several siloxanes were detected."

Silicone also has a very low recyclability rate. It is usually turned into industrial lubricant oil when disposed of.

Be Cautious About Silicone Use

If we're truly striving for zero waste, plastic-free living, then we should use alternatives to silicone bags – and plenty of these exist. Glass jars, stainless steel containers, and cloth bags can all do the job, without any of the associated production, use, and disposal concerns that accompany silicones.

Silicones do play a useful role as seals or gaskets in many reusable containers, but these do not generally come into contact with the food and are a tolerable use of the product.