When choosing materials for many products we frequently use, we’re often faced with a couple of options, but none are as common as silicone and plastic.
Aside from being accessible and economical, it’s hard to resist their shatterproof properties, especially when we’re talking about lunchboxes, kitchenware, and even medical devices.
But isn’t silicone plastic?
That’s a question we get asked a lot here at Sustainable Review, and we totally get where the confusion comes from.
Silicone and plastic have a few similar qualities that make it a bit hard to distinguish one from the other at first glance. They’re both versatile, lightweight, waterproof, and durable. But their similarities end there.
These two materials have distinct components that also influence their performance and environmental impact. That’s what we intend to investigate here so you can decide which, between silicone and plastic, is a better option for you.
Understanding What Silicone Is
Silicone is a non-toxic polymer made from combining silicon, carbon, hydrogen, and oxygen. Silicon is an element derived from silica (sand), which makes up 59% of the Earth’s crust and is widely used in creating portland cement, mortar, concrete, glass, and ceramics.
Plastic, on the other hand, is made from plants and fossil fuel-based components like natural gas or crude oil. Unlike silicone, making plastic does not require carbon and hydrogen.
As man-made materials, both silicone and plastic are appreciated for their malleability. This property allows them to be molded into different solid objects of various shapes and sizes.
In terms of resilience, though, silicone performs better than plastic. It doesn’t lose its integrity when exposed to weathering, ozone, and UV. That’s why it’s preferred for making kitchen utensils, caulks, heat-resistant seals, gaskets, electrical insulators, and a variety of medical devices.
Other than that, silicone also stacks up well against plastic for qualities like:
- Chemical Stability. Due to its chemical structure, silicone is stable even at high temperatures. It can be frozen or heated without ruining it and your freezer or oven.
- Low Toxicity. Silicone also doesn’t react with most chemicals, making it an ideal material for food and beverage applications. We’ll have further discussion about this later.
- Stain-Resistance. The non-stick nature of silicone’s surface makes it resistant to most stains, making its upkeep easier.
Is Silicone Sustainable?
Of course, while silicone does have its advantages, it has drawbacks as well and they’re mainly linked to its lifecycle’s overall impact on the environment.
Manufacturing silicone uses a lot of energy, contributing to carbon emissions. Yet, compared to plastic, silicone has a much lower cradle-to-grave carbon footprint.
Data from 2019 has shown that emissions from plastic production and conversion amounted to 1.6 billion tons of CO2eq. Across all lifecycle stages, plastics emit around 54.6 billion tons of CO2eq, or 3.3% of total global emissions.
In contrast, a 2012 study commissioned by the Global Silicones Council sought to prove silicone’s potential to contribute to decarbonization. It looked at the GHG emissions linked to the entire lifecycle of products made from silicone, siloxane, and silane. It covered 26 case studies, accounting for 59% of the silicone industry markets in Europe, North America, and Japan.
It turned out that as substitutes for products with similar applications, silicone products enable GHG emissions reductions of about 54 million tons of CO2. Those emission reductions are equivalent to the carbon footprint of 10 million homes in the regions covered by the study.
It was also found that the GHG emissions from silicone production and disposal are outweighed by their reductions by a factor of 9. That means, for each ton of CO2 emission, using silicones allows for 9x more savings.
Although this appears to be good news, it should not be disregarded that silicones are not biodegradable. So, when silicone products reach their end-of-use and are discarded, they persist in the environment for hundreds of years.
Why not just recycle them instead? Good question.
Silicone can be recycled, but it is challenging to do so. As a thermoset, it doesn’t melt easily, requiring high temperatures and complex setups but often with minimal yield. Unfortunately, there are only a handful of facilities with such capability, and they’re not widely available.
Taking all that into account, it’s safe to say that silicone is not as sustainable as some make it to be. Still, it’s a better alternative than plastic for its potential to abate GHG emissions–an area that needs further attention. Its longevity also provides a better environmental trade-off by reducing the need for frequent replacements.
Is Silicone Toxic?
Safety is always an area of concern when buying new silicone products.
A review of toxicology studies of silicone compounds by the National Center for Biotechnology Information (NCBI) revealed that they have exceedingly low levels of toxicity, making them safe for use on consumer products.
That is particularly true for food-grade silicone, which often undergoes a strict purification process to remove low molecular weight siloxanes, which are noted to be toxic and bioaccumulative. This ensures they are safe for direct food contact and can be used for medical applications.
In terms of cooking with silicone, the concern is often related to the potential of chemicals leaching into food. Several studies concluded that the migration of chemicals into food often stays below safety limits.
However, caution should be taken when using silicone products to prepare high-fat foods. It was observed that foods with larger portions of free available fats that were prepared in silicone molds absorbed more chemicals. These findings also suggest avoiding heating silicone cookware in temperatures above 200°C.
To further keep yourself safe when cooking with silicone, consider these tips:
- Always choose quality, food-grade silicone cookware, free from harmful fillers and additives.
- Thoroughly clean your silicone cookware before use to remove residues from their manufacturing.
- Stick with the recommended cooking temperature range to prevent chemical migration.
- Follow the care, usage, and storage guidelines set by the manufacturer.
- Regularly check silicone products for wear and tear and replace them as needed.
More Sustainable Alternatives to Silicone
We understand that it’s hard to resist reaching for that silicone lunchbox and kitchenware, knowing just how long you can use them.
If you’re genuinely striving for a sustainable lifestyle, however, know that there are better alternatives out there. They can do an equally good job as silicone but without the environmental impact linked to its production and disposal. These materials include:
- Glass
- Stainless steel
- Bamboo
- Natural rubber
- Cork
- Polylactic Acid (PLA)
- Hemp
- Organic cotton
- Beeswax wraps
All these materials are made from renewable resources and are produced using less energy and water. They are non-toxic, biodegradable, and recyclable, making them suitable for various applications, from kitchenware to skin care. Many of them are also durable enough to be used for years, preventing you from making frequent replacements.
Final Thoughts
We definitely agree that silicone is an excellent material, which is a way better option than plastic. It’s versatile, lightweight, waterproof, heat-resistant, and durable. It’s generally safe to use for food, beverage, and personal care applications. Its potential to reduce GHG emissions, which can help in decarbonization efforts, is also something to watch out for.
Yet, as we always advocate for sustainability, the environmental impact of silicone’s disposal and non-biodegradable nature remains a concern. For that reason, there should always be a balance between our needs and that of the planet.
Meaning, if you can’t give up on your silicone products just yet for more sustainable alternatives, make an effort to properly care for them. That way, you can extend their lifespan, which can help reduce waste in landfills and minimize the need for new products.
