In this guide, we outline whether silicone might be more sustainable than plastic, and vice versa.
This guide compliments our separate guide about the sustainability of silicone, & some comparisons to plastic.
Summary – Is Silicone More Sustainable Than Plastic?
Breaking Down Which Might Be More Sustainable
There may not be a clear answer as to which material is more sustainable.
Overall, silicone might be slightly more sustainable than plastic in some ways, but it can also present some of the same sustainability issues as plastic in other ways
They also have some similarities – both are synthetic polymer materials that can have issues with breaking down compared to organic and natural materials, and both can have lower recycling rates than other materials
For some uses such as leak proof lids for food containers, a high quality food grade silicone might be the better material
The answer can be product and company specific too – not all companies make their silicones to the same standard, or in the same way with the same chemistry
Just as one example, a high quality food grade silicone that meets safety regulations, is recyclable, lasts many years, and is free of fillers and toxic chemicals (and that does not leach), is probably more sustainable than most regular plastics
But, it’s also hard to get a true gauge on silicone’s actual sustainability score as there aren’t any comprehensive life cycle assessments (that measure different sustainability indicators) done on it that we could find
Ultimately, each plastic and silicone product is going to present it’s own pros and cons in terms of sustainability depending on what it is made of, and other sustainability measures like how it’s made and how waste can be managed.
Plastic & Silicone vs Other Materials
There may be more sustainable materials than both of these materials.
For example, some materials that are recycled at high rates, or that biodegrade in the environment quickly and effectively, may be more sustainable.
Plastic vs Silicone: Comparison
Difference Between Plastic & Silicone
The main difference between plastic and silicone is:
… most plastics have a polymer backbone of hydrogen and carbon, [but] silicones have a backbone made of silicon and oxygen, and hydrocarbon side groups (lifewithoutplastic.com)
General Sustainability Of Each Material
From a sustainability perspective, the differences and similarities are:
– Sourcing Of Materials
Plastics are generally made from fossil fuel feedstock like petroleum or natural gas, and they are considered no-renewable.
There is debate over the scarcity of fossil fuels
Silicone is made with the abundant natural resource, silicon.
But, is also usually made with hydro carbon groups (methyl groups) from fossil fuels too.
– Break Down & Degradation
One of the problems with both materials is that they are synthetic polymer materials.
They don’t really break down like organic materials and natural materials do
Plastic might be worse though because it breaks down into micro plastic and nano plastic.
– Leaching Of Chemicals For Humans
Both materials can have leaching issues with fillers, additives and chemicals
But, food grade silicone might have less leaching issues than most plastics
Some food grade silicones even claim to have no harmful or toxic chemicals
One source says if you pinch silicone ‘pure silicone does not change color at all, so if any white shows through, there may be fillers in your product.’ (earthhero.com)
– Impact In The Environment
Plastic can have a range of potential negative effects in the environment.
Various sources say silicone compounds can be prevalent in the environment too (wikipedia.org via bettermeetsreality.com), but probably less than plastic, especially micro plastics
Neither material has high recycling rates.
Although some types of plastic, and some specific silicone brands, do get recycled.
Most silicone often can’t or wont be recycled through regular municipal recycling streams, and plastic often has it’s own issues with contamination and other recycling related challenges
Neither material is biodegradable or compostable
– Material Lifespan In Use
Various sources say high grade silicone usually lasts longer than regular plastics, and resists deterioration (clearandwell.com).
So, this averages out it’s environmental footprint somewhat more than plastic
If Not Silicone, Then What To Use?
Silicone may be a better option than plastic for specific uses in some instances, such as leak proof food container lids.
It helps if the silicone won’t leach and contains no bad or harmful chemicals
It’s also possible that as a re-usable material, silicone can come out on top of other materials if used enough times.
This may be especially true in the instance of single use or limited use materials, such as when using a re-suable silicone straw over a plastic disposable one
But, for other applications and products, alternative materials may be better.
Materials that come from natural and/or renewable resources (that aren’t synthetic and that don’t have additives or fillers), have a high recycling rate, and are biodegradable or compostable, may be more sustainable than silicone.
Having said this, alternative materials still have to have the practical traits for the end use, or they won’t be effective.
The Sustainability Of Silicone
Read more specifically about the sustainability of silicone in this guide.
The Sustainability Of Plastic
Read more specifically about the sustainability of plastic in this guide.
This guide also outlines some of the overall pros and cons of plastic.
Other Factors To Consider
– Just as there are different types of plastic, there are different types of silicone
Each different type of silicone can have a different sustainability footprint
– Using recycled silicone for new silicone products can change the sustainability footprint of silicone
– The waste management systems, facilities and technology in a given country or State make a difference to the sustainability not just of different materials, but different waste items and products (because of how different waste materials and items are processed among the different disposal options at different rates)
– How long a silicone product or item lasts, or how many times it can be used/re-used before being thrown out, impacts it’s sustainability footprint