It’s more than likely you’ve come across silicone. There’s quite possibly a silicone spatula, whisk or measuring spoon in your kitchen drawers.
But, do you know the difference between silicone and plastic?
Here’s what two experts have to say about silicone, including its safety, life span and how it differs from plastic.
What is silicone? And how does it differ from plastic?
Oliver Jones, a professor of chemistry at RMIT in Naarm/Melbourne, says while plastics and silicones are both polymers they have different chemistry.
“Polymer is a general term for any substance composed of repeating simple sub-units … to form long chains.”
Silicone, Professor Jones explains, “is a generic term for a range of man-made polymers made up of a silicon-oxygen-silicon chain”.
“Plastics are generally based on a carbon chain with various other atoms or molecules as side groups from the main backbone.”
At a more practical level, Nathan Kilah says the main difference between the silicone and plastics we tend to use in the kitchen is thermal stability.
A senior lecturer in chemistry at the University of Tasmania in Lutruwita, Dr Kilah says the “underlying silicon oxygen bonds give it a degree of stability that other plastics don't have, and that's why it's able to be used so effectively as cookware”.
He says a plastic spatula — as opposed to a silicone one — is more likely to melt or chip away.
Dr Kilah says the flexibility of silicone is also an asset, particularly with products such as muffin or cupcake trays.
Is silicone safe to use?
Professor Jones says silicone utensils and cookware are “safe to use for their intended use”.
“Silicone utensils — like all food contact materials — are extensively tested.”
There are also different grades of silicone, he explains, with some rated to higher temperatures.
Professor Jones says there are two main codes for food-grade silicone, the German food safety standard (LFGB) and the US Food and Drug Administration (FDA).
While the LFGB is considered a little stricter, both codes “aim to regulate silicone products to ensure that no harmful chemicals are released into your food, even under extreme temperatures”.
Dr Kilah recommends checking the manufacturer's advice for the individual product
“Silicone will be labelled as suitable for dishwasher, microwave, oven or freezer [and is] generally quite clearly labelled.”
The main thing is not to overheat it, he says, and to use products for their intended use.
Does silicone create microplastics?
Professor Jones says that silicone utensils and cookware “tend to be quite inert and don’t break down very easily”.
While these products “can wear down and break up over time” the “particles that may result will be bigger than microplastics”.
He adds he’s “yet [to] read a paper where they identified particles from food or the environment as silicone-based”.
“Possibly this is an area we could do with more science on, but I don’t think the risks are high, even if particles were generated, they would be inert, and any such particle you may ingest would likely pass straight out again.”
Dr Kilah says changes in the colour of silicone products or visible cracks and damage are a sign that your spatula, muffin tray or ladle is at the end of its life span.
After a long time or rough use “mechanical breakdown” can happen, but using silicone products conventionally shouldn’t cause smaller particles to form or shed.
