Making Silicone Safer And More Recyclable For The Food Processing Industry

Silicone is probably one of the most taken-for-granted materials on the planet today. It is hard to imagine the world without silicone, and this is increasingly true in the food processing industry.

There are many different grades of FDA-approved cords, gaskets tubes, profiles and strips all made out of silicone — and which are necessary for fully functioning food production lines.

Silicone has many advantages over other similar purpose materials and it is increasingly used in food processing, where it is edging out previously dominant types of rubber extrusions. Yet for many people, it isn't entirely clear what needs doing with the silicone once we've had our use out of it. 

Too much of a good thing?

As it stands, silicone is simply not recycled enough.  There are actually quite a number of reasons for this and some of them are pretty complicated. But the biggest reason is that we do not have the infrastructure to cheaply and easily recycle silicone. And for this reason, very little of it is repurposed. 

Silicone is hard to recycle because it is difficult to break down. In a way, this resistance to biodegradability is one of silicone's great strengths. Silicone is not like other common materials such as plastic. It does not react with chemicals in the earth. It does not leach out into the soil or water or break up into microplastics. In a landfill, it just kind of sits around doing nothing for 500 years before it naturally expires.

This I believe is the reason why there is no way to recycle silicone cheaply and effectively. There's just no urgency, for example, like there is in the battle with climate change or plastic. Businesses think they have the luxury of 500 years. But this is not the right mentality to have. This goes for all Industries that use silicone extrusions, not just the food processing industry.

The current state of silicone recycling

Just because silicone is hard to recycle it doesn't mean that there aren't some efforts to do so — but these efforts frankly are few and far between. Not only is recycling expensive and tricky to do, but there is also a lack of resources available. And even a lack of market stimulus. After all, if no one is looking to recycle the stuff in the first place, it'll be kind of hard for a recycling business to hit the ground running.

Presently, the best method we have to break down silicone includes cutting it into small pieces and then putting it in a salty solution at extremely high temperatures. Only in this inhospitable environment will chemical reactions slowly start to unravel silicone’s molecular bonds.

There are also ways to repurpose silicone — which there is also a lack of enthusiasm for. Such methods of repurposing can be as simple as cutting up silicone and turning it into rubber mats. 

And that's pretty much about it. Sure there’s no urgency to the silicone question, but do we really want to leave ever-growing amounts of it in the Earth for future generations to grapple with? As we move forward in time, large amounts of silicone in landfill sites could end up being hard to access and in a position to start doing environmental damage. True, half a millennium is almost an unfathomably long time away but if we can do something about it, shouldn't we?

The need to recycle silicone is there, we just need to put the right infrastructure in place to encourage it. Our pan-industrial attitudes need to change. And if we implement a wide strategy of networking and of making the process of recycling cheaper, easier and more accessible, then I am confident we can turn things around quite quickly.

Silicone and safety first

Silicone usage in the food processing industry is increasing all the time. Key reasons for its popularity include cost-effectiveness and practicality. And FDA grade silicone has long been known to be safe to be in contact with food.

But there are some people who aren't wholly convinced. There are fears of so-called “siloxanes” —  thought to be trace elements of silicone that can make their way into the body by leaching into food and especially food that is high in fat content. It's worth bearing in mind that these concerns are only really apparent in food packaging itself. Not in food production.

It's good that people should be concerned and it's better to be safe than sorry. In case you were wondering, the type of silicone causing the most anxiety at the moment is a so-called cyclic type of siloxane.  This type has no odour or colour and is sometimes even added as an active ingredient in face and moisturising cream. 

There isn't much evidence that these types of silicone can harm human health but there are concerns that re-exposure over and over could pass what's called the “1000 Dolton limit”. In which, hypothetically, traces of silicone could make it inside of the human stomach.

As a result of concerns and over-caution, the European Chemicals Agency and the European Registration Evaluation Authorisation and Restriction of Chemicals Agency have both decided to limit three types of silicone and to even try and ban them full stop. That is, silicone D4, D5 and D6. 

The entirety of this legal situation seems to be down to a lack of clarity more than anything. This is almost certainly why the Global Silicones Council is launching a campaign against the European Union to try and get it to come around to their way of thinking.

Given that we have the EU uncertain about silicone and incomplete and ambiguous evidence for and against siloxanes, what should we do to relieve everybody's concerns? Actually, I believe there is already an answer. A study by the Technical University of Denmark found that if silicone is cured more intensely, it is much harder for siloxanes to leach out of the silicone.

The process of curing involves turning silicone from its liquid state into a solid-state. Intense curing, more clarity and more regulatory standards all but make for a relatively simple fix to the problem.

It is this regulatory ambiguity that is not unlike the ambiguity surrounding silicone recycling in the first place. All we need to do is shake off the complacency around silicone. 

Summary 

Silicone is here to stay, it's just too important and has many great benefits. For example, it is estimated that for every tonne of carbon dioxide that is released making silicone a further 9 tonnes is prevented from being released due to its application over time. If we recycled silicone more, how much could we lessen our carbon footprint? Silicone is very important for future development, and perhaps even for a transition to a greener world.

We just need to work together to create a culture of recycling and repurposing. And to establish clearer channels of communication, preventing moral panics from getting out of hand in the future.