Is 3D Printing Safe for Food Contact?

At Forefront Filament, our filaments are made from 100% polyolefins. That is, a mixture of polypropylene (PP) and polyethylene (PE e.g. LDPE and HDPE). These plastics are amongst the most widely used plastics in the world, and many of those uses are in food contact applications – plastic cutlery, crockery, Tupperware, thermoformed trays, films, pouches and bottles can all be made from polyolefins. Fundamentally, polyolefins, and many other plastics, are “food safe”.

So can you use “food safe” plastics to make 3D printed products that are also “food safe”?

The short answer is no… and yes.

While some filament manufacturers even label their products “food safe” (in the EU) or “FDA approved” (in the US), there are some fundamental features of 3D printing that mean that the final printed part can’t meet the same regulations.

We’ll take you through some details first, but we’ve also written a handy summary at the end.

3D print layers can create microscopic bacterial breeding grounds

FDM and SLS processes, by their nature of layer-by-layer building, leave tiny holes, creases and crevices that are just perfect for moisture to get trapped in, creating nice warm environments for bacteria to thrive. Therefore, printing something that you’d want to use again and again in food contact could increase risk of contamination.

However, this only becomes a problem after food/moisture gets into the crevices and is left there for a while. Therefore, single use items (that are then recycled) should be fine, or something like a cookie cutter is only in contact with the food for a short time before the food is baked, would limit the likelihood of contamination. Also, dry, solid foods are less likely to get into the minute cracks than powder or liquids, and will be easier to wash off.

Another option is to seal the surface of the print to reduce number of places for bacteria to hide. Food-grade sealants fill in all the tiny gaps between the layers. These are available from kitchen shops and some DIY shops, but as with any chemical – always read the label!

Some filaments contain toxic elements

Some 3D printing materials contain toxic components that wouldn’t be great for you if you ingested them. ABS for example, and many of the TPU-based flexible filaments, can leach chemicals into any food or drink in contact with them, which you wouldn’t want inside you. Even after changing filament, there may still be residues of these toxic filaments lurking in your nozzle.

There are a range of “safer” choices of filament for food contact applications, including pure PLA, pure PET and, of course, all of the thermoplastic polyolefin (TPO) filaments from Forefront. So don’t take the risk with ABS, choose something cleaner, wash your print in warm-to-hot soapy water and limit your use of the item to occasional, rather than everyday usage.

Toxic particles can be emitted from the 3D printing process

Another thing to be aware of is something called “UFP” or Ultra-Fine Particles. These are likely to be emitted from your FDM printer with almost any filament, and could also exist on the surface of the printed part. These particles of plastic chemicals are small enough to get into your lungs and even your blood stream, but are not filtered out naturally by the body, so long term exposure could cause complications later on.

The amount of UFP released depends hugely on your printer and choice of filament. According to a study by the Illinois Institute of Technology (which you can read about here, ABS and Nylon are the highest emitters.

However, the exposure likely from even the worst UFP emitters in 3D printing are still a long way off the exposure you’re likely to get driving in a car on any city road. If you are worried, invest in an air filtration system and wash all of your prints before using them in any food or liquid contact applications.

How clean is your nozzle?

Quite apart from the toxic filaments that might have passed through your 3D printer nozzle, the nozzle itself could contain traces of lead, particularly if it a brass nozzle.

Stainless steel nozzles are available, and these are also used in the new 3D food printers that are becoming available. If you do a lot of food-contact printing, it is possible to keep contamination to a minimum by switching to a stainless steel nozzle.

In Summary

Can I print parts for food contact?

Yes, but:

·        choose the right filament (see below)

·        print parts that can be easily cleaned, and clean them before first use

·        print parts that only come into contact with food for a short time

·        print single-use or infrequent-use items

Which Filament is best for food-contact applications?

Choosing a filament that is:

·        Inherently food-safe before printing

·        Water and moisture resistant (reducing bacterial home creation)

·        High temperature resistant (to allow hot water washing or even dishwasher-compatibility)

·        Recyclable (to reduce waste from single-use applications)

Fortuitously Forefront polyolefin filaments F41 FLEX and F43 TOUGH meet all of these criteria - buy your filaments here and begin creating kitchen masterpieces!