Everything You Need to Know About Food Safe 3D Printing

3D printing has taken the food industry by storm in recent years. Using 3D printing to create meat, fish and desserts has never seemed easier. However, using 3D printers to make food is not the only way additive manufacturing is being used in the food sector. 3D printing can also be used to create parts that come into contact with food, such as plates, cutlery and even packaging. Of course, if a part, even one made with 3D printing, is going to be used with food, it must be “food safe.”

But what does food safe actually mean? What are the most important considerations when it comes to 3D printing? In the guide below it answers these questions and takes a closer look at how users can ensure their 3D printed parts are food safe. More specifically, it focues on polymer additive manufacturing because although ceramics and metals can also be considered food safe, plastics are generally more readily available, especially for non-industrial additive manufacturing.

What is Food Safe?

When it comes to food safe 3D printing, it's important to first define what food safe actually is. Generally speaking, the term "food safe" of a material is a status indicating that the material is permitted to come into direct contact with food. Any material that is said to be food safe will meet certain requirements determined by its intended use and will not pose a food safety hazard. Although these will also vary by country.

Generally speaking, to be considered food safe, a part must have the following characteristics. Anyone wishing to use 3D printing for parts that come into contact with food safe must follow the following guidelines: No migration of harmful (causing harm or damage) substances; No impart colour, odour or taste; Be safe under normal conditions of use; Be durable, corrosion-resistant and non-absorbent;Be heavy enough to withstand repeated washing; Be finished so as to have a smooth, easy-to-clean surface, free of breaks and sharp internal corners; Be resistant to pitting, chipping, scratching, scratching, deformation and breakdown.

Is PLA Food Safe?

Before getting into the process itself, one of the most important factors to consider when looking into food safe 3D printing is material selection. This is especially true for plastics, as many have raised concerns in recent years that this range of materials allows chemicals to leach into food, not to mention the larger discussion about microplastics in the body. Still, there are many polymers that can be used. The most widely used polymer in domestic 3D printing is undoubtedly PLA. The material is prized for its ease of printing and its biodegradability (under the right conditions). But will it come in contact with food? Well, there's no easy answer. Technically, pure PLA without colouring or other additives is defined by the FDA as food safe. However, if the PLA is coloured, then these additives can leach chemicals, making it no longer safe for food. There are other factors that make it inappropriate. It is worth noting that we can point to the low melting point of this material, which makes it unsuitable for parts that may come into contact with heat (such as coffee cups or things designed for microwave ovens). That is to say, it cannot be placed in the dishwasher and cannot be washed properly, meaning the part may need to be used once to avoid bacterial contamination. These factors make PLA not the most food-friendly material, even though it is classified as safe by the FDA.

Of course, PLA isn't the only material that can be considered food safe. Other polymers on the FDA's list of food safe polymers include polypropylene, PETG (PET is the material used in plastic bottles, although PETG, like PLA, is only food safe if additives such as colour are not present in the filament ), PA11, PA12 and silica gel. These more industrial materials may be safer than standard thermoplastics like PLA. Of course, even if a material is food safe, that doesn't mean the final part will be safe enough, which depends on the process used to make it.

How to Ensure Food Safe with 3D Printing?

As mentioned before, materials are only the first step in ensuring food safe 3D printing. Even if you are using FDA-approved materials, the 3D printing process itself may contaminate the part and mean it will no longer be considered food safe. Let’s look at how 3D printing with FDM, SLS or Resin affects the final part. FDM 3D printing remains the most popular process today and the one manufacturers are most likely to see when making parts that may come into contact with food. But the process itself is not necessarily food safe. That's why certain considerations should be kept in mind. First, in terms of nozzles, most 3D printers will have a brass nozzle. But some of them have been found to contain trace amounts of lead. The safest option is a stainless steel nozzle, as this material is FDA approved and does not contain PTFE tubing (as Teflon is toxic at high temperatures). It is also recommended to use a direct extruder instead of a Bowden. Additionally, it is crucial that before 3D printing any parts for food use, the 3D printer must be thoroughly cleaned to remove any potentially toxic residual material and ensure no bacterial growth. That being said, even with all of these safety considerations, FDM 3D printing is not considered a very food safe 3D printing process. The reason is that the nature gaps will be left in the part, especially between layers. These, in turn, can become areas for bacterial growth, rendering the part no longer food safe. It is for this reason that it is recommended that food parts made from FFF be single-use or require reprocessing. Regardless, it's safe to say that while food safe 3D printing is certainly possible, it's not without risks.

When it comes to anything that comes into contact with food, safety considerations must be a top priority to ensure the health of those who eat it, which is why everything that comes in contact with any consumable product goes through so many tests. However, if you keep these factors in mind and make sure you're using food-safe materials, you can look forward to using your 3D printer to create parts like novelty cookie cutters and even tableware. What do you think are the most important considerations for food safety 3D printing? Do you manufacture food contact parts?