When considering the safety of PETG filament for food-related applications, it’s important to understand what qualifies a material as food safe. Food safety involves factors such as the absence of toxic substances, resistance to leaching, and the ability to withstand cleaning and sanitization processes.
PETG, while related to PET (polyethylene terephthalate), is not automatically considered food safe. PETG does not contain the harmful chemical compound called bisphenol A (BPA), which is often associated with health concerns. However, the use of PETG for food-related items requires additional considerations.
PETG is known to have good chemical resistance and low toxicity, making it suitable for certain food contact applications. However, it’s essential to ensure that the filament used is specifically labeled as food-safe PETG. Not all PETG filaments on the market are explicitly designed for food contact, so it’s crucial to verify the product’s specifications and certifications provided by the manufacturer.
To maintain food safety when using PETG, it’s recommended to adhere to specific guidelines. This includes using dedicated equipment for food-related prints, ensuring thorough cleaning and sanitization of the printed parts, and avoiding contact with harmful substances during the printing and post-processing stages.
By following these precautions and using verified food-safe PETG filaments, you can minimize potential risks
The Ingredients
When it comes to ensuring food safety with PETG filament, it’s crucial to understand the potential risks associated with residual materials and contaminants that may be present in the manufacturing process. These can include plastic additives, pigments, unreacted monomers, or other substances that may come into contact with the material during production.
To address these concerns, PET manufacturing processes have been developed with food safety in mind, and these practices can be applied to PETG as well. PETG is chemically similar to PET, with the addition of glycol to improve printability and reduce warping. The presence of this additional glycol does not have a significant impact on food safety.
However, ensuring the food safety of PETG involves meeting stringent standards throughout the entire production process, including formulation, manufacturing, handling, and printing. It’s important to note that filament manufacturers may not be required to meet the same high standards as materials intended for direct food contact.
To ensure food safety when printing with PETG, it’s recommended to be aware of relevant food safety standards and certifications. Look for filaments that explicitly state they are food-safe and have undergone testing to meet specific regulations. Additionally, follow best practices such as using dedicated equipment for food-related prints, maintaining cleanliness, and avoiding cross-contamination during printing and post-processing.
By being mindful of these considerations and using verified food-safe PETG filaments, you can enhance the likelihood of creating food-contact parts that meet acceptable food safety standards.
Food Safety Considerations
When it comes to choosing filaments for food-contact applications, it’s essential to understand the compliance standards set by regulatory authorities such as the FDA and EFSA. While specific regulations may vary by country, we’ll focus on FDA and EFSA guidelines for this article.
It’s important to note that claims like “Approved by FDA” for filaments are often misleading, as the FDA does not directly approve filaments. Instead, manufacturers should comply with relevant regulations and standards. For example, EU regulation No. 2023/2006 outlines good manufacturing practices for handling, packing, and storing products intended for food contact.
To ensure food safety, look for filaments that explicitly state compliance with specific regulations or standards. We have compiled a list of filaments that meet relevant standards, including options that comply with food safety regulations. When choosing colored filaments, be aware that certain pigments may not be suitable for food applications, so clear filaments are a safer choice.
It’s important to remember that the manufacturing process doesn’t end at the filament factory. As a user, you have a responsibility to ensure food safety in your own printing practices. This includes maintaining cleanliness, using dedicated equipment for food-related prints, and avoiding cross-contamination during printing and post-processing.
By being aware of regulatory standards, choosing compliant filaments, and following proper manufacturing practices, you can help ensure the safety of 3D printed parts intended for food contact.
Print PETG
So assuming you have picked out a filament that was manufactured in compliance with food safety standards, it’s now time to turn our attention to your printing practices. Although, there is also more to this than meets the eye.
Hardware
The first part of printing considerations is the hardware you have. Since it’s going to come into contact with your filament and your printed part, it’s important that all your gear is clean and sanitary.
- Filament storage: Try to store the filaments you plan to use for food-contact parts in a plastic bag or storage box to avoid accidental contamination.
- Filament delivery: Check the extruder gears and the Bowden tube (if you have one) for dirt and debris. If it’s looking icky, then give it a good clean.
- The nozzle: It’s worth giving your nozzle a good clean before printing even if it looks okay. Stainless steel nozzles are preferred because the typical brass nozzles contain lead.
- The print bed: This should also be cleaned thoroughly before printing. You can also consider using a raft to prevent your part from directly touching the bed if yours is not in great shape or you can’t go without adhesion assistance.
Slicing
The second part of consideration comes when you’re slicing your model. Not only do you want to minimize contact of your printed parts with unsanitary equipment, but you also want to be sure that you’re not creating a place where bacteria can thrive.
- Layer height: Within the layer lines is where bacteria love to hang out. Although you’ll sacrifice some printing time, minimizing these micro gaps should be the priority for the safest results.
- Infill: While not strictly necessary, increasing infill could also contribute to minimizing gaps and other places for bacteria to multiply undisturbed. It’s also not a bad idea to err on the side of caution when it comes to designing parts for durability in this case. A small crack is enough to justify retiring the piece from your kitchen.
- Geometry: While slicing, imagine hand washing your model with a sponge. Are there small crevices that may be hard to reach? If so, you should probably consider adjusting the model until you’ll easily be able to clean all of its surfaces thoroughly.
We hope that once you’ve printed your PETG part, you plan to use it a few more times before it starts collecting dust. Naturally, there are a few things to keep in mind when it comes to keeping your parts food-safe.
Post-Print Care
With a freshly printed cookie cutter in hand, spending a few extra minutes on its post-processing can save you a bunch of stress in the long term. With a few simple steps, you can avoid having to reprint the part after a few uses to prevent food poisoning.
As we mentioned, the main area of concern for a printed part is its layer lines. This is why it’s critical to smooth your PETG parts before using them in the kitchen. While sanding is the easiest approach, it’s not recommended as the final step because it creates microscopic scratches on the surface that create the same concern as layer lines.
Ideally, the parts should be coated in a food-safe epoxy once all other post-processing is complete. This fills in layer lines and any other surface imperfections that could cause issues. Prusa Research demonstrates in a video that this method is the most effective approach to creating food-safe 3D printed parts.
When it comes to cleaning these parts after use, opt for handwashing over the dishwasher. With a glass transition temperature of around 85 °C, you’ll risk the part distorting in the heat of a dishwasher. Simple soap and water will be enough to wash an epoxy-coated surface clean. However, avoid washing with very hot water, as PETG is more prone to moisture absorption at higher temperatures.
