5 concerns about food & 3D printing
1. Bacteria build-up in the 3D model
This is a major concern because even the smoothest 3D prints have small cracks and spaces where food can get stuck and bacteria can grow. There is a consensus in the 3D printing community on this point, so beware of the small spaces created when printing. If you plan to use the object once and then throw it away there is no problem (except for an environmental problem...). In the case of multiple uses, this can be a problem!
2. Chemicals in the filament
There is a real debate about this, but ABS is generally considered unsafe to use with anything that touches food. That's because ABS contains toxic chemicals that could seep into your food and eventually into your mouth.
Natural PLA is made from corn and is generally considered food safe. However, some companies include other additives (for color or other characteristics) that can be dangerous to ingest. Some PLA filaments are sold as food safe, but it is important to still check with the manufacturer.
3. Toxic particles released during the 3D printing process
According to a 2013 study by the Illinois Institute of Technology and the National Institute of Applied Sciences in Lyon, desktop 3D printers using ABS and PLA plastics are "high emitters" of ultrafine particles (UFP). These particles can exist on the surface of your 3D print and inhalation or ingestion of these excess particles can have adverse health effects.
4. Not dishwasher safe
Ok, so if there is a buildup of bacteria in your 3D printed model, you can wash it and it will be fine! Not so fast.... If you wash your creation in hot water or in the dishwasher, it can warp and even twist over time. PLA is more sensitive to heat and really not dishwasher safe (it can even damage your dishwasher badly!).
5. Some brass nozzles contain lead
Brass 3D printer extruders can contain lead and the contamination can cause health problems. It's not clear how much lead is in the brass and whether a significant amount of lead from the nozzle is transferred during the printing process.Some of the observers seem to think this is a huge problem and others say that the level of lead that would be transferred into the final product is totally insignificant.
It all sounds a bit scary, doesn't it? It is important to keep in mind that these debates are still quite controversial and it is still too early to have concrete conclusions or a clear consensus. Also, there are many things you can do to minimize these concerns. Here are some concrete solutions!
#5 tips for minimizing health risks when 3D printing food
1. Use a food sealant to prevent bacteria build-up
Sealing a 3D model with an epoxy resin or food-safe sealer will cover cracks that can accumulate bacteria. For PLA, the 3D printing industry recommends polyurethane, which you can find at a home improvement store. We also recommend not letting your 3D printed object come in contact with raw meat or eggs, which are more prone to bacteria growth.
2. Buy a filament that is safe because it is suitable for food-grade 3D printing
Many 3D filament manufacturers are launching filaments suitable for food use via PLA, which offers the same heat and impact resistance as ABS. It is also very flexible and does not break easily. There are now a number of food safe filaments on the market, including PP plastic from RepRap in Germany or PETG from FormFutura.
How do you know if your filament is food safe? Your filament will come with a Material Safety Data Sheet (MSDS) that will tell you the chemical properties and should specify if it is FDA approved or food safe. There is a list of approved additives that can come into contact with food. Also, if a company has gone through the food certification process, they will likely indicate this on the packaging.
3. Use warm water with antibacterial soap for washing
Instead of using a dishwasher, wash with warm water and a mild antibacterial detergent immediately after use. This will reduce the risk of melting your print and will also eliminate surface bacteria.
4. Use a food safe extrusion nozzle
To avoid contamination of your filament extruder, you can purchase a stainless steel tip that is considered food safe. This might be a bit excessive if you only plan to use it to print one or two cups. However, if you are very concerned about risk or will be printing a lot of kitchen equipment, then it might be worth it!
5. Limit food contact time
Joseph Larson, a 3D printing blogger contacted the FDA and found out that according to him, food safety really depends on the use of the 3D printed tool. Knives and cookie cutters don't come in contact with food or the mouth for very long and are safe (even without food-grade filament). If you're printing a coffee mug or container that will come in contact with food for longer periods of time, you may want to take extra precautions!