Is PLA Food Safe? or are 3D printed materials safe to use in kitchen is a very common question that arises for people that are interested in 3D Printing. The best thing about 3D Printing is, it provides you endless possibilities of printing.
But when it comes to printing with PLA Filament for 3D objects relating to kitchen utensils such as spoons, cups and things like storage boxes lot of people are concerned about the safety issues. Most of the people are not sure whether PLA filament printed kitchen utensils are safe or not? Let us go for one liner answer before going into details.
Is PLA Food Safe?
Yes, Strong yes PLA filament printing is safe for food. However there are certain things that you need to take care and be aware of.
Some of the things that you need to take care of while using PLA for food:
- Make sure that printed object is as smooth as possible. It will avoid bacterial spaces.
- Avoid use of Extra Additives with PLA filaments.
- Stainless steel nozzle is recommended for 3D Printer.
- Ensure the cleanliness of printer nozzles before printing.
- Never use PLA filament with dishwasher.
- Last but no least you can use food safe epoxy resin.
Article highlights (Is PLA Food Safe?)
The below article will try to answer the question in detail Is PLA Food Safe? Further we will also discuss some interesting facts & information about PLA Filament widely used for 3D Printing. In the last phase we will also discuss whether it is recommended to use PLA printing for kitchen utensils. Another important issue relating biodegradability of PLA will also be addressed.
Let us start first from understanding what actually PLA Filament is?
What is PLA Filament?
Polylactic Acid or commonly known as PLA is basically a 3D Printing filament. Main reason of popularity of PLA Filament is because it is made up of natural materials.
PLA is generally obtained from natural materials such as corn or potatoes etc. Lactic acid on the other hands also plays important role in our daily life. Lactic acid in body stimulates glucose production and during exercise also helps in weight loss.
We can get lactic acid from anything that has glucose. We all know corn is one of the preferred sources of glucose that is why corn is increasingly used in production of PLA filaments. Therefore it is obvious that PLA print materials are derived natural materials and can be considered safe for printing.
But do you think the answer to question is PLA Food safe? is that simple or there are few more things that you need to be aware of. First we will try to understand what actually Food Safe means?
Related Article : How long Does PLA Filament Last?
What Food Safe Means?
It is important to understand some basic terms before going in detail about Safe Food.
What is Food Quality?
Generally Food Quality does not refers to the single characteristic that the Food should have. It is a broad term that is used to define variety of characteristics of food.
But an easy way to define food quality is “if the food is not harmful for human health” it is of good quality.
What are Food Contact Surfaces or Surfaces?
The term Food Contact Surface here refers to all those surfaces that come in contact with each other during printing of food related objects normally printing of kitchen utensils through 3D printing. The surfaces that come in contact with each other are for example the contact of components of 3D printer with 3D printed object and that of 3D printed object with food.
When these surfaces come in contact with each other several particles are transmitted between the surfaces. Therefore more and more the surfaces come in contact with each other greater are the chances of transmission. Therefore classification of food is generally considered with those items that come in contact with food over a longer period of times. Some of the examples are plates, utensils and food storage containers etc.
Now move and understand when a material can be considered as Food Safe.
When a Material Can be Considered as Food Safe?
We can consider a material food safe if it does not raise any health concerns after coming in contact with food surfaces. In addition to not raising any health concern the material should also not effect the taste and smell of the food.
In order for the material to be declared as food safe it should meet at least following conditions and requirements:
- No harmful substances should transmit when surfaces come in contact with each other and with food.
- Also it should always be ensured that color, odor or taste of the material is not transmitted.
- The material has no harmful effects when used
- Another important characteristic is material should be durable and corrosion resistant. Also it should be hundred percent non absorbent.
- During washing the quality of the material is not damaged in any way. Even after multiple washes.
- Also material needs to have smooth surface that can easily be cleaned.
- Material used should not distort, decompose or develop hairline cracks etc.
Since we understand what should be considered as Food Safe Material? We can move to why food safety is such a big concern in 3D Printing.
Why Food Safety is of so much importance in 3D Printing?
Now a days almost all the things are 3D Printable ranging from complex aerospace equipment’s to simplified items like kitchen utensils. However for 3D printed objects that come in contact with food directly safety is of great importance. It has to be ensured that material is hundred percent safe for human health when it comes to contact with food directly. It will not only ensure your heath but also saves the food from getting useless and wasted.
3D printer materials are also used for medical purposes. Therefor only bio-compatible materials that are safe for human heath are used.
Therefore although there is no doubt that 3D printing has provided us with lot of options for various industries. But in no way the importance of material that is used for printing can be ignored. When it comes to human health and safety nothing matters more then that. That leads us to the conclusion that selection of right materials is highly important in 3D printing. This selection needs even more attention when printed objects are used for purposes that can directly impact human health such as food and medical industry.
Let us discuss bit more in detail about the risks involved in 3D printer food related objects.
What are the Food Safety Risks Involved in 3D Printing?
We will discuss 3 most significant risks to food safety in 3D Printing:
- Risk Of Bacterial Growth
- Risks from Printing Process its Self
- Risks from Chemicals used in Materials themselves
Risks Of Bacterial Growth
Lot of 3D objects that we print come in to direct contact with food. For example kitchen utensils etc. Therefore you definitely do not want any bacterial growth in 3D objects that may make your food contaminated.
Generally bacteria have high chances of growth if the printed object surface is not smooth. Uneven surface provide room for bacterial growth. Even if the surface is smooth bacterial growth can still take place if the object has sharp edges where particles of food get stored. These particles lead to growth of bacterial and ultimately results in making food contaminated.
Risks from Printing Process itself
The process of 3D printing involves a combination of chemicals used in filament and heating process. That is why we should be extra careful about what chemicals are used in making of those filaments.
This needs to be further taken care when you know that these printed 3D Materials are going to get in contact directly with the food.
Risks from Chemicals used in Materials themselves
Another safety risk that is involved in 3D printing is from chemicals used in printing materials themselves.
Among all the filaments used in 3D printing ABS filaments are considered to be the most unsafe or toxic. As ABS filaments contain high proportion of fine particles. These ultra fine particles can cause harm to human health when digested.
Therefore it is advisable to avoid ABS filaments for printing of 3D objects that come in contact with food items.
Now lets discuss how safe is PLA filaments for food safety.
Is PLA Food Safe? Result of Tests:
As with other filaments, PLA is also tested under various conditions to assess how safe it is for human health when used in printing? Testings were performed under various temperatures. The tests also involved how PLA printed objects performed when they came in contact with food items. The duration of contact was also varied for further detailed results.
The results showed that PLA releases small amount of lactic acid in to food. Lactic acid is a common food ingredient that is even present in corn and breast milk.
However the quantity released by PLA is not dangerous. To further elaborate the quantity of lactic acid released by PLA during printing is 700 times less then lactic acid found in breast milk.
Chances of contamination during Printing Process – PLA
There has been reports about contamination of PLA by hot ends of 3D Printers. Printing process involves mixture of heating and chemicals that can results in contamination from printer nozzles. Stainless steel Nozzles are exception when it comes to contamination through nozzles. Therefore both PLA and ABS are not hundred percent safe. As printing from them release ultra fine particles.
These ultra fine particles are then transmitted to the printed object and from printed objected it is passed to food directly. These particles can cause harm to human health.
it is also advisable not to stand too close to 3D printers while printing. These particles can easily pass on to your food making it harmful for health.
Additives used in PLA – Harmful or Safe
We all know that PLA is coloured. That means it contains certain additives for colour and strength optimization. One way to stay safe is to print with PLA that is made up of natural and untreated materials. The best way to know whether the PLA is made up of natural material or has additional additives is to review safety data sheet.
The data sheet will provide you with useful information about chemical properties and whether it is FDA approved or not.
Inadequate Surface of 3D Objects
All 3D printed objects have tiny pores on their surfaces. These surfaces provide good breeding grounds for bacteria that are harmful for human health.
Same goes for PLA printed objects. PLA printed objects also have tiny pores on their surfaces. Thus bacterial growth is hundred percent possible. Furthermore PLA is also not dishwasher-safe and therefore it is not possible to wash the surface to get rid of these bacteria. That lead us to believe that PLA should be used for once only and also for simple things like water for better safety.
Therefore PLA printed objects that are disposable such as disposable cups and plates are generally safe as chances of bacterial growth are minimum. That is why completely avoid repeated use of PLA printed objects.
Another good way of discouraging bacterial growth on PLA printed objects is to cover the printed objects with food grade epoxy or sealant. This fill up the gaps where any possible bacterial growth can take place. Generally polyurethane is considered most suitable for this purposes. A good thing about it is that it is easily available in most hardware stores.
Further also always ensure that printed 3D objects do not come in contact with food items like meat or eggs as these items are more suitable for bacterial growth.
Although PLA printed objects are not suitable for dishwasher this does not mean that we can not wash it under any circumstances. By using lukewarm water and mild detergents we can still wash PLA printed objects and reduce chances of any bacterial growth.
Still PLA is widely used for printing 3D objects relating to food mainly because it is made up of natural materials mainly corn starch etc
Talking about the biodegradability of PLA it is basically dependent on 3 main factors:
- Microbes Growth
These elements result in visible degradation of PLA generally within 1 year. In high temperatures and with the presence of large number of microorganisms, PLA start decomposing. This may result in compost heap but it should provide a temperature of 60 degree Celsius that is PLA glass transition temperature.
If the 3D printed objects are placed in compost heap it takes around 6 months before we can see visible differences in the form of cracks and decay. On the other hand if PLA is kept at room temperature it may take several years before it decomposes. However time time can get shortened if the object is exposed to sunlight. Even if we ignore heating effect of sunshine still UV lights of sun makes the material to lose its original colour and become pale.
Now coming to the final point that whether this process of biodegradability of PLA printed objects is good or bad? For me it is entirely dependent on your own perspective of things. As per the principles of sustainable development, biodegradable objects are the best since they return to nature ultimately. Especially where objects are supposed to disappear after certain period of time as in bone surgeries.
In case the 3D printed objects are not required to change, it is also manageable. As mentioned above the bio-degradation requires various conditions that are not present everywhere. Further we can prolong the use by keeping PLA printed objects in a cool and dry environment.
- There is absolutely no doubt that PLA is biodegradable due to its natural origin. Also PLA is compo-stable since various microorganisms use PLA as food source.
- For biological decomposition of PLA there are certain conditions such presence of moisture, high temperatures and microorganism. These elements are commonly found in garden soil.
- If PLA is kept in good conditions, visible signs of PLA bio degradation appears after a period of around 6 months.
- PLA can last for hundreds of years under normal room conditions.
Just to further conclude the discussion whether we can use 3D printed objects for kitchen utensils can not be answered with simple Yes or No. Before using 3D printed objects you should fully understand the associated risks which is also the purpose of this article.
Certain objects like knives and cookie cutters never come in contact with food directly therefore there is no harm in using them with 3D printing. For other objects that come in contact with food directly there are additional precautionary measures.
This article is only intended to improve your understanding regarding use of 3D printed objects and also if PLA is food safe.