Stereolithography is one of the top printing technologies. Resin printing as it is sometimes called, is favored for its ability to produce strong, durable 3D parts. While fused deposition modeling (FDM) might be the most popular printing technology, it does not produce parts as strong as resin printing.
Filament is not as toxic as resin, and does not require as much care when working with it. While filament might be safer, especially for beginners, both filament and resin have been linked with an increased likelihood of developing cancer.
But just how likely are you to develop cancer from resin printing? Today we want to explore how harmful resin printing is. We want to look at how toxic liquid resin is compared to cured resin. We also compare the toxicity of resin versus a filament like PLA.
If you want to know how much risk resin printing carries, then this article will answer some of your questions.
We also highly recommend that you check out our post titled “Do 3D Printers Cause Cancer? Risk & What You Must Know!“
Is Resin For 3D Printing Harmful?
Resin is potentially harmful if mishandled or if precautions are not taken when using or disposing of it. Inhalation, skin contact and ingestion are the biggest risks when working with resin. They can all cause short term discomfort or possible long term illness.
Resin is potentially hazardous to both you and the environment and should always be handled with care. It is particularly harmful during the printing process when it is in its liquid form.
How Toxic Is Liquid Resin?
3D printer resin is a thermoset liquid that hardens when exposed to UV light. This process of curing a liquid resin releases toxic fumes that are harmful when inhaled. The liquid resin itself is also harmful when it comes into contact with the skin.
Vat polymerization or resin printing as it is simply known, uses either a laser or a light to harden a liquid resin. Just like how melting filament produces toxic fumes, curing resin releases Volatile Organic Compounds (VOC) and Ultra Fine Particles (UFP).
Unlike filament, however, resin produces up to six times more of these dangerous compounds. Prolonged exposure through inhalation has been linked to long term respiratory illnesses like bronchitis. Source
Ultra Fine Particles are nanoparticles thinner than a length of hair. These nanoparticles are fine enough to get absorbed by the cells lining your lungs. This will affect your cardiovascular system and lead to chronic illnesses like asthma.
A more serious concern is the link between 3D printing and cancer. According to research, exposure to the fumes produced from 3D printing is up to three times more likely to lead to cancer compared to exposure to urban air pollution. Source
Filament is made of solid plastic. Except for the melted plastic, it is completely safe to touch. This is not the case with resin which contains additives like isooctyl acrylate, HDODA, and HEMA which can cause severe skin irritation. Source
Resins contain the same additives you find in petroleum products like diesel and gasoline. These are easily absorbed into the skin and over the long term will eventually lead to contact dermatitis or skin damage.
It goes without saying that anything toxic when inhaled should not be ingested either orally or by accidentally getting it in your eye. Resin does not easily wash off so your eyes are the last place you want it to be.
How To Print Safely With 3D Printer Resin?
Observing safety precautions is more critical when printing with resin than when printing with filament. Some of the safety precautions are the same as you would follow for printing with filament with a few more thrown in for extra measure.
Print in a safe environment
Avoid printing in a common living area. These are places where you spend a lot of time. Some examples of places where you want to avoid printing are your bedroom and your living room.
Good examples of places to print are your basement or garage. These are less trafficked areas that reduce exposure to the fumes produced by a 3D printer.
Provide adequate ventilation
While you need to print away from living spaces, you also need to ensure you print in a well-ventilated space. Print close to the window if possible. Use a fan to blow the fumes out the window.
Use an air monitor to keep tabs on the levels of particulate in the air. Use an air purifier to filter the air when the levels of VOC and UFP get dangerously high. Coupled with a print enclosure, an air purifier will make your print environment far much safer.
For more on this, check out our post “Do 3D Printers Need To Be Vented? What Every Owner Must Know!“
Wear protective gear
This is far more important for resin than it is for filament. Wear rubber gloves with long sleeves to protect your hands from coming into direct contact with the resin.
Wear a dust mask or respirator to protect yourself from the fumes produced when you print. You should also wear glasses or goggles to stop any resin landing in your eye.
Use environmentally-friendly resin
There are types of resin that are bio-based and less toxic. While having similar qualities as standard resins, they have the distinctive quality of being less harmful to the environment.
On a side note, check out “What Happens If You Run Out Of Resin During A Print? (Solutions)“
Is Cured Printer Resin Toxic?
Cured resin is liquid resin that has been hardened. Resin loses most of its toxicity when it is cured. This is the safest way to dispose of resin. The simplest way to cure resin and make it non-toxic enough to dispose of it is to cure it in direct sunlight.
Liquid resin is highly toxic to the environment and should never be disposed of while still in a liquid form.
Is PLA Resin Toxic?
PLA is one of the least toxic materials for 3D printing. While it still produces toxic fumes when melted, it produces less than other materials like ABS or PETG. This is primarily down to the plant-based nature of PLA. Unlike ABS which is petroleum based, PLA is made from plant material like cornstarch.
This is a key characteristic of PLA, especially for printers that might be used by children. If you are worried about the harmful effects of the materials used in 3D printing, PLA is possibly the least harmful material to work with.