3D Printers

3D printing is a relatively new manufacturing process that creates objects layer by layer using materials such as plastic filaments (“ink”) and liquid resins. The two most common types of 3D printers used in education, hobbies, and industry are Fused Deposition Modeling (FDM) printers and Resin-Stereolithography (SLA) printers. These printers are commonly found in homes, schools, offices, libraries, and manufacturing facilities and can release a variety of harmful particles and chemicals into the air that can be harmful to health. 

How Do 3D Printer Emissions Affect Health?

One major concern is the release of particulate matter or ultrafine particles (UFPs), which are tiny airborne particles smaller than 0.1 microns. These particles are generated by 3D printers when plastic filaments are heated and melted during the printing process. Because they are so small, these UFPs can remain suspended in indoor air for long periods and can easily be inhaled. When inhaled, these tiny particles can travel deep into the lungs, damage lung cells, and even enter the bloodstream. 

3D printers also release volatile organic compounds (VOCs) during heating and printing. The VOCs of concern emitted by 3D printers include formaldehyde (a known human cancer-causing agent called a carcinogen), caprolactam, and styrene (possible human carcinogen).  Repeated exposure to VOCs may increase chronic respiratory inflammation. 

The type and amount of VOC emissions vary depending on the filament material, printer type, printing temperature, and ventilation conditions. For example, ABS (Acrylonitrile Butadiene Styrene) filament is a popular petroleum-based thermoplastic used in products like LEGO bricks and protective helmets. ABS produces relatively high levels of styrene and UFP emissions. PLA (Polylactic Acid) filament, another common and beginner-friendly material made from renewable resources such as cornstarch and sugarcane, produces lower emissions than ABS; however, PLA still releases particles and VOCs into the air.

Resin printers present additional concerns. These printers use liquid chemical resins to create highly detailed models, jewelry, and miniatures. The resin hardens, or “cures,” when exposed to ultraviolet (UV) light. During printing and curing, resin printers can release VOCs and chemical vapors.

Health effects associated with poor indoor air quality from 3D printer emissions may include:

• Headaches, dizziness, or confusion
• Eye, nose, and throat irritation 
• Skin irritation
• Coughing and wheezing 
• Shortness of breath 
• Chest tightness 

More serious health effects may include:

• Asthma or COPD exacerbation 
• Chronic respiratory disease 
• Central nervous system effects 
• Cardiovascular disease and stroke 
• Cancer 

Most research on the health effects of 3D printing has focused on adults. However, an EPA predictive modeling study found that individuals between 9 and 18 years old may be at the greatest risk from exposure to 3D printer particulate matter and VOCs.

How Long Do Pollutants from 3D Printers Stay in the Air?

Ultrafine particles and VOCs released during 3D printing can remain suspended in indoor air for hours after printing has stopped. Because these particles are extremely small, they settle slowly onto surfaces. The concentration and persistence of these pollutants depend on several factors, including:

• Printer type 
• Filament or resin material 
• Print duration 
• Number of printers operating 
• Room size and temperature 
• Ventilation and air exchange rate 

How Can You Reduce Exposure?

Reducing exposure to 3D printer emissions typically involves a three-step approach: source control, ventilation, and air cleaning. Indoor air quality sensors may also help monitor levels of particulate matter and VOCs before, during, and after printing.

Control the Source

1. Choose lower-emission filament or resin materials whenever possible. 
2. Use fully enclosed printers to help contain emissions. 
3. Limit the time spent observing close to the 3D printer while it is operational.  Do not hover near the printer but consider cameras for observations.  
4. Avoid operating printers in occupied spaces such as bedrooms, classrooms, or offices. Use dedicated printing rooms when possible.  Keep the doors closed while printers are operating. 
5. Maintain printers according to manufacturer recommendations to prevent overheating and excess emissions. 
6. Wait until the printer has cooled, and emissions have dissipated (at least 2 hours but up to 24 hours in a small, unvented room) before accessing the product or cleaning up.
7. Vacuum floors, surfaces, and furniture frequently using a vacuum with high efficiency filtration (HEPA) vacation.      
8. Wash hands to avoid hand-to-mouth transfer of chemicals and particles, especially before eating. 

Improve Ventilation Before, During, and After Printing

1. Open windows and doors to increase fresh air ventilation. 
2. Use fans to direct contaminated air outdoors. 
3. Install mechanical exhaust ventilation systems that vent particles and VOCs from printers directly outside when possible. 

Use Air Cleaning and Filtration

1. Run portable HEPA air cleaners during and after printing to reduce ultrafine particle levels. 
2. Use air cleaners that include activated carbon filters to help reduce VOCs and chemical odors. 
3. Replace air cleaner filters regularly according to manufacturer's recommendations.

Universal Laboratories has published guidance on the safe use of 3D printing for institutions of higher education.